Susumu Ohtsuka

Last Updated :2024/06/05

Affiliations, Positions
., Professor
E-mail
ohtsukahiroshima-u.ac.jp

Basic Information

Academic Degrees

  • Doctor of Agriculture, The University of Tokyo
  • Master of Science, Kyoto University

Educational Activity

  • [Bachelor Degree Program] School of Applied Biological Science : Department of Applied Biological Science : Integrative Hydrospheric Science Program
  • [Master's Program] Graduate School of Integrated Sciences for Life : Division of Integrated Sciences for Life : Program of Bioresource Science
  • [Doctoral Program] Graduate School of Integrated Sciences for Life : Division of Integrated Sciences for Life : Program of Bioresource Science

Research Fields

  • Agricultural sciences;Applied aquatic science;Aquatic life science

Research Keywords

  • Taxonomy
  • Ecology
  • invertebrate
  • Symbiosis
  • Phylogeny
  • fish
  • Mysids
  • Copepods
  • parasite
  • Jellyfish

Affiliated Academic Societies

Educational Activity

Course in Charge

  1. 2024, Liberal Arts Education Program1, 2Term, Introduction to Field Sciences
  2. 2024, Undergraduate Education, 3Term, Seminar in Field Science
  3. 2024, Undergraduate Education, 4Term, Introduction to Hydrospheric Biodiversity
  4. 2024, Undergraduate Education, Intensive, Practical Work in Hydrospheric Field ScienceII
  5. 2024, Undergraduate Education, Second Semester, Graduation Thesis I
  6. 2024, Undergraduate Education, First Semester, Graduation Thesis II
  7. 2024, Undergraduate Education, Second Semester, Graduation Thesis III
  8. 2024, Undergraduate Education, Intensive, Seminar in Fildwork on Community Coasts
  9. 2024, Undergraduate Education, Intensive, Practice on economic marine invertebrates and seaweeds in the Seto Inland Sea
  10. 2024, Undergraduate Education, Intensive, Practice and Field Work in Fisheries Science
  11. 2024, Undergraduate Education, Year, Special Practice I
  12. 2024, Undergraduate Education, Year, Practical Course in Marine Bioscience and Technology IV
  13. 2024, Undergraduate Education, Year, Practice on East China Sea Study
  14. 2024, Undergraduate Education, Year, Practical Course on Fisheries Science and the Marine Environment I-B
  15. 2024, Undergraduate Education, Year, Practice Course on Fisheries Science and the Marine Environment III
  16. 2024, Undergraduate Education, Year, Practical Course in Marine Bioscience and Technology I
  17. 2024, Undergraduate Education, Year, Practical Course in Marine Bioscience and Technology II
  18. 2024, Undergraduate Education, Intensive, Practice Course on Fisheries Science Data Analysis I
  19. 2024, Undergraduate Education, Intensive, Practice Course on Fisheries Science Data Analysis II
  20. 2024, Undergraduate Education, Second Semester, Practice on Primary Production (Plankton and Benthos) in the Marine Ecosystem
  21. 2024, Graduate Education (Master's Program) , 1Term, Exercises in Bioresource Science A
  22. 2024, Graduate Education (Master's Program) , 2Term, Exercises in Bioresource Science A
  23. 2024, Graduate Education (Master's Program) , 3Term, Exercises in Bioresource ScienceB
  24. 2024, Graduate Education (Master's Program) , 4Term, Exercises in Bioresource ScienceB
  25. 2024, Graduate Education (Master's Program) , Academic Year, Research for Academic Degree Dissertation in Bioresource Science
  26. 2024, Graduate Education (Master's Program) , 2Term, Fisheries Oceanography I
  27. 2024, Graduate Education (Master's Program) , 4Term, Fisheries Oceanography II

Research Activities

Academic Papers

  1. Does the Kuroshio Current transport planktonic larvae of the hydrothermal-vent crab Xenograpsus Takeda & Kurata, 1977 (Decapoda: Brachyura: Grapsoidea)?, JOURNAL OF CRUSTACEAN BIOLOGY, 42(1), 1-8, 20220301
  2. Ultrastructure of the mouthpart sensory setae in mesopelagic copepods of the family Scolecitrichidae, Plankton Biology and Ecology, 44, 81-90, 19970401
  3. Evolutionary switching from suspension feeding to carnivory in the calanoid family Heterorhabdidae(Copepoda), Journal of Crustacean Biology, 17(4), 577-595, 19970401
  4. A new species of Tortanus (Atortus) (Copepoda : Calanoida : Tortanidae) from Rodrigues Island, Mauritius, JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM, 83(2), 355-360, 2003
  5. A new species of Neoscolecithrix (Crustacea; Copepoda; Calanoida) from off Okinawa, southwestern Japan, with comments on the generic position in the superfamily Clausocalanoidea, Bulletin of National Science Museum= Tokyo= Series A, 29(2), 53-63, 20030401
  6. Tide-induced reworking of planktonic foraminifers on the outer shelf and slope off Miyako Island, southern Japan: preliminary results, Journal of Science= Hiroshima University= Series C, 11(2), 239-246, 20030401
  7. A New Asymmetrical Near-bottom Calanoid Copepod, Paramisophria platysoma, with Observations of Its Integumental Organs, Behavior and In-situ Feeding Habit, Bulletin of the Plankton Society of Japan, 36(2), p87-101, 199002
  8. In situ feeding habits of Oncaea (Copepoda: Poecilostomatoida) from the upper 250 m of the central Red Sea, with special reference to consumption of appendicularian houses, Bulletin of the Plankton Society of Japan, 43(2), 89-105, 19961225
  9. Density of juveniles of trials-spine horseshoe crab Tachypleus tridentatus in Sone Estuary, Kitakyushu, Japan, with notes on sediments particle sizes in habitats and breeding areas, 15, 1-7, 20171020
  10. Possible mimicry in the galaemmatid bivalve Scintilla philippinensis (Bivalvia: Galaemmatidae) to nudibranchs and crabs, Venus, 75, 93-98, 20171127
  11. Morphological and molecular analyses of Blackfordia sp. (Hydrozoa: Leptothecata) newly discovered in Vietnam, PLANKTON & BENTHOS RESEARCH, 16(2), 118-128, 202105
  12. Four new dendrochirotid holothurians collected from the Seto Inland Sea and the western part of the Sea of Japan, western Japan, ZOOTAXA, 5023(1), 1-43, 20210817
  13. A new genus and species of the family Pennellidae (Copepoda, Siphonostomatoida) infecting the Pacific viperfish Chauliodus macouni, PARASITE, 25, 20180209
  14. Poecillastrin H, a Chondropsin-Type Macrolide with a Conjugated Pentaene Moiety, from a Characella sp Marine Sponge, JOURNAL OF NATURAL PRODUCTS, 81(5), 1295-1299, 201805
  15. Possible origins of planktonic copepods, Pseudodiaptomus marinus (Crustacea: Copepoda: Calanoida), introduced from East Asia to the San Francisco Estuary based on a molecular analysis, AQUATIC INVASIONS, 13(2), 221-230, 201806
  16. Piscivory of the Japanese giant box jellyfish Morbakka virulenta, PLANKTON & BENTHOS RESEARCH, 13(2), 66-74, 201805
  17. Comparison of animal communities on benthic and drifting brown algae Sargassum horneri in the Seto Inland Sea, Japan, 11, 7-13, 20191225
  18. Interactions between zooplankters and bacteria (Review), 66, 86-100, 201908
  19. Zoogeography of pelagic copepods in Japan and its adjacent waters, Bulletin of Plankton Society of Japan, 46(1), 1-20, 19990401
  20. Three new species of the demersal calanoid copepod Pseudocyclops form Phuket, Thailand, Plankton Biology and Ecology, 46(2), 132-147, 19990401
  21. Introduction of the Asian copepods Acartiella sinensis, Tortanus dextrilobatus(Copepoda : Calanoida),and Limnoithona tetraspina(Copepoda : Cyclopoida) to the San Francisco Estuary, California, USA, Plankton Biology and Ecology, 46(2), 128-131, 19990401
  22. Seasonal changes of zooplankton community in Honjyo area and its neighboring waters of Lake Naka-umi, Laguna, 6, 73-87, 19990401
  23. Feeding habits of zooplankton, in particular, copepods in Lake Naka-umi, Lagund, 6, 89-105, 19990401
  24. The identity of Limnoncaea diuncata Kokubo, 1914 (Copepoda : Poecilostomatoida) from Hokkaido, Japan, with the relegation of Diergasilus Do, 1981 to a junior synonym of Thersitina Norman, 1905, SYSTEMATIC PARASITOLOGY, 57(1), 35-44, 2004
  25. A new species of the deep-sea copepod genus Scutogerulus (Calanoida: Arietellidae) from the hyperbenthic waters of Okinawa, Japan, Systematics and Biodiversity, 2(1), 49-55, 20040801
  26. First record of the occurrence of an ellobiopsid Thalassomyces marsupii Kane on a new host of hyperiid amphipod in Japanese waters, Plankton Biology and Ecology, 51(2), 110-112, 20040801
  27. Prodajus curviabdominalis n. sp. (Isopoda: Epicaridea: Dajidae), an ectoparasite of mysids, with notes on morphological changes, behaviour and life-cycle, Systematic Parasitology, 60, 39-57, 20040601
  28. First record of an ectoparasitic dinoflagellate, Oodinium inlandicum (Dinophyta) infecting a chaetognath, Sagitta crassa from the Korean coasts, Algae, 19(3), 20040401
  29. Systematics and zoogeography of the deep-sea hyperbenthic family Arietellidae (Copepoda : Calanoida) collected from the Sulu Sea, JOURNAL OF NATURAL HISTORY, 39(27), 2483-2514, 2005
  30. Ectoparasitic isopod, Norileca indica (Crustacea, Isopoda, Cymothoidae), obtained from the stomach of Coryphaena hippurus (Perciformes, Coryphaenidae) in the Philippines, Biogeography, 7, 25-27, 20050820
  31. A new genus and species of nicothoid copepod (Crustacea : Copepoda : Siphonostomatoida) parasitic on the mysid Siriella okadai Ii from off Japan, SYSTEMATIC PARASITOLOGY, 62(1), 65-81, 2005
  32. A revision of the family Dissonidae Kurtz, 1924 (Copepoda : Siphonostomatoida), SYSTEMATIC PARASITOLOGY, 70(2), 81-106, 2008
  33. New record of a euphausiid ectoparasitic isopod, Heterophryxus appendiculatus G. O. Sars, 1885 (Crustacea: Dajidae) from Japan, PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON, 121(3), 326-330, 20081007
  34. Infection with the parasitic copepod Clavella parva (Lernaeopodidae) in gold-eye rockfish Sebastes thompsoni broodstock in Japan (with T. Umino, D. Uyeno, S. Ohtsuka, and H. Koizumi), Fish Pathology, 43(1), 55-60, 20080301
  35. Records of Caligus (Crustacea: Copepoda: Caligidae) from marine fish cultured in floating cages in Malaysia with a redescription of the male of Caligus longipedis Bassett-Smith, 1898, ZOOLOGICAL STUDIES, 48(6), 797-807, 20091101
  36. Complete life cycle of a pennellid Peniculus minuticaudae Shiino, 1956 (Copepoda: Siphonostomatoida) infecting cultured threadsail filefish, Stephanolepis cirrhifer, PARASITE, 20, 20131029
  37. Associations of fish juveniles with rhizostome jellyfishes in the Philippines, with taxonomic remarks on a commercially harvested species in Carigara Bay, Leyte Island, Plankton & Benthos Research, 9(1), 51-56, 201402
  38. Development of the swimming acorn worm Glandiceps hacksi: similarity to holothuroids, EVOLUTION & DEVELOPMENT, 16(3), 149-154, 201405
  39. Evolution of copepods-pattern and process, Aguabiology, 21(6), 463-470, 19990401
  40. A new species of Ridgewayia (Copepoda: Calanoida) from a submarine cave in Palau, western Pacific, Crustacean Research, 29, 1-11, 20000401
  41. Three new species of the demersal calanoid copepod Pseudocyclops from Phuket, Thailand, Species Diversity, 5, 201-213, 20000401
  42. Introduction of the Asian copepods Acartiella sinensis, Tortanus dextrilobatus (Copepoda: Calanoida), and Limnoithona teraspina (Copepoda: Cyclopoida) to the San Francisco estuary, California, USA, 1-16, 20000401
  43. Taxonomy, functional morphology, and behavioral ecology of the planktonic calanoid copepod Tortanus (Atortus), Journal of Natural Histroy, 34, 1967-1976, 20000401
  44. Second record of Cyclopina Kiraensis, a small brackish-water cyclopoid copepod, in Japan, Limnology, 2, 49-50, 20010401
  45. ★, Phylogenetic relationships between arietellid genera (Copepoda : Calanoida), with establishment of three new genera, Bulletin of the Natural History Museum, 60(2), 105-172, 19940401
  46. Pseudocyclops lakshmi, a new species (Pseudocyclpoidae: calanoida: Copepoda) from the Lccadives, India, Proceedings of Biological Society of Washington, 107, 151-163, 19940401
  47. New species of Synagoga (Crustacea: Ascothoracida) from plankton off Okinawa, Japan, with a SEM study of the carapace, Publications of the Seto Marine Biological Laboratory, 36, 293-311, 19950401
  48. SEM observation of the nauplius of Monstrilla hamatapex, new species, from Japan and an example of upgraded descriptive standards for monstrilloid copepods, Journal of Crustacean Biology, 15, 703-719, 19950401
  49. Monodisc strobilation in Japanese giant box jellyfish Morbakka virulenta (Kishinouye, 1910): a strong implication of phylogenetic similarity between Cubozoa and Scyphozoa, EVOLUTION & DEVELOPMENT, 17(4), 231-239, 2015
  50. A taxonomic study on the genus Anilocra (Isopoda : Cymothoidae) parasitic on fish collected from Japan, ZOOLOGICAL SCIENCE, 22(12), 1434-1434, 2005
  51. Accumulation of tetrodotoxin (TTX) in Pseudocaligus fugu, a parasitic copepod from panther puffer Takifugu pardalis, but without vertical transmission - Using an immunoenzymatic technique, TOXICON, 48(1), 116-122, 2006
  52. A new family of poecilostomatoid copepods (Umazuracolidae) based on specimens parasitic on the black scraper (Thamnaconus modestus) in Japan, ZOOLOGICAL SCIENCE, 23(5), 483-496, 2006
  53. Larvaceans and their houses as important food for some pelagic copepods, Bulletin of Plankton Society of Japan, 535-551, 19910401
  54. Relationship between mouthpart structures and in situ feeding habits of species of the family Pontellidae, Marine Biology, 111, 19910401
  55. ★, A new family of calanoid copepods, the Hyperbionycidae, collected from the deep-sea hyperbenthic community in the northeastern Atlantic), Sarsia, 78, 69-82, 19930401
  56. A new tantulocaridan (Crustacea: Maxillopoda) parasitic on calanoid, harpacticoid and cyclopoid copepods, Publications of Seto Marine Biological Laboratory, 36, 197-209, 19940401
  57. Tortanus derjugini Smirnov (Copepoda: Calanoida) from the Ariake Se, western Japan, with notes on the zoogeography of brackish-water calanoid copepods in East Asia, Bulletion of Plankton Society of Japan, 42, 147-162, 19950401
  58. Relationships between mouthpart structures and in situ feeding habits of five neritic calanoid copepods in teh Chukchi and norther Bering Seas in October 1988, Proceedings of the NIPR Symposium on Polar Biology, 9, 153-168, 19960401
  59. Specialized feeding mechanism in the pelagic copepod genus Heterorhabdus (Calanoida: Heterorhabdidae), with special reference to the mandibular tooth and labral glands, Marine Biology, 126, 619-632, 19960401
  60. Three new species of the demersal calanoid copepod Placocalanus (Ridgewayiidae) from Okinawa, southern Japan, Sarsia, 81, 247-263, 19960401
  61. In situ feeding habits of Oncaea (Copepoda: Poecilostomatoida) from the upper 250 m of the central Red Sea, with special reference to consumption of appendicularian houses, Bulletion of Plankton Society of Japan, 43, 89-105, 19960401
  62. Cyclopoid copepods from a stream in the limestone cave Akiyoshido, Japanese Journal of Limnology, 57, 305-312, 19960401
  63. Two new genera of Tantulocarida(Crustacea)infesting asellote isopods and siphonostomatid copepods from western Japan, Journal of Natural History, 32, 683-699, 19980401
  64. Description and female genital structures of a new species of the demersal calanoid copepod Ridgewayia from southern Japan, Natural Histroy Research, 5, 17-29, 19980401
  65. Xanthocalanus gracilis and Tharybis magna (Copepoda: Calanoida) rediscovered from the Antarctic Ocean with baited traps, Journal of Natural Histroy, 32, 683-699, 19980401
  66. Gaussia princeps (Scott) (Copepoda, Calanoida, Metridinidae) from the Indo-Pacific, with notes on teh zoogeography of the genus, Species Diversity, 3, 169-186, 19980401
  67. Platycopia compacta n. sp. , the second species of Platycopioida(Crustacea : Copepoda)in the Indo-Pacific region, with remarks on development, feeding, swimming, and zoogeography, Zoological Science, 15, 415-424, 19980401
  68. Evolutionary swithcing from suspension-feeding to carnivory in the calanoid family Heterorhabdidae (Copepoda), Journal of Natural Histroy, 32, 785-804, 19980401
  69. Ultrastructure of the moutpart sensory setae in mesopelagic copepods of the family Scolecitrichidae, Journal of Natural Histroy, 32, 1303-1318, 19980401
  70. Redescription and taxonomic status of Sinodiaptomus valkanovi, a common limnoplanktonic calanoid copepod in Japan, with comparison to the closely related S. sarsi, Hydrobiologia, 379, 159-168, 19980401
  71. Phylogeny and zoogeography of the planktonic copepod genusTortanus (Calanoida : Tortanidae), with establishment of a new subgenus and descriptions of two new species, Journal of Crustacean Biology, 18(4), 774-807, 19980401
  72. The phylogeny, zoogeography, and ecology of marine cavernicolous crustaceans, Taxa, 3-13, 19990401
  73. Phylogenetic relationships of the family Metridinidae(Copepoda : Calanoida), Journal of Fisheries Science and Technology, 2(2), 122-128, 19990401
  74. Redescription of Haloptilvs caribbeanensis(Copepoda : Calanoida) from the Pacific, with remarks on the morphology of antennules in the genus Haloptilus, Journal of Fisheries Science and Technology, 2(2), 129-134, 19990401
  75. A new deep-water calanoid copepod and the phylogeny of the genus Nullosetigera nom. nov. in the Nullosetigeridae nom. nov. (pro Phyllopus: Phyllopodidae) from Japanese waters, Plankton Biology and Ecology, 46, 128-131, 19990401
  76. Redescription of two diosaccid harpacticoid copepods from the northern Mariana Islands, 2, 129-134, 19990401
  77. Playtcopia compactan.sp., the second species of Platycopioida (Crustacea: Copepoda) in the Indo-Pacific region, with remarks on development, feeding, swimmimg, and zoogeography, Zoological Science, 6, 3-13, 19990401
  78. Redescription of Haloptilus caribbeanensis (Copepoda: Calanoida) from the Pacific, with remarks on the morphology of antennules in the genus Haloptilus, 2, 122-128, 19990401
  79. Two new genera of Tantulocarida (Crustacea) infesting asellote isopods and siphonostomatoid copepods from western Japan, Journal of Natural Histroy, 33, 1581-1602, 19990401
  80. Phylogeny and zoogeography of the planktonic copepod genus Tortanus (Calanoida: Tortanidae), with establishment of a new subgenus and descriptions of two new species, Journal of Crustacean Biology, 18, 774-807, 19990401
  81. Phylogenetic relationships of the family Metridinidae (Copepoda: Calanoida), Plankton Biology and Ecology, 46, 132-147, 19990401
  82. Abundance and in-situ feeding habits of Neocalanus cristatus(Copepoda : Calanoida)in the Central and Western North Pacific Ocean, Bulletin of the National Research Institute of Far Seas Fisheries, 37-52, 20010401
  83. New species of Tortanus(Copepoda ; Calanoida)from stomach contents of chum salmon juveniles collected from the Sea of Japan, Plankton Biology and Ecology, 48(1), 59-67, 20010401
  84. Two new families of copepods(Copepoda : Siphonostomatoida)parasitic on echinoderms, Journal of Crustacean Biology, 21(1), 96-105, 20010401
  85. Oodinium inlandicum sp. nov. (Blastodiniales, Dinophyta), a new ectoparasitic dinoflagellates infesting a chaetoganth Sagitta crassa, Hydrobiologia, 453/454, 441-466, 20010401
  86. The first record of two demersal calanoid copepods, Pseudodiaptomus poplesia and P. nihonkaiensis in Korea, with remarks on morphology of the genital area, Plankton Biology and Ecology, 48, 85-95, 20010401
  87. Two new families of copepods (Copepoda: Siphonostomatoida) parasitic on echinoderms, Hydrobiologia, 448, 203-215, 20010401
  88. New species of Tortanus (Copepoda; Calanoida) stomach contents of chum salmon juveniles collected from the Sea of Japan, Journal of Crustacean Biology, 21, 96-105, 20010401
  89. Second record of Cyclopina kiraensis, a small brackish-water cyclopoid copepod, in Japan, Plankton Biology and Ecology, 48, 59-67, 20010401
  90. A new genus and species of the family Mantridae (Copepoda: Cyclopoda) infesting the bivalve Pseudochama retroversa from the Seto Inland Sea, western Japan, Limnology, 2, 49-50, 20010401
  91. Ingolfiella inermis n. sp., a new intersitial ingolfellid amphipod from Okinawa, southern Japan, Crustaceana, 79(9), 1097-1105, 20061231
  92. Accumulation of tetrodotoxin (TTX) in Pseudocaligus fugu, a parasitic copepod from panther puffer Takifugu pardalis, but without vertical transmission-using an immunoenzymatic technique, Toxicon, 48, 116-122, 20060419
  93. ★, Sexual dimorphism in calanoid copepods: morphology and function, Hydrobiologia, 453/454, 441-466, 20010501
  94. Two new families of copepods (Copepoda : Siphonostomatoida) parasitic on echinoderms, JOURNAL OF CRUSTACEAN BIOLOGY, 21(1), 96-105, 2001
  95. The first record of two demersal calanoid copepods, Pseudodiaptomus poplesia and P-nihonkaiensis in Korea, with remarks on morphology of the genital area, HYDROBIOLOGIA, 448, 203-215, 2001
  96. Taxonomic studies on brackish copepods in Korean waters II. Ontogeny and phylogeny of appendages in copepodid stages of Tortanus derjugini Smirnov, 1935 (Copepoda, Calanoida), JOURNAL OF PLANKTON RESEARCH, 23(10), 1157-1169, 2001
  97. Sexual dimorphism in calanoid copepods: morphology and function, HYDROBIOLOGIA, 453, 441-466, 2001
  98. Three new species of the genus Macandrewella (Copepoda : Calanoida : Scolecitrichidae) from the Pacific Ocean, with notes on distribution and feeding habits, JOURNAL OF NATURAL HISTORY, 36(5), 531-564, 2002
  99. Redescription of two new species of Pseudodiaptomus from Asia and Australia (Crustacea: Copepoda: Calanoida: Pseudodiaptomidae) with discussion of the female genital structure and zoogeography of Indo-West Pacific species, Proceedings of the Biologucal Society of Washington, 115(3), 650-669, 20020401
  100. Functional morphology and food habits of deep-sea copepods of the genus Cephalophanes (Calanoida : Phaennidae): perception of bioluminescence as a strategy for food detection, MARINE ECOLOGY PROGRESS SERIES, 227, 157-171, 2002
  101. A new species of Thetispelecaris (Crustacea : Peracarida) from submarine cave on Grand Cayman Island, ZOOLOGICAL SCIENCE, 19(5), 611-624, 2002
  102. Three new species of the genus Macandrewella (Copepoda: Calanoida: Scolecitrichidae) from the Pacific Ocean, with notes on distribution and feedinh habits, Journal of Natural History, 36, 531-564, 20020401
  103. Functional morphology and food habits of deep-sea copepods of the genus Cephalophanes (Calanoida: Phaennidae): perception of bioluminescence as a strategy for food detection, Marine Ecology Progress Series, 227, 157-171, 20020401
  104. A new species of Thetispelecaris (Crustacea: Peracarida) from submarine cave on Grand Cayman Island, Zoological Science, 19, 611-624, 20020401
  105. Redescription of two species of Pseudodiaptomus from Asia and Australia (Crustacea : Copepoda : Calanoida : Pseudodiaptomidae) with discussion of the female genital structure and zoogeography of Indo-West Pacific species, PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON, 115(3), 650-669, 20021014
  106. Decapod crustaceans collected from the southern part of the Sea of Japan in 2000-2001 using TRV Toyoshio-maru, Natural Histroy Research, 7(1), 19-73, 20020401
  107. A new species of Tortanus (Atortus) (Copepoda: Calanoida: Tortanidae) from Rodriges Island, Mauriius, Journal of Marine Biological Association of United Kingdom, 83, 355-360, 20030401
  108. New record of Centropages brevifurcus (Crustacea: Copepoda: Calanoida) from the Gulf of Thailand and its full redescription, Species Diversity, 8, 67-78, 20030401
  109. Mating plug in the planktonic copepod Tortanus (Atortus) rubidus, Plankton Biology and Ecology, 50(1), 25-26, 20030401
  110. Occurrence of intersex individuals in the sergestid shrimp, Acetes sibogae, in Darwin Harbour, Northern Territory, Australia, CRUSTACEANA, 76, 749-754, 2003
  111. Intersex in the mysid Siriella japonica izuensis Ii: the possibility it is caused by infestation with parasites, Plankton Biology and Ecology, 50(2), 65-70, 20030801
  112. Occurrence of intersex individuals in the sergestid shrimp, Acetes sibogae, in Darwin harbour, Norhtern Territory, Australia, Crustaceana, 76(6), 749-754, 20030401
  113. Morphology and host-specificity of the apostome ciliate Vampyrophrya pelagica infecting pelagic copepods in the Seto Inland Sea, Japan, MARINE ECOLOGY PROGRESS SERIES, 282, 129-142, 2004
  114. Morphology and host-specificity of the apostome ciliate Vampyrophrya pelagica infecting pelagic copepods in the Seto Inland Sea, Japan, Marine Ecology Progress Series, 282, 129-142, 20040401
  115. The identity of Limnoncaea diuncata Kokubo, 1914 (Copepoda: Poecilostomatoida) from Hokkaido, Japan, with the relegation of Diergasilus Do, 1981 to a junior synonym of Thersitian Norman, 1905, Systematic Parasitology, 57, 35-44, 20040401
  116. Redescription and taxonomic remarks of the licomolgid copepod Paraphiloconcha meretricis (Crustacea: Copepoda: Poecilostomatoida) parasitic on the bivalve Meretrix lamarckii from Japan, Species Diversity, 9, 331-341, 20040401
  117. ★, Morphology and host-specificity of the apostome ciliate Vampyrophrya pelagica infecting pelagic copepods in the Seto Inland Sea, Japan, Marine Ecology Progress Series, 282, 129-142, 20041116
  118. Review of parasites of marine zooplankton, Bulletin of Plankton Socicty of Japan, 47(1), 1-16, 20000401
  119. Description of two new species of Neotachidius Shen & Tai, 1963 (Copepoda, Harpacticoida, Tachidiidae) from Korean brackish waters and proposal of a new genus for Tachidius (Tachidius) vicinospinalis Shen & Tai, 1964, ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, 143(1), 133-159, 2005
  120. Systematics and zoogeography of the deep^sea hyperbenthic family Arietellidae (Copepoda: Calanoida) collected from the Sulu Sea, Journal of Natural History, 39(27), 2483-2514, 20050630
  121. A new genus and species of nicothoid copepod (Crustacea: Copepoda: Siphonostomatoida) parasitic on the mysid Siriella oakdai Ii from off Japan, Systematic Parasitology, 62, 65-81, 20050501
  122. A new species of the calanoid copepod genus Centropages (Crustaea) collected from Shimizu Port, Middle Japan: introduced or not?, Plankton Biology and Ecology, 52(2), 92-99, 20050801
  123. A new species of Tortanus (Atortus) (Copepoda: Calanoida: Tortanidae) from the Seychelles, Mauritius and Madagascar, Journal of the Marine Biological Association of UK, 85, 65-70, 20050301
  124. Prodajus curviabdominalis n. sp (Isopoda : Epicaridea : Dajidae), an ectoparasite of mysids, with notes on morphological changes, behaviour and life-cycle, SYSTEMATIC PARASITOLOGY, 60(1), 39-57, 2005
  125. A new species of Tortanus (Atortus) (Copepoda : Calanoida : Tortanidae) from the Seychelles, Mauritius and Madagascar, JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM, 85(1), 65-70, 2005
  126. Description of two new species of Neotachidius Shen & Tai, 1963 (Copepoda, Harpacticoida, Tachidiidae) from Korean brackish waters and proposal of a new genus for Tachidius (Tachidius) vicinospinalis Shen & Tai, 1964, Zoological Journal of the Linnean Society, 143, 133-159, 20050801
  127. Three new species of deep-sea hyperbenthic aetideid copepods (Crustacea) collected from Nansei Islands, southwestern Japan, National Science Museum Monograph, 29, 225-247, 20050401
  128. A new species of Pseudodiaptomus (Crustacea : Copepoda : Calanoida) from the Philippines, with a key to pseudodiaptomids from the Philippines and comments on the status of the genus Schmackeria, PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON, 119(2), 202-221, 20060711
  129. A new family of poecilostomatoid copepods (Umazuracolidae) based on specimens parasitic on the black scraper (Thamnaconus modestus) in Japan, Zoological Science, 23, 483-496, 20060531
  130. A new species of Pseudodiaptomus (Crustacea: Copepoda: Calanoida) from the Philippines, with a key to pseudodiaptomidsfrom the Philippines and comments on the status of the genus Schmackeria, Proceedings of the Biological Society of Washington, 119(2), 202-221, 20060611
  131. Accumulation of tetrodotoxin (TTX) in Pseudocaligus fugu, a parasitic copepod from panther puffer Takifugu pardalis, but without vertical transmission - Using an immunoenzymatic technique, TOXICON, 48(1), 116-122, 2006
  132. A new family of poecilostomatoid copepods (Umazuracolidae) based on specimens parasitic on the black scraper (Thamnaconus modestus) in Japan, ZOOLOGICAL SCIENCE, 23(5), 483-496, 2006
  133. Ingolfiella inermis n. sp., a new interstitial ingolfiellid amphipod from Okinawa, southern Japan (Peracarida, Amphipoda), CRUSTACEANA, 79, 1097-1105, 2006
  134. Detection of tetrodotoxin (TTX) from two copepods infecting the grass puffer Takifugu niphobles: TTX attracting the parasites?, Toxicon, 48, 620-626, 20060620
  135. ★, Species of the parasitic genus Duboscquella are members of the enigmatic Marine Alveolate Group I, Protist, 158, 337-347, 20070613
  136. Isolation and characterization of bacteria from the copepod Pseudocaligus fugu ectoparasitic on the panther puffer Takifugu pardalis wth the emphasis on TTX, Toxicon, 50, 779-790, 20070705
  137. Symbionts of plankters: their diversity and importance, Journal of Scientific Research Chulalongkorn University, 2550, 29-42, 20071201
  138. Vertical distribution and feeding ecology of a copepod Gaetanus variabilis in the southern Japan Sea during winter, La mer, 45, 47-58, 20071001
  139. Prevalence and intensity of Phrixocephalus umbellatus (Copepoda: Siphonostomatoida: Pennellidae) parasitic on Paralichthys olivaceus in the western part of the Sea of Japan, Fishries Science, 73, 214-216, 20071001
  140. Species of the parasitic genus Duboscquella are members of the enigmatic Marine Alveolate Group I, PROTIST, 158(3), 337-347, 2007
  141. Temporal partitioning: dynamics of alternating occupancy of a host microhabitat by two different crustacean parasites, Marine Ecology Progress Series, IN PRESS, 20071201
  142. Prevalence and intensity of Phrixocephalus umbellatus (Copepoda : Siphonostomatoida : Pennellidae) parasitic on Paralichthys olivaceus in the western part of the Sea of Japan, FISHERIES SCIENCE, 73(1), 214-216, 2007
  143. Prevalence, intensity and reproduction of copepods parasitic on temperate bass Lateolabyax japonicas collected from Ariake Sea, NIPPON SUISAN GAKKAISHI, 73(4), 693-702, 2007
  144. Isolation and characterization of bacteria from the copepod Pseudocaligus fugu ectoparasitic on the panther puffer Takifugu pardalis with the emphasis on TTX, TOXICON, 50(6), 779-790, 2007
  145. Temporal partitioning: dynamics of alternating occupancy of a host microhabitat by two different crustacean parasites, MARINE ECOLOGY PROGRESS SERIES, 348, 261-272, 2007
  146. A new species of Thysanote Kroyer, 1863 (Copepoda : Siphonostomatoida : Lernaeopodidae), a fish parasite from Thailand, ACTA ICHTHYOLOGICA ET PISCATORIA, 38(1), 29-35, 2008
  147. A new genus of monstrilloid copepods (Crustacea) with anteriorly pointing ovigerous spines and related adaptations for subthoracic brooding, ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, 152(3), 459-506, 2008
  148. Redescription of a subterranean amphipod, Pseudocrangonyx shikokunis (Crustacea: Amphipoda: Pseudocrangonyctidae) from Japan, Species Diversity, 13, 275-286, 20080827
  149. A new species of Anuretes Heller, 1865 (Copepoda : Caligidae) from the yellowbanded sweetlips Plectorhinchus lineatus (Haemulidae) off New Caledonia, SYSTEMATIC PARASITOLOGY, 70(1), 35-40, 2008
  150. Homogeneity among Lactococcus garvieae isolates from striped jack, Pseudocaranx dentex (Bloch & Schneider), and its ectoparasites, JOURNAL OF FISH DISEASES, 32(10), 901-905, 2009
  151. Records of Caligus (Crustacea: Copepoda: Caligidae) from Marine Fish Cultured in Floating Cages in Malaysia with a Redescription of the Male of Caligus longipedis Bassett-Smith, 1898, ZOOLOGICAL STUDIES, 48(6), 797-807, 2009
  152. A New Genus of Endoparasitic Copepods (Cyclopoida: Enterognathidae), Forming a Gall in the Calyx of Deep-sea Crinoids, ZOOLOGICAL SCIENCE, 27(8), 689-696, 2010
  153. Cladistic analysis of the calanoid Copepoda, INVERTEBRATE SYSTEMATICS, 24(3), 291-321, 2010
  154. Yaku'amides A and B, Cytotoxic Linear Peptides Rich in Dehydroamino Acids from the Marine Sponge Ceratopsion sp., JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 132(50), 17692-17694, 20101222
  155. A New Species of Paramacrochiron (Copepoda: Cyclopoida: Macrochironidae) Associated with the Rhizostome Medusa Rhopilema hispidum Collected from the Gulf of Thailand, with a Phylogenetic Analysis of the Family Macrochironidae, ZOOLOGICAL SCIENCE, 29(2), 127-133, 2012
  156. Evolution of the bomolochiform superfamily complex (Copepoda: Cyclopoida): New insights from ssrDNA and morphology, and origin of umazuracolids from polychaete-infesting ancestors rejected, INTERNATIONAL JOURNAL FOR PARASITOLOGY, 42(1), 71-92, 2012
  157. Biology of the Swimming Acorn Worm Glandiceps hacksi from the Seto Inland Sea of Japan, ZOOLOGICAL SCIENCE, 29(5), 305-310, 2012
  158. A new species of Enterognathus (Copepoda, Cyclopoida, Enterognathidae) collected from the Seto Inland Sea, western Japan, ZOOKEYS, 1-8, 2012
  159. Isolation of Spirastrellolides A and B from a Marine Sponge Epipolasis sp and Their Cytotoxic Activities, JOURNAL OF NATURAL PRODUCTS, 75(6), 1192-1195, 2012
  160. The lunule of caligid copepods: an evolutionarily novel structure, EVOLUTION & DEVELOPMENT, 14(6), 465-475, 2012
  161. Seasonal Occurrence and Microhabitat of the Hyperparasitic Monogenean Udonella fugu on the Caligid Copepod Pseudocaligus fugu Infecting the Grass Puffer Takifugu niphobles in the Seto Inland Sea, Japan, OCEAN SCIENCE JOURNAL, 47(3), 181-187, 2012
  162. Redescription of Pseudacanthocanthopsis secunda (Yamaguti and Yamasu, 1960) (Copepoda: Chondracanthidae) parasitic on marine fishes from the Seto Inland Sea, Japan and the East China Sea off Japan and Korea, JOURNAL OF NATURAL HISTORY, 47, 553-562, 20130301
  163. The caligid life cycle: new evidence from Lepeophtheirus elegans reconciles the cycles of Caligus and Lepeophtheirus (Copepoda: Caligidae), PARASITE, 20, 20130507
  164. A new species of Pseudodiaptomus (Crustacea, Copepoda, Calanoida, Pseudodiaptomidae) from the Prasae River Estuary, Gulf of Thailand, ZOOKEYS, 39-54, 2013
  165. Reconstruction of Arietellid Copepod Phylogenetic Relationship, with Description of a New Species of Sarsarietellus (Copepoda, Calanoida, Arietellidae) from Korean Waters, ZOOLOGICAL SCIENCE, 30(11), 998-1004, 2013
  166. A new species of Labidocera (Copepoda, Calanoida, Pontellidae) collected from Okinawa, southwestern Japan, with establishment of five Indo-West Pacific species groups in the L. detruncata species complex, ZOOKEYS, 21-34, 20141016
  167. A new species of Gastrosaccus Norman, 1868 (Mysida, Mysidae, Gastrosaccinae) from a sandy shore of Indonesia, ZOOKEYS, 17-32, 20140901
  168. First Record of Association of Copepods with Highly Venomous Box Jellyfish Chironex, with Description of New Species of Paramacrochiron (Cyclopoida: Macrochironidae), ZOOLOGICAL SCIENCE, 32(2), 195-203, 201503
  169. A new species of the commercially harvested jellyfish Crambionella (Scyphozoa) from central Java, Indonesia with remarks on the fisheries, JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM, 95(3), 471-481, 201505
  170. Screening of candidate genes encoding proteins expressed in pectoral fins of fugu Takifugu rubripes, in relation to habitat site of parasitic copepod Caligus fugu, using suppression subtractive hybridization, FISH & SHELLFISH IMMUNOLOGY, 44(1), 356-364, 201505
  171. Prevalence and intensity of Phrixocephalus umbellatus (Copepoda : Siphonostomatoida : Pennellidae) parasitic on Paralichthys olivaceus in the western part of the Sea of Japan, FISHERIES SCIENCE, 73(1), 214-216, 2007
  172. Temporal partitioning: dynamics of alternating occupancy of a host microhabitat by two different crustacean parasites, MARINE ECOLOGY PROGRESS SERIES, 348, 261-272, 2007
  173. CYPRIS Y FROM THE NORTH PACIFIC (CRUSTACEA : MAXILLOPODA), PUBLICATIONS OF THE SETO MARINE BIOLOGICAL LABORATORY, 29(1), 179-186, 19840331
  174. Records of Caligus (Crustacea: Copepoda: Caligidae) from Marine Fish Cultured in Floating Cages in Malaysia with a Redescription of the Male of Caligus longipedis Bassett-Smith, 1898, ZOOLOGICAL STUDIES, 48(6), 797-807, 2009
  175. Infection with the Parasitic Copepod Clavella parva (Lernaeopodidae) in Gold-eye Rockfish Sebastes thompsoni Broodstock in Japan, FISH PATHOLOGY, 43(1), 55-60, 2008
  176. Review of parasites of marine zooplankton, Bulletin of the Plankton Society of Japan, 47(1), 1-16, 20000225
  177. Cyclopoid Copepods from a Stream in the Limestone Cave Akiyoshido, Japanese journal of limnology, 57(4), 305-312, 19961228
  178. Reconsideration on Feeding Habits of Marine Pelagic Copepods (Crustacea), Umi no Kenkyu (Oceanography in Japan), 6(5), 299-320, 19971005
  179. Three new species of the demersal calanoid copepod Pseudocyclops from Phuket, Thailand, Plankton Biology and Ecology, 46(2), 132-147, 19990801
  180. Calanoid Copepods Collected from the Near-bottom in Tanabe Bay on the Pacific Coast of the Middle Honshu, Japan. III. Stephidae, PUBLICATIONS OF THE SETO MARINE BIOLOGICAL LABORATORY, 32(4), 219-232, 19871226
  181. Calanoid Copepods Collected from the Near-bottom in Tanabe Bay on the Pacific Coast of the Middle Honshu, Japan. II. Arietellidae (cont.), PUBLICATIONS OF THE SETO MARINE BIOLOGICAL LABORATORY, 30(4), 287-306, 19851225
  182. A Note on the Feeding Habit of a Calanoid Copepod, Pontellopsis yamadae Mori, PUBLICATIONS OF THE SETO MARINE BIOLOGICAL LABORATORY, 30(1), 145-149, 19850630
  183. A New Tantulocaridan (Crustacea : Maxillopoda) Parasitic on Calanoid, Harpacticoid and Cyclopoid Copepods, PUBLICATIONS OF THE SETO MARINE BIOLOGICAL LABORATORY, 36(4), 197-209, 19941115
  184. Seasonal changes in infection with trematode species utilizing jellyfish as hosts: evidence of transmission to definitive host fish via medusivory, PARASITE, 23, 20160407
  185. Molecular evidence on evolutionary switching from particle-feeding to sophisticated carnivory in the calanoid copepod family Heterorhabdidae: drastic and rapid changes in functions of homologues, JOURNAL OF NATURAL HISTORY, 50(27-28), 1759-1772, 20160324
  186. Cytotoxic liner acetylenes from a marine sponge Pleroma sp., Tetrahedron, 71, 9564-9579, 20151024
  187. Historical biogeography of the genus Ploycopissa (Ostracod: Myodocopa: Cladocopina), with the description and DNA barcode of the second Indo-Pacific species from the Seto Inland Sea, Marine Biodiversity, 20151118
  188. Supplementary description of three Acartiella species (Crustacea;: Copepoda: Calanoida) from estuarine waters in Thailand, Species Diversity, 20, 167-181, 20151125
  189. ★, Molecular identification of "Gum Gum": a food mole crab Hippa adactyla from Papua New Guinea, Biosphere Science, 201512
  190. Historical biogeography of the genus Polycopissa (Ostracoda: Myodocopa: Cladocopina), with the description and DNA barcode of the second Indo-Pacific species from the Seto Inland Sea, MARINE BIODIVERSITY, 46(3), 625-640, 2016
  191. Yakushinamides, Polyoxygenated Fatty Acid Amides That Inhibit HDACs and SIRTs, from the Marine Sponge Theonella swinhoei, JOURNAL OF NATURAL PRODUCTS, 79(9), 2384-2390, 2016
  192. New records of Caligidae (Copepoda, Siphonostomatoida) from the Philippines, ZOOTAXA, 4174(1), 237-248, 20161011
  193. On the occurrence of caligids (Copepoda: Siphonostomatoida) in the marine plankton: a review and checklist, ZOOTAXA, 4174(1), 437-447, 20161011
  194. A New Species of Hyperbenthic Cyclopoid Copepod from Japan: First Record of the Genus Cyclopicina in the Indo-Pacific Region, ZOOLOGICAL SCIENCE, 33(6), 659-666, 201612
  195. SEVEN NEW SPECIES OF TORTANUS (ATORTUS) (COPEPODA, CALANOIDA, TORTANIDAE) FROM NORTH SULAWESI, INDONESIA, CRUSTACEANA, 90(1), 77-99, 201701
  196. Magnetic light cloaking control in the marine planktonic copepod Sapphirina, AIP ADVANCES, 7(5), 201703
  197. Modulation of light localization in the iridophores of the deep-sea highlight hatchetfish Sternoptyx pseudobscura under magnetic field, AIP ADVANCES, 7(5), 201701
  198. Possible westward extension of submerged Oyashio waters to off Tanegashima Island, Kyushu, western Japan: based on the occurrence of the subarctic copepod Neocalanus crostatas, Biosphere Science, 25-30, 201612
  199. Low genetic diversity in Ozobranchus janteseanus (Hirudinida: Ozobranchidae) in Japan: possibility of introduction with their host turtles, Parasitology International, 66, 798-801, 20170826
  200. Structure Revision of Poecillastrin C and the Absolute Configuration of the beta-Hydroxyaspartic Acid Residue, ORGANIC LETTERS, 19(19), 5395-5397, 20171006
  201. New records of six deep-sea caridean shrimps (Crustacea: Decapoda) from the Ryukyu Islands and its adjacent waters, southwestern Japan, ZOOTAXA, 4457(1), 114-128, 20180807
  202. A new species of Peniculus (Copepoda: Siphonostomatoida) parasitizing mesopelagic myctophid fish: first discovery of colonization of the genus in deep water, PARASITE, 25, 20181126
  203. A new species of Acartia (Copepoda, Calanoida) from the Philippines, based on morphological and molecular analyses, ZOOKEYS, 71-94, 20190108
  204. Benthic platyctenid ctenophore, Vallicula multiformis Rankin, 1956, found in an aquarium on Palawan Island, the Philippines, PLANKTON & BENTHOS RESEARCH, 14(1), 14-21, 201902
  205. Toxicity and Toxin Composition of the Greater Blue-Ringed Octopus Hapalochlaena lunulata from Ishigaki Island, Okinawa Prefecture, Japan, TOXINS, 11(5), 201905
  206. Diel patterns of Zooplankton community structure in nearshore waters of different substrates off Tinggi and Sibu Islands, Malaysia, with special reference to Copepods, AQUATIC ECOSYSTEM HEALTH & MANAGEMENT, 22(1), 86-102, 20190102
  207. Density of juveniles of trials-spined horseshoe crab Trachypleus tridentatus and characteristics of sediments in the Sone Estuary, Fukuoka, Japan, 16, 6-12, 201810
  208. Biological notes on Tachypleus tridentatus (Leach, 1819) in Hiroshima Prefecture, Japan: two species of epizootic organisms found on adults, and the carcass of a juvenile presumably eaten by a bird, 16, 1-5, 201810
  209. Epibionts on parasitic copepods infesting fish: unique substrates, Taxa, 201810
  210. Planktonic phases in symbiotic copepods: a review, Bulletin of Southern California Academy of Sciences, 117(2), 104-119, 201806
  211. Some observations of morphology and behavior of a hyperbenthic misophrioid copepod, Bulletin of Southern California Academy of Sciences, 117(2), 127-137, 201806
  212. A NEW SPECIES OF PARAMACROCHIRON (COPEPODA, CYCLOPOIDA) PARASITIC ON THE RHIZOSTOME MEDUSA VERSURIGA ANADYONEME (MAAS, 1903) COLLECTED FROM VIETNAM, CRUSTACEANA, 93(1), 111-123, 202002
  213. A new species of the genus Rhachotropis from off Amamioshima Island, northwestern Pacific (Crustacea: Amphipoda: Eusiridae), ZOOTAXA, 4750(2), 182-190, 20200311
  214. Microsclerodermins N and O, cytotoxic cyclic peptides containing a p-ethoxyphenyl moiety from a deep-sea marine sponge Pachastrella sp., TETRAHEDRON, 76(10), 20200306
  215. Pontopolycope orientalis sp. nov. (Crustacea: Ostracoda: Polycopidae), the First Report of a Living Species of the Genus from the Indo-Pacific Region, ZOOLOGICAL STUDIES, 59, 20200420
  216. A new species of Brachiella (Copepoda, Siphonostomatoida, Lernaeopodidae) from Peninsular Malaysia, with relegation of two genera Charopinopsis and Eobrachiella to junior synonyms of Brachiella, PARASITE, 27, 20200528
  217. Evolutionary Modification of Pereopods in Phronimid Amphipods (Crustacea: Amphipoda: Hyperiidea: Phronimidae) Reflects Host Differences, BIOLOGICAL BULLETIN, 238(3), 167-179, 20200601
  218. New genus and species of calanoid copepods (Crustacea) belonging to the group of Bradfordian families collected from the hyperbenthic layers off Japan, ZOOKEYS, 21-35, 20200722
  219. Differences in the cnidomes and toxicities of the oral arms of two commercially harvested rhizostome jellyfish species in Thailand, JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM, 100(5), 701-711, 202008
  220. A new genus and species of Loricifera (Nanaloricida: Pliciloricidae) from the deep waters of Japan, MARINE BIODIVERSITY, 50(6), 20201114
  221. Redescription of the freshwater calanoid copepod Neutrodiaptomus formosus with key to females of diaptomid species in Japan, PLANKTON & BENTHOS RESEARCH, 15(2), 178-184, 202005
  222. A new species in the subgenus Javanisomysis in the genus Anisomysis (Crustacea: Mysida: Mysidae) for specimens collected from Lombok Island, Indonesia, PLANKTON & BENTHOS RESEARCH, 15(3), 238-249, 202007
  223. Antiparasitic potential of Nephrolepis biserrata methanol extract against the parasitic leech Zeylanicobdella arugamensis (Hirudinea) and LC-QTOF analysis, SCIENTIFIC REPORTS, 10(1), 20201216
  224. Discovery of the fish host of the 'planktonic' caligid Caligus undulatus Shen & Li, 1959 (Crustacea: Copepoda: Siphonostomatoida), BIODIVERSITY DATA JOURNAL, 8, 20200608
  225. Ecological study of three hydrozoan species associated with three different nassariid gastropod species in the Seto Inland Sea, Bulletin of the Hiroshima University Museum, 12, 47-56
  226. A new species of Pilarella (Copepoda, Calanoida, Arietellidae) from the hyperbenthic layer of Japan, with a molecular phylogenetic analysis of some representative genera of the Arietellidae, ZOOKEYS, 179-194, 20210519
  227. The cephalothoracic sucker of sea lice (Crustacea: Copepoda: Caligidae): The functional importance of cuticular membrane ultrastructure, ARTHROPOD STRUCTURE & DEVELOPMENT, 62, 1-24, 202105
  228. Evidence for Host Jumping and Diversification of Marine Cephaloidophorid Gregarines (Apicomplexa) Between Two Distantly Related Animals, viz., Crustaceans and Salps, PROTIST, 172(4), 1-17, 202108
  229. DNA Metabarcoding Revealed Interspecific Dietary Difference and Prey Selectivity in Juvenile Horseshoe Crabs Carcinoscorpius rotundicauda and Tachypleus tridentatus From Hong Kong, FRONTIERS IN MARINE SCIENCE, 8, 1-11, 20211014
  230. Genetic diversities of commercially harvested jellyfish, Rhopilema hispidum and Lobonemoides robustus in, Southeast Asia, PLANKTON & BENTHOS RESEARCH, 16(4), 308-317, 202111
  231. Evidence of accumulation of tetrodotoxin (TTX) in tissues and body parts of ectoparasitic copepods via their feeding on mucus of TTX-bearing pufferfish, TOXICON, 204, 37-43, 202112

Publications such as books

  1. 2016, Diversity and Commonality in Animals Species Diversity of Animals in Japan, Recent advances in our understanding of the biodiversity of copepods in Japanese waters are briefly reviewed. It is noteworthy that the two new species of Platycopioida found in Japan are the first record of this order from the Indo-Pacific. Taxonomic revisions of calanoids in Japanese waters have continued based on both morphological and molecular data. Molecular analyses have revealed the presence of cryptic/sibling species in a common species and of intraspecific variations. Complete mitochondrial DNA sequences from copepods have been analyzed for Tigriopus japonicus, which suggest that copepods are genetically ‘eccentric.’ Molecular tools have helped to clarify the phylogenetic relationships of highly modified symbiotic copepods. Population dynamics, life cycles, and distributions of planktonic copepods have been thoroughly investigated in coastal and oceanic waters. These studies highlighted the influence of the Oyashio/Kuroshio currents on the coast, the high mortality of eggs from predation, adaptive responses to phytoplankton blooms, and niche partitioning by habitat and food. Deep-sea calanoids are highly diverse and specialized for detritivory and carnivory. East Asian planktonic copepods have been introduced to America and Europe via ballast water, although Japan not yet received any alien planktonic copepods. In contrast, parasitic copepods have been introduced to Japan via aquaculture. The life cycle of commercially important sea lice was clarified. Because copepods are one of the most abundant metazoans on Earth, more biological but also biomimetic information should be accumulated., Copepod Biodiversity in Japan: Recent advances in Japanese Copepodology, Alien • Copepod • Indo-West Pacific • Partition • Relict •Zoogeography, Springer, 2016, December, Scholarly Book, Joint work, E, Susumu Otsuka, Shuhei Nishida, 721
  2. 2015/10/08, Marine Protists Diversity and Dynamics, marine protists, Springer, 2015, 10, Scholarly Book, Cocompilation, E, Ohtsuka S, Suzaki T, Horiguchi T, Suzuki N, Not F (eds), 978-4-431-55129-4, 648
  3. 1999, Xth JSPS/VCC joint seminar on marine and fisheries sciences, Malacca, Malaysia (Taxonomy and feeding ecology of demersal calanoid copepods collected from Thailand, JSPS/VCC, 1999, Joint work

Invited Lecture, Oral Presentation, Poster Presentation

  1. An account on all copepodid stages of Paramacrochiron tridentatum Ohtsuka, Ha & Thu 2020 (Copepoda: Cyclopoida: Macrochironidae) associated with the rhizostome jellyfish Versurigaana dyoneme with notes on its affinity to the lichomolgoid complex, Yusuke Kondo, Sota Komeda, Susumu Ohtsuka, Panakkool Thamban Aneesh, Tran Manh Ha, Pham The Thu, Sho Toshino, Akane Iida & Jun Nishikawa, Tran Manh Ha, Pham The Thu, Sho Toshino, Akane Iida & Jun Nishikawa, e-International Conference on Copepoda, 2022/07/29, Without Invitation, English, World Association of Copepodologists, Online, The cyclopoid family Macrochironidae has been known to be associated with a variety of invertebrates such as cnidarians, echinoderms and tunicates. The species of the macrochironid genus Paramacrochiron is known to prefer jellyfish, as its host and it has been frequently collected from plankton samples. The genus globally includes 10 species described from the coastal areas of Japan, Southeast Asia, Australia, and India. In the present study, we are describing all the all post-naupliar stages of Paramacrochiron tridentatum Ohtsuka, Ha & Thu, 2020, a species recently described from the rhizostome jellyfish Versurigaana dyoneme obtained from Vietnam. The post-naupliar stages of P. tridentatum were collected from the same host and consisted of six copepodid stages as other copepods generally have. Interestingly, the present study appears to be the first detailed information on all the six copepodid stages of the family Macrochironidae. Further the information on sexual dimorphism and relationships between the Macrochironidae and lichomolgoid complex is also discussed. Sexual dimorphism first appeared in the maxillipeds of copepodid IV. The setation on the antennulary proximal segments and an element on the mandible in copepodid I of P. tridentatum imply close relationships between the Macrochironidae and Rhynchomolgidae.
  2. Seasonal fluctuations in the occurrence of two species of sea lice (Crustacea: Copepoda: Caligidae), Caligus sclerotinosus, and Lepeophtheirus sekii on wild red seabream Pagrus major in the Seto Inland Sea, Japan, Yusuke Nishida, Susumu Ohtsuka, Yusuke Kondo, Sadaharu Iwasaki, e-International Conference on Copepoda, 2022/07/29, Without Invitation, English, World Association of Copepodologists, Online, The parasitic copepods of the family Caligidae, commonly the sea lice, are known to infest many farmed fishes and may cause serious economic losses. In the present study, we discuss the seasonal occurrence of two caligid species on red sea bream Pagrus major collected from the Seto Inland Sea, Japan. The species, Caligus sclerotinosus Roubal, Armitage & Rhode, 1983 was originally described from silver sea bream Pagrus auratus, a fish native to Oceania. In Japan, C. sclerotinosus was first recorded from P. major cultured in Oita Prefecture, in 1999. This species is believed to have been introduced from Oceania to Japan through the international trade of P. auratus. Previous reports showed that heavy infestations of C. sclerotinosus were seen in farmed P. major in Japan and Korea. However, C. sclerotinosus had never been found in wild individuals of P. major. In the present study, we examined 284 wild individuals of P. major collected from the Seto Inland Sea from March 2020 to May 2021. Interestingly, we confirmed the presence of C. sclerotinosus in wild individuals of P. major in the sea for the first time. The prevalence and mean intensity of the species on wild P. major were 41.2% and 2.64 ± 2.3, respectively (highest record: 82.4% in September 2020 and 6.67 ± 3.21 in August 2020). Our results indicate that C. sclerotinosus has already spread over wild P. major entirely in the sea. Apart from C. sclerotinosus, we recovered another caligid Lepeophtheirus sekii Yamaguti, 1936 from the body surface of wild P. major. Prevalence and mean intensity of L. sekii were 43.3% and 2.57 ± 2.1, respectively (highest record: 78.4% in May 2021 and 4.25 ± 4.57 in May 2020). It seems that these two sea lice clearly exhibited seasonal segregation on the same host.
  3. Exploring evolutionary trends within the Pennellidae (Copepoda: Siphonostomatoida) using molecular data., Nanami Yumura, Kenta Adachi, Masato Nitta, Yusuke Kondo, Sota Komeda, Kaori Wakabayashi, Jun Fukuchi, Geoffrey A. Boxshall & Susumu Ohtsuka, Jun Fukuchi & Geoffrey A. Boxshall, e-International Conference on Copepoda, Without Invitation, English, World Association of Copepodologists, Online, Some species of the family Pennellidae have a profound impact on their fish hosts. This family consists of ecto or mesoparasitic copepods that parasitize marine fish. Since members of the family have highly modified bodies and reduced appendages, it is difficult to deduce their exact phylogenetic relationships. The present study aimed to reveal molecular phylogenetic relationships among 8 genera and 13 species of pennellids using 18S and 28S ribosomal DNA sequences. According to our analysis, three clades were generated (Clade-I, Peniculus-Peniculisa; Clade-II, Haemobaphes-Lernaeocera-Phrixocephalus-Exopenna-Lernaeenicus radiatus; Clade-III, Pennella-Lernaeenicus spp.), which were supported by high bootstrap values (> 82%) in Maximum likelihood and posterior probabilities (=1.00) in Bayesian inference. This result supports the morphology-based phylogenetic relationships previously proposed by Boxshall (1986) but did not support a sister group comprising Exopenna, Phrixocephalus, and Pennella. The first offshoot, Peniculus and Peniculisa, is defined as a fin-ectoparasite branch with members exhibiting clear tagmosis. The second and third branches to diverge are characterized by modifications of the anterior and posterior body tagmata to play roles in nutrient absorption/attachment and reproduction, respectively. Most of the species classified within Clade-II are gill parasites that have coiled egg strings that could have evolved in adaptation to the confined spaces within the gill cavities of the host. Phrixocephalus is an eye parasite in Clade-II, which also has coiled egg strings and may have descended from ancestral gill mesoparasites. All species of Clade-III are distinctly characterized by a head region that serves as the anchor, with processes that embed deeply in the host tissues.
  4. New discoveries on the development, life cycle and attachment mechanism of Caligus, Susumu Ohtsuka, Yusuke Nishida, Yusuke Kondo, Danny Tang & Geoffrey A. Boxshall, Danny Tang & Geoffrey A. Boxshall, e-International Conference on Copepoda, 2022/07/26, With Invitation, Japanese, World Association of Copepodologists, Online, The siphonostome genus Caligus Müller, 1785 has been studied intensively, in part because some species cause economic losses of commercially important farmed fishes. Basic data on the biology of caligids are essential to marine aquaculture. In this presentation, we briefly review our new findings concerning the development, life cycle, and attachment mechanism of Caligus occurring in Japan. We have elucidated the development and life cycle of two species: “planktonic” C. undulatus and non-indigenous C. sclerotinosus. The latter is considered to have been introduced from Oceania to Japan. Both species have the same number of developmental stages as in previously known congeners, i.e., 2 naupliar, 1 copepodid, 4 chalimus and the adult stages. We found that all post-naupliar stages of C. undulatus parasitize two species of brackish-water fishes, Sardinella zunasi and Konosirus punctatus. Detachment of the adult from its host to become a member of the plankton community may serve to prevent the release of free swimming naupliar stages in the lowest salinity zones where they would be vulnerable to freshwater. The pelagic mode of life has been independently adopted by members of different species groups within Caligus. Although the involvement of intermediate hosts for C. sclerotinosus has been suggested based on the highly skewed composition of developmental stages (towards the adults) on red sea bream Pagrus major, all post-naupliar stages were found to infect this host in the present study. The reported bias is likely a result of one or a combination of the following factors: (1) the rapid growth rates of chalimi, (2) the longevity of adults, and (3) the limited breeding season. Our discovery of C. sclerotinosus on wild hosts from the Seto Inland Sea, Japan sheds light on the rapid dispersal of this non-indigenous caligid after its introduction. We also report on an undescribed species of Caligus which was found to parasitize the small-sized, anadromous ice goby Leucopsarion petersii (which has only a 1-year life span). Attachment of caligids to host fishes by the main cephalothoracic sucker, assisted by the lunules in Caligus, is critical to their parasitic life. We have found considerable variation in internal cuticular structures (the endocuticle in particular), in different parts of the body of Caligus. The conversion of water flow resulting from simple antero-posterior motions of leg 2 into a mechanism for generating suction involves these highly modified cuticular structures. The endocuticular structure of the lunule of Caligus was unique and is key to our postulated actuating mechanism for the generation and release of suction. The morphological consistency of suckers and lunules across Caligus taxa implies a highly conserved attachment behavior that is effective on mucus-rich surfaces of a wide variety of fishes. In contrast, flexibility for attachment was also observed on the undescribed species of Caligus parasitic on the small ice goby.
  5. Carnivory and detritivory in oceanic calanoid copepods: functional morphological approaches, Susumu Ohtsuka, Sota Komeda & Tomonari Kaji, Tomonari Kaji, e-International Conference on Copepoda, 2022/07/25, With Invitation, English, World Association of Copepodologists, Online, Highly speciose planktonic calanoid copepods in marine ecosystems play pivotal roles in food webs. Based on their feeding habits, they are typically classified as particle feeders, carnivores, and detritivores. The latter two are the predominant groups in oligotrophic oceanic waters. In carnivores, highly specialized structures are found in the antennules and mouthparts. The main function of the maxillae and maxillipeds is grasping prey. Either or rarely both of these appendages are elongated for capture of prey in comparison with those of particle feeders. In some taxa, such as Euchaetidae, the maxillules are also involved in grasping prey. An extraordinary example is shown by four genera of the oceanic family Heterorhabdidae (Heterorhabdus, Paraheterorhabdus, Hemirhabdus, and Neorhabdus), which utilize “venom (or anesthetic)” like viper. In this study, we briefly explain how this venomous system works. “Venom” is produced in the labral glands and injected into prey via the fang-like ventralmost teeth of the mandible in harmony with muscle activity. A molecular phylogenetic analysis of this family revealed that evolution from a primitive particle-feeding genus to these advanced carnivorous genera may correspond to speciation of related families. Detritivorous calanoids are also dominant in the ocean, particularly in deep seas, some of which are sometimes called Bradfordian families. They have highly unique chemosensory and/or optical sensors to detect specific detrital matter. Chemosensory organs were located on the maxillary endopods and are much more complex than previously known. In addition to hundreds of sensory cilia reported by previous studies, cells similar to solitary chemosensory cells (SCCs) and free nerve endings were newly discovered in the chemosensory setae of Scolecitrichidae. These possible sensory cells have not been observed in any arthropod aesthetascs and are similar to vertebrate ones. In vertebrates, cilia and SCCs are known as highly-sensitive and persistent chemosensors, respectively. The combination of various sensory cells may enable multifunctional chemosensory organs. Contrary to Scolecitrichidae mentioned above, Phaennidae had developed cilia to compensate for the absence of SCC-like cells. In addition to these chemosensors, Bradfordian families sometimes had optical sensors with semi-parabolic reflectors or cuticular lenses. Comparative morphology found that chemosensory setae were developed in genera without optical sensors. These genera may have fed on odorous foods because they had various bacteria producing acyl-homoserine lactone in their gut. In contrast, genera with optical sensors had a higher frequency of bioluminescent taxa in their enteric bacterial flora. Bradfordian families may use chemical and/or optical bacterial signals from detrital foods, and seem to have sensory organs adapted to various feeding niches in oligotrophic environments.
  6. Global spread of aquatic parasites via aquaculture, aquarium and game fishing, Susumu Ohtsuka, International Forum on Post COVID Fisheries and Aquaculture Update in Japan, Indonesia and Malaysia, 2021/11/16, With Invitation, Japanese, University Sultan Zainal Abidin, Malaysia, online
  7. Taxonomic review of the copepod family Chondracanthidae Milne Edwards, 1840 (Copepoda, Poecilostomatoida) parasitizing the marine fishes from Indian waters, Ameri Kottarathil Helna1, Panakkool Thamban Aneesh, Appukuttannair Bijukumar, Balu Alagar Venmathi Maran, Susumu Ohtsuka, Ameri Kottarathil Helna1, Panakkool Thamban Aneesh, Appukuttannair Bijukumar, Balu Alagar Venmathi Maran, virtual International Conference on Marine Sciences & Aquaculture, 2022/03/10, Without Invitation, English, University of Malaysia Sabah, Malaysia (online)
  8. Tropical fish parasitic crustaceans: parasitic adaptations and emerging paradigms in research, Panakkool Thamban Aneesh, Ameri Kottarathil Helna, Appukuttannair Bijukumar, Balu Alagar Venmathi Maran, Susumu Ohtsuka, Panakkool Thamban Aneesh, Ameri Kottarathil Helna, Appukuttannair Bijukumar, Balu Alagar Venmathi Maran, virtual International Conference on Marine Sciences & Aquaculture, 2022/03/10, Without Invitation, English, University of Malaysia Sabah, Malaysia (online)
  9. Parasitism of the non-indigenous sea louse Caligus sclerotinosus among wild and farmed Red Sea bream Pagers major in the Seto Inland Sea, Japan, Yusuke Nishida, Susumu Ohtsuka, Ione Madinabeitia, Yusuke Kondo, Kenta Adachi, Hirofumi Yamashita, Sadaharu Iwasaki, Sho Shirakashi, Kazuo Ogawa, virtual International Conference on Marine Sciences and Aquaculture, 2022/03/10, Without Invitation, English, University of Malaysia Sabah, Malaysia (online)
  10. Seasonal occurrence of ctenophores and their parasites in the Seto Inland Sea, Japan E, Yusuke Kondom Dong Hang Li, Susumu Ohtsuka, virtual International Conference on Marine Sciences & Aquaculture, 2022/03/10, Without Invitation, English, University of Malaysia Sabah, Malaysia (online)
  11. Global spread of aquatic parasites via aquaculture, aquarium and game Fishing, Susumu Ohtsuka, virtual International Conference on Marine Sciences & Aquaculture, 2022/03/10, With Invitation, English, University of Malaysia Sabah, Malaysia(online)
  12. Hosts and seasonal occurrence of the planktonic sea-louse Caligus undulates in Japanese waters, Masaki Nawata, Susumu Ohtsuka, Yusuke Kondo, Yusuke Nishida, virtual International Conference on Marine Sciences & Aquaculture, 2022/03/09, Without Invitation, English, University of Malaysia Sabah, Malaysia (online)
  13. What could have happened to the evolution of the highly modified fish parasite Pennellidae: implication of evolutionary trends based on molecular analysis, Nanami Yumura, Kenta Adachi, Masato Nitta, Yusuke Kondo, Sota Komeda, Kaori Wakabayashi, Jun Fukuchi, Geoffrey A. Boxshall, Susumu Ohtsuka, Geoffrey A. Boxshall, virtual International Conference on Marine Sciences and Aquaculture, Without Invitation, English, University of Malaysia Sabah, Malaysia (online)
  14. Impact of jellyfish fisheries on their symbionts, Ohtsuka, Susumu, International Workshop on Emergent Issues of Marine Ecosystems in the Southeast Asia: For Sustainable Use of Marine Ecosystem Services, 2019/09/06, With Invitation, English, Atomsphere and Ocean Research Institute, University of Tokyo, Kashiwa City, Chiba
  15. Impact of jellyfish fisheries on their symbionts, Susumu Ohtsuka, Lecture for students of Universiti Sultan Sainan Abidin, Malaysia, 2018/11/01, With Invitation, English, Universiti Sultan Sainan Abidin, Terengganu, Malaysia
  16. Planktonic phases of symbiotic copepods, with a special reference to Caligidae, Susumu Ohtsuka, International Conference on Agriculture, Animal Sciences, and Food Technology, 2018/10/30, With Invitation, English, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
  17. Symbionts of jellyfish occurred in Thailand, Ohtsuka S, Y. Kondo, International workshop on classification and culture of jellyfish in Thailand, 2018/09/02, With Invitation, English, Burapha University and Department of Marine and Coastal Resources, Thailand, Bangsean, Trat
  18. Population structure of the "hitch-hike" ophiuroid, Ophiocnemis marmorata, associated with jellyfish, Hiruta, SF, Y. Kondo, J Nishikawa, Fed Yusoff, EB Metillo, H Pagliawan, K Srinui, S Ohtsuka, T. Fujita, 16th International Echinoderm Conference, 2018/05/28, Without Invitation, English, Nagoya University, Nagoya City
  19. Morphometric study on feeding appendages of pelagic calanoid copepods: relationship with feeding mode, habitat depths and stable isotopes, S. Sota,H. Tamura,Y. Abe, M.N. Aita,F. Hyodo,S. Ohtsuka,R.R. Hopcroft,A. Yamaguchi, A. Yamaguchi, 33th International symposium on the Okhotsk Sea and Polar Oceans, 2018/02/21, Without Invitation, Japanese
  20. Symbiotic biology and fisheries of jellyfish in southeastern Asia, Susumu Otsuka, 2nd International symposium on marine and fisheries research, 2017/07/24, With Invitation, English, Universities Gadjah Mada, Youyakarta
  21. Trophic interactions between bacteria and Bradfordian families, Katsushi Hirano, Susumu Otsuka, Kentaro Takada, Hideo Fukushima, Kentaro Takada, Hideo Fukushima, 13th International Conference on Copepoda, 2017/07/20, Without Invitation, English, World Association of Copepodologists, California, USA
  22. Morphometric study on the feeding appendages of planktonic calanoid copepods: relationships with feeding modes, habitat depth ,and stable isotopes, Sota Komeda, Hiroaki Tamura, Yoshiyuki Abe, Maki Noguchi Aita, Fujio Hyodo, Susumu Otsuka, Russel R. Hopcroft, Atsugi Yamaguchi, Atsugi Yamaguchi, 13th International Conference on Copepoda, 2017/07/20, Without Invitation, English, World Association of Copepodologists, California, USA
  23. Ecological studies on Panaietis yamaguchi that infect the buccal cavity of horned turbo, Turbo cornets, Hayato Uchiumi, Yusuke Kondo, Susumu Otsuka, 2017/07/19, Without Invitation, English, World Association of Copepodologists, California, USA
  24. Functional morphology of the cephalothoracic sucker of Callous, Taiki Fuji, Susumu Otsuka, Yusuke Kondo, Tomonori Kaji, Satoshi Yasumi, Tomonori Kaji, Satoshi Yasumi, 13th International Conference on Copepoda, 2017/07/19, Without Invitation, English, World Association of Copepodologists, California, USA
  25. Planktonic phases of symbiotic copepods, Susumu Otsuka, 13th International Confernce on Copepoda, 2017/07/18, With Invitation, English, World Association of Copepodologists, California, USA
  26. Behavioral observations of an undescribed hyperbenthic misophrioid copepod, with supplementary data on DNA sequences, Susumu Otsuka, Hayato Tanaka, Yusuke Kondo, Katsushi Hirano, Dame Jaume, Geoffrey A. Boxshall, Dame Jaume, Geoffrey A. Boxshall, 13th International Conference on Copepoda, 2017/07/18, Without Invitation, English, World Association of Copepodologists, California, USA
  27. Taxonomy and fisheries of commercially harvested jellyfish Crambionella (Scyphozoa) from central Java, Indonesia, Nishikawa J, Ohtsuka S, Mulyadi, Mujiono N, Lindsay DJ, Minamoto H, Nishida S, Asian CORE-COMSEA seminar on coastal ecosystems in southeast Asia, 2016/02/24, Without Invitation, English, University of Tokyo, Kashiwa, Japan
  28. Evolutionary shift from particle-feeding to carnivory in ccalanoid copepods: morphological and molecular evidences, Takeshi Hirabayashi, Makoto Urata, Ko Tomikawa, Susumu Ohtsuka, 12th International Conference on Copepoda, 2014/07/14, Without Invitation, English, World Association of Copepodologists, Seoul, Korea, In calanoid copepods exclusive carnivory is found in some lineages. In oceanic waters a wide variety of families or genera are supposed to be carnivores, whereas in coastal waters restricted members such as Euchaetidae, Pontellidae and Tortanidae are truly carnivorous. In the oceanic family Heterorhabdidae both particle-feeding and carnivorous genera are involved with some intermediate taxa, and the evolutionary shift from particle-feeding to carnivory has already been supported by the morphology-based phylogenetic analyses. The evolution in feeding of this family could have occurred without any addition of novel structure. Our new molecular analysis using nuclear ribosomal DNAs (18S, 28S) strongly enhances the results: the carnivorous Heterorhabdus-Paraheterorhabdus and Neorhabudus-Hemirhabuds clades are a final divergence, while the particle-feeding genus Disseta is basal with offshooting of the intermediate genera between these extremes. In calanoids two basic modes of carnivory are distinguished: chopsticks and scooping. The carnivorous genera of Heterorhabdidae, Candaciidae, Chiridiella and Corunucalanus are supposed to exclusively adopt chopsticks mode, whereas others essentially employ both feeding modes, depending on prey size. The former is characterized by only a few of highly chitinized elements on the maxillae only or maxillae/maxillipeds, while the latter is defined by the formation of feeding basket with the feeding appendages. The morphological and molecular phylogenetic analyses on the Heterorhabdidae propose that chopsticks mode could have divided directly from particle-feeding to carnivory not via scooping mode. We exactly traced the homology of maxillary and maxillipedal segments/elements specific to carnivory, and recognized 11 morphological types in carnivorous calanoids, suggesting that carnivory could have independently evolved many times through the evolution of calanoids.
  29. Complete life cycle of a pennellid Peniculus minuticaudae Shiino (Copepoda: Siphonostomatoida) infecting cultured threadsail filefish, Ismail Norshida, Susumu Ohtsuka, Balu Alagar Venmathi Maran, Satoshi Tasumi, Kassim Zaleha, Hirofumi Yamashita, Balu Alagar Venmathi Maran, Satoshi Tasumi, Kassim Zaleha, Hirofumi Yamashita, 12th International Conference on Copepoda, 2014/07/14, Without Invitation, English, World Association of Copepodologists, Seoul, Korea, Peniculus minuticaudae Shiino is a parasitic copepod infecting the fins of fishes mainly belonging to the family Monachantidae. Recently it seems to have been spreading in fish farms in western Japan and southern Korea. Our study showed the infection occurs all year round with the highest intensity recorded during summer. Based on our finding of all post-embryonic stages together with the post-metamorphic adult females on the fins of threadsail filefish Stephanolepis cirrhifer Temminck and Schlegel cultured in a fish farm at Ehime Prefecture, Japan, we newly proposed the complete life cycle the P minuticaudae. The hatching stage was observed as an infective copepodid. It metamorphosed into chalimi I to IV after infection on fins. Sex can be differentiated from chalimus I. Adult males were observed frequently in precopulation amplexus with various stages of chalimi, however, copulation occurs only between adults. Fertilized pre-metamorphic adult females carrying paired spermatophores may detach from the host, and settle again on the same host and site to undergo massive differential growth to become post-metamorphic. A comparison in of the life cycle of P. minuticaudae has been made with those of three known pennellids; Lernaeocera branchialis Linnaeus, Cardiodectes medusaeus Wilson and Lernaeenicus sprattae Sowerby. The life cycle of pennellids can be divided into four categories based on the number of hosts and the presence or absence of nauplii. Combinations are as follows: (1) L. branchialis (two hosts, nauplii present); (2) C. medusaeus (two hosts, no nauplii); (3) L. sprattae (single host, nauplii present); (4) P. minuticaudae (single host, no nauplii). In L. sprattae, adult females change infection sites from fins and body surface to eyes of the host for oviposition, whereas in P. minuticaudae all stages including ovigerous females infect fins of the host. In the family blood-suckers may have two hosts, while histophagous taxa may not change host and/or attachment site.
  30. Systematics, morphology and feeding of calanoid copepods, Susumu Ohtsuka, 12th International Conference on Copepoda, Preconference Workshop, 2014/07/08, Without Invitation, English, World Association of Copepodologists, Yosu, Korea, The systematics, morphology and feeding of calanoid copepods are explained in detail, using powerpoint.
  31. Associations of fish juveniles and benthic invertebrates with large-sized jellyfish in Asian waters: key issues in pelagic realms, Susumu Ohtsuka, Yusuke Kondo, Shoma Okada, Jun Nishikawa, Khwanruan Srinui, Ephrime Metillo, Fatimah Md. Yusoff, Nanako O. Ogawa, Naohiko Ohkouchi, Shuhei Nishida, Jun Nishikawa, Khwanruan Srinui, Ephrime Metillo, Fatimah Md. Yusoff, Nanako O. Ogawa, Naohiko Ohkouchi, Shuhei Nishida, 9th International Scientific Symposium (IOC/WESTPAC), 2014/04/22, Without Invitation, English, IOC/WESTPAC, Nha Trang, Vietnam, Large-sized jellyfish harbor a wide variety of fish and invertebrates as hosts. However their actual interactions are rarely addressed, because of difficulties in assessment of trophic relationships between them and of little information on roles of the host throughout the life cycle of symbionts. We have been intensively investigating these interactions in Asian waters with modern techniques such as stable isotope analyses. In East Asian waters, scyphozoans such as Aurelia aurita s.l., Chrysaora pacifica, Cyanea nozakii and Sanderia malayensis are frequently associated with butterfish juveniles during warm seasons. Essentially the fish utilize jellyfish for commensalism or antipredation, however, the ontogenetic changes in symbiosis are suggested based on the stable isotopic analysis. The fish tends to feed on the host tissues, as it grows. The shrimp Latreutes mucronatus is highly specific to the Netrostoma setouchiana. The highly venomous box jellyfish Morbakak virulenta also shows complex interactions with fish. In southeastern Asian waters two commercially harvested rhizostomes, Rhopilema hispidum and Lobonemoides robustus, play an important role as host for fish juveniles (shrimp scad Alepes djedaba) and invertebrates (cross crab Charybdis feriata and hippolytid shrimp La. anoplonyx). These interactions seem to change with the growth of these symbionts as observed in butterfish in East Asia. In case of sympatric occurrence of these two hosts, shrimp scad juveniles exhibit habitat segregation: larger individuals prefer R. hispidum to Lo. robutus. An association between the ophiuroid Ophiocnemis marmorata and these rhizostomes is broadly observed in tropical Asian waters, corresponding to commensalism. Our results strongly imply that larvae of these benthic animals most likely settle directly on the jellyfish host and then temporarily stay there until the death o f the host. On the other hand fisheries of these edible jellyfish seem to have a great negative impact on the recruitment of these symbionts.
  32. Undescribed species of the commercially harvested jellyfish Crambionella (Scyphozoa) from central Java, Indonesia with remarks on the fisheries, Jun Nishikawa, Susumu Ohtsuka, Mulyadi, Nova Mujiono, Dhugal J. Lindsay, Hiroomi Miyamoto, Shuhei Nishida, Jun Nishikawa, Mulyadi, Nova Mujiono, Dhugal J. Lindsay, Hiroomi Miyamoto, Shuhei Nishida, 9th International Scientific Symposium (IOC/WESTPAC), 2014/04/22, Without Invitation, English, IOC/WESTPAC, An undescribed species of Crambionella is discovered from central Java, Indonesia. The number of lappets per octant (14), presence of foliaceous appendages on oral-arms, absence of tubercles on the velar lappets, and the body colour distinguish this species from three previously-described congeners. In addition, the analysis of partial sequences of the cytochorome c oxides subunit I gene indicated substantial genetic differences from both C. orsini and C. stuhlmani, supporting the validity of this new species. A combination of morphological and genetic approaches determined that the remarkable differences in exumbrellar colors observed in specimens is simply intra-specific variation. Surprisingly, this species has been commercially harvested for more than 20 years and is well-known to the local people in the region, yet it had remained unknown to science until this point. The commercial fisheries targeting this formerly unknown species are also presented in detail.
  33. Functional morphology of calanoids copepods; Evolution of planktonic copepods, Susumu Otsuka, 2003/07, With Invitation, Japanese
  34. Morphology and Systematics of planktonic copepods, Susumu Otsuka, Eighth International Conference on Copepoda (Preconference Workshop), 2002/07, With Invitation, Japanese
  35. Seuxal dimorphism in calanoid copepods-morphology and function, Susumu Otsuka, The World Association of Copepodologists, 1999, With Invitation, Japanese

Awards

  1. 2020/08/21, Early Career Outstanding Posters: Honorable Mention, Deep-Sea Biology Society/DSBS, An undescribed genus and species of the phylum Loricifera from Japanese Waters, Northwest Pacific
  2. 1999/09, Zoological Science Award, 日本動物学会, "学術論文「Platycopia compacta n.sp.,the second species of Platycopioida (Crustacea: Copepoda) in the Indo-Pacific region, wi

Social Activities

History as Committee Members

  1. Executive Council, 2021/04/01, 2022/03/31, World Association of Copepodologists
  2. Vice President, 2021/04, 2024/03, The Plankton Society of Japan
  3. Vice President, 2021/04, 2024/03, The Plankton Society of Japan
  4. Vice President, 2021/04, 2024/03, The Plankton Society of Japan
  5. Associate editor of Marine Biodiversity, 2020/04, 2021/03, Springer
  6. Executive council members, 2018/04, 2019/03, Plankton Society of Japan
  7. Council members of World Association of Copepodologists, 2017/07, 2022/06, World Association of Copepodologists
  8. Council members of World Association of Copepodologists, 2017/07, 2022/06, World Association of Copepodologists
  9. Council members of World Association of Copepodologists, 2017/07, 2022/06, World Association of Copepodologists

Organizing Academic Conferences, etc.

  1. Workshop on jellyfish, member of UNESCO program, 2019/09, 2019/09
  2. Workshop on jellyfish, member of UNESCO program, 0908/, 0911/

Other Social Contributions

  1. 15th International Conference on Copepoda, Executuve and Local Commitee Members (chairman), World Association of Copepodologists, 2022/04/01, 2025/03/31, Hiroshima City, Takehara City, Organizing Member, Meeting or assembly, Scientific organization

History as Peer Reviews of Academic Papers

  1. 2021, ZooKeys, Others
  2. 2021, International Journal for Parasitology: Parasites and Wildlife, Others
  3. 2021, Plankton and Benthos Research, Others
  4. 2021, Parasitology International, Others
  5. 2021, Philippine Journal of Systematic Biology, Others
  6. 2021, Life, Others
  7. 2021, Journal of King Saud University-Science, Others
  8. 2021, Journal of Natural History, Others
  9. 2021, Indian Journal of Geo-Marine Sciences, Others
  10. 2021, Ichthyological Research, Others
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