The distributions of eight crab species belonging to five genera in the families, Hymenosomatidae, Pilumnidae and Varybudae, were studied on the basis of 1390 specimens collected in 2003 and 2004 from brackish waters in the rivers and estuaries in Kochi Prefecture, in southern Japan. Halicarcimus messor (Hymenosomatidae), Pilummopeus marginalus(Pilunnidae) and Phychoganthus capillidigitatus (Varunidae) were recorded for the first time in the Kochi Prefecture. A total of 192 specimens confirmed the widespread occurrence of Neorhynchoplax okinawaensis (Hymenosomatidae) in the study area. Prior to this study only five individuals of N. okinawaensis had been recorded as Halicarcinus orientalis from Urado Estuary, in Kochi City. Pilumnopeus makianus and Phychognathus ishii were common species in this estuary, but the precies distributions of these species were unknown prior to this study, Specimens of two varunid species, Acmaeopleura toriumii and A. parvula, were also collected. The presence of these species suggested that the brackish water crab fauna in the present study area contained rare Japanese species, that were similar to those found on the western coast of the Kii Peninsula.
In this study, the occurrence of the following three small crabs species (Domecia glabra, Tetralia glaberrima and Tetralia nigrolineata) associated with Acropora sp. have been reported in Shimizu Port (32°45′N，132°57′E)
Kochi Prefecture. Domecia glabra and T. nigrolineata were reported for the first time in the Kochi Prefecture. In addition, the record for T. nigrolineata represented the most northely record for this species. The specimens of T. glaberrima collected from outside Tosa Bay represented the second record of this species from Kochi Prefecture. New Japanese names for Domeciidae and Tetraliidae have been proposed, and the Japanese names for T. glaberrima and T. nigrolineata were discussed.
The occurrence of pipefishes and seahorses (family Syngnathidae) was studied in Urado Estuary, Kochi Prefecture, from April to October 2004. A total of 28 specimens of five species in three genera were collected from intertidal sandy-mud flats in the southern region of Urado Estuary. The occurrence of two species, which are endangered in Kochi Prefecture, Syngnathus schlegeli and Hippichthys (Hippichtlys) spicifer, was confirmed. The former was discovered in Urado Estuary for the first time in over 20 years. Twelve specimens of Hippocampus kuda, a species known from the Ryukyu Islands southward in Japan, were collected from April to October. A single, male H.(H.) spicifer carried eggs in its blood pouch, whilst female of other species had fully developed ovaries. These facts strongly suggest that spawning and nurturing of syngnathid fishes occur in Urado Estuary.
In this study eighteen coastal fish species which were previously unknown or poorly knows in Kochi Prefecture, southern Japan have been collected from 13 localities. Previously most of these species have only ever been recorded in warmer subtropical waters of Japan. On the basis of this study six species have been added to ichthyofauna of Kochi Prefecture. Festucalex erythraeus, Scorpaenodes guamensis, Stegastes fasciolatus, Cheilinus trilobatus, Acanthurus maculiceps and Rhinecanthus verrucosus. The specimens of Plectorhinchus gibbosus, S. fasciolatus, C. trilobatus and A. maculiceps represent the most northerly record for each of these species.
The ectoparasites of wild mammals, obtained recently in Kochi Prefecture, are listed. These parasites include the scabies mites Sarcoptes scabiei, and the tick species Amblyomma testudinarium and Haemaphysalis formosensis on the wild boar Sus scrofa. Tick species H. flava and H. longicornis, and two unidentified species of insect were found on the raccoon dog Nyctereutes procyonoides. The bat fly spesies Brachytarsina kanoi, Phthiridium hindlei, Penicillidia jenynsii and Nycteribia parvula, and the mite species Spinturnix myoti and Icharonyssus were found on the bat species Rhinolophus ferrumequinum, Myotis macrodaclylus and Miniopterus fuliginosus.
2004年4月1日に高知県佐賀町沖の土佐湾の水深約120mにおいて，佐賀漁協の小型底曳き網漁船により，１個体のトビエイ亜目魚類（BSKU 87842，体盤長867㎜，体盤幅664㎜）が漁獲された．この標本は鰓孔が6対，吻が長くて寒天質に富む，眼が極めて小さい，噴水孔は大きくて眼からやや離れた後方に位置する，尾棘を持つことにより，ムツエラエイ科のムツエラエイ Hexatrygon bickkelli Heemstra and Smith と同定された．日本周辺において，本種はトカラ列島沖の沖縄舟状海盆，和歌山沖，愛知沖，相模湾で各１個体の標本が採集され，伊豆大島沖の水深38mおよび伊豆半島大瀬崎の水深15-20mで遊泳個体がダイバーにより観察および撮影されているにすぎず，土佐湾から初めて報告される．ムツエラエイ属には，H. bickelli, H. longrostra, H. yangi, H. taiwanensis, H. brevirostra の5種が記載されているが，おもに吻の長さと形状がその識別形質とされていた．その後，これらの形質は成長に伴い変化することが示唆され，H. bickelli のみが有効種と考えられている．しかし，日本では H. longirosta の学名が広く使われてきた．本報告で既知標本の体盤長と吻長の関係を調べたところ，吻は明瞭な優成長を示すことが判明した．この結果は，本属が１種のみを含むとする最近の見解を支持する．
Young specimens of Scatophagus argus, one of the near endangered fish of Koch Prefecture, were collected from Urado Estuary and the Takeshima River in 2004. In the Kochi Prefecture, the occurrence of this fish has been recorded only from the Shimanto, Kakise and Shinkawa Rivers and Kashiwa-jima. The specimens obtained in 2004, and a single sub-adult specimen collected from the Shimanto in 1974, are described and illustrated in detail.