The life history and habits of the sculpin, \u22Yama-no-kami\u22, Trachidermus fisciatus Heckel

In this paper the writer deals with the life history and habits of the sculpin, Trachidermus fasciatus Heckel, vernacular name: \u22Yama-no-kami”(MountainWitch).Most of the data were obtained in the Rivers Chikugo and Yabe as well as in Ariake Sound, Kyushu. The distribution of this fish in Japan is very restricted, namely to Chikugo River and several adjoining streams which empty into the innermost part of Ariake Sound. It occurs in West Corea and North China. (1) It inhabits usually the upper and middle part of the stream and is often found under rocks or stones which provide shelter. It prefers crustaceans throughout the life. (2) In the winter, when the spawning season approaches, the nuptial coloration appears in the adult fish, both in male and female, the gill-membranes and the base of the anal fin becoming brightly scarlet. The spawning migration takes place from November to December, when it runs down the stream at night. The spawning season is from January to March, and the spawning takes place on the sandy tidal flat of the innermost part of Ariake Sound. The masses of the eggs are laid in the empty shell of a large bivalve, Atrina japonica(Reeve), and are guarded by a male parent during the incubation period. The majority of the spawning fish are those of two years, a few spawning at the end of one year. Most parent fish seem to die after spawning. (3) The egg is orange-red in color, demersal and adherent, 2.0～2.2mm in diameter. The number of eggs in a mass ranged from 5,110 to 6,120. The number of the eggs carried a by an adult female varied from about 5,000 to 11,000. The larva carries pelagic life in the estuary for several months and later ascends the stream in a shoal. The young fish sets in a solitary bottom life. In one month it attains about 20mm in total length; in thre months 40～60mm; in full one year100～120mm; in full two years about 160mm long. It attains a length of about 170mm, and the male is a little larger than the female. (4) It is said by the fishermen of this destrict that the descending migration of this fish denotes the end of the freshwater fishery in the year. Its flesh is firm and sweet, though it is not so highly valued as food fish in Japan as in China.ヤマノカミ Trachidermus fasciaius Heckel はカジカ科 Cottidae の淡水魚で，日本においでは福岡・佐賀両県の有明海湾興部にそそぐ河川にのみ棲息し，その局限された分布が動物地理学上興味をもたれている． しかしわが国における本種の生態及び生活史については，木下盛枝氏(1931，1941)の断片的報告があるにすぎない． また本種は，すでに知られている通り， 中国の有名な“松江の鱸魚”で一名“四鰓鱸”とも言われ，古来その味を賞美するとともに，詩などにも表われているが， その生態・生活史については，中国においでもいまだ明らかにされているところは少ない．日本産の他のカジカ科の魚についても，淡水産のカジカ Cottus pollux 及びカマキリ Cottus kazikaについての二三の報告があるにすぎない．筆者は最近5，6年間，筑後川，矢部川及び有明海の魚類の生態的研究を行っているが，その間に蓄積された資料と，木下盛枝氏より提供された標本とによつて，本種の生態・生活史の概要を報告する．カジカ科の魚で，形態及び生態がよく似たものにカマキリ Cottus kazika (各地の方言：アユカケ， アイキリ， アイカギ， アラレガコ， タキタロウ)があつて，本種と混同されることが?々あるが，カマキリは日本における分布が広く，南日本の河川に棲息するが，日本海側はかなり北方まで分布し，ヤマノカミよりも大形になる．この研究にあたり，終始御指導を賜わり本稿の御校閲をいただいた内田恵太郎教授に厚くお礼申しあげるとともに，貴重な標本をいただき且つ採集の援助を賜わつた福岡県柳川町在住の木下盛枝氏に深謝する．叉標本の整理・測定をしていただいた教室員：柴田チヅ子嬢，高木多恵子壊，描画の助力をしていただいた坂本秀子嬢，採集に協力下さつた漁業者：高椋校伊左男，垣三郎，宮崎雅広，-江崎藤蔵の諸氏に感謝の意を表する．なおこの報告の測定値はすべて固定標本によつた．卵及び稚仔は10%ホルマリン固定後， 70%アルコール中に保存したもの，成魚は10%ホルマリンに固定保存したものを用いた