72G SCIENTIFIC RECOKD FOR 1683. 



scribed a very peculiar and remarkable fish found in Japan as Salmo 

 (Plecoglossus) altivelis. In I860 Giinther recorded specimens from For- 

 mosa as well as Japan. Nothing, however, seems to have been known 

 to Europeans respecting the habits of the species till 1883. It now 

 appears that the form is of unusual interest. Mr. K. Nabeshima, in a 

 communication to Mr. Narinori Okoshi, of the Japanese consulate at 

 London, the author of "A Sketch of the Fisheries of Japan", (p. 35), 

 gives some interesting details. The fish has the elegant appearance of 

 a young salmon or smolt, but the teeth of the sides of the upper jaw 

 (supramaxillaries) are of a broad lamelliform shape, and the rami or 

 branches of the lower jaw are not joined at the symphysis, but each juts 

 out into a small knob. According to Mr. Nabeshima, it varies in size 

 from about 6 to 12 inches, and inhabits fresh and rapid streams, except 

 in the breeding season. On the approach of the period of reproduction, 

 which is autumn, it descends the stream to the estuaries for the purpose 

 of spawning. After this labor is performed the old die out and the 

 species is represented only by the young, which ascend the streams, 

 grow to full size, and in their turn descend the next season to repeat 

 the cycle of life. The species igfconsequently known as the u one -year fish." 

 The special interest connected with the species results from the fewness 

 of those which have analogous habits. Certain gobies of the genera 

 Aphya and Crystallogobius have been shown by Professor Collett to be 

 annual fishes, while the common eel, the Retropinna* of New Zealand, 

 and some species of Galaxias, are the only certain known catadromous 

 fishes or visitors to the sea for reproduction. Although doubtless there 

 are others, the ahyu is especially worthy of record as the only fish 

 known to combine the habits of the two classes indicated. Like the 

 smelt, the ahyu has a "smell remarkably resembling that of the cucum- 

 ber." ^It is very sensitive, and the slightest handling is immediately 

 fatal to it; further, its flesh rapidly deteriorates in flavor, and it there- 

 fore cannot be conveyed to distant markets. When fresh, however, it 

 is " considered the most delicately flavored of all river fish " in Japan. 

 The combination of proueuess to Speedy decay and delicacy of flesh 

 naturally causes it to be " somewhat expensive." It rises to the fly, and 

 this habit is taken advantage of as a preliminary to a peculiar mode of 

 capture which has been described by William Pierre Jouy (Proc. U. S. 

 Nat. Mm., vol. vi, p. 275, December 13, 1883). "After whipping the stream 

 with flies, as for trout, and securing a fish, a fine gut line is passed 

 through tile nostrils and fastened to a line held in the hand ; trailing 

 behind the fish thus fastened, which is simply a decoy, are several bright 

 hooks, which flash in the sunlight and attract other fish. The decoy is 

 now gently led up stream, and the fish, in darting after it, get snagged 

 on the hooks." Horse-hoof parings, used as lures, are also said to be 



* Possibly the Retropinna and Galaxias are also "annual" fishes. 



