346 



ZOOLOGICAL SOCIETY BULLETIN. 



BLIND FISHES. 



IN USING the term "blind" fishes it should 

 be explained, in so far as the fresh watei 

 kinds are concerned, that the fishes are not 

 without eyes, but have practically lost the use 

 of them through long-continued subterranean 

 life. The eyes are very small and are so thickly 

 covered with skin as to be useless. Blindness 

 of this kind is found not only among cave 

 fishes, but cave salamanders, crayfishes, and 

 other crustaceans as well. 



Blind animals are usually obtained by col- 

 lecting from streams which flow through cav- 

 erns such as that of the Mammoth Cave, and 

 most of the species known have been described 

 from caves in Kentucky, Tennesse, Illinois, 

 Indiana, Missouri, Arkansas and Kansas. 



Blind fishes and crustaceans are often 

 brought to the surface through the agency of 

 artesian wells. One genus of salamander, 

 (Typhlomolge) is known only from an arte- 

 sian well in Te.xas, where blind crustaceans 

 also frequently appear. 



Blind cave fishes are usually small, seldom 

 reaching a greater length than five inches. 

 Some of the species are known only from 

 caves or underground streams, while others 

 are found in the same regions in surface waters 

 with eyes better developed. The origin of 

 some of these fishes is unknown, their ances- 

 tors having entered caves a very long time ago. 



The principal genera are Chologastcr, Typli- 

 lichthys, Amblyopsis and Troglichthys, the eye 

 in the last named genus being the most de- 

 generate. It has probably lived in caves and 

 done without the use of its eyes longer than 

 any other vertebrate. It inhabits underground 

 waters in Missouri, Arkansas, and Kansas. 



Three dififerent genera and species are 

 known to live in the Mammoth Cave in Ken- 

 tucky, and specimens from there have at dif- 

 ferent times been brought to the New York 

 Aquarium. One of these {Typhlichthys sub- 

 terraneus), has been in the building two years. 

 It is a very small fish, less than three inches in 

 length. It is fed in summer on mosquito 

 larvae, when it can be obtained, and in winter 

 on Gammarus, a small crustacean, two species 

 of which are readily obtainable about New 

 York Harbor, both in salt and fresh-water. 

 Changes of light produce no effect on it, but it 

 IS extremely sensitive to disturbances of the 

 water. 



Another fish, nearly blind, lives in the dark 

 water of the Dismal Swamp in Virginia and 

 southward. Its eyes are well developed, but 

 small. Two other species of blind fishes are 

 found in caverns in Cuba, and a nearly blind 



species of catfish is found in caves in Penn- 

 sylvania. 



Some of the deep-sea fishes are totally blind, 

 with no e.xternal appearance of eyes whatever. 

 In such fisiies the organs of touch are highly 

 developed. Some of the deep-sea species also 

 possess phosphorescent organs. The strictly 

 cave animals are usually colorless, having the 

 appearance of albinos, but the blind fishes of 

 the deep-sea are dark or black. 



AQUARIUM NOTES. 



Aquarii.m Iinprozxiiicnts. — With new boil- 

 ers, ventilating plant, and thermostat attach- 

 ments to heaters, the Aquarium has been de- 

 cidedly more comfortable to visitors during the 

 past winter. The more equable temperature 

 has doubtless been helpful in keeping some of 

 the air-breathing animals in better conditions 

 of health than heretofore. 



Since the last Aquarium number of the 

 Bulletin appeared, the exhibits have been 

 slightly increased, by the introduction of three 

 very large table aquaria, to hold the collection 

 of small alligators, some of the fresh water 

 turtles, and the sea-horses. The last have 

 done much better in their tank of stored sea 

 water than in the wall tank supplied with water 

 from the harbor. The refrigerating machine 

 used in summer, the aerating plant and the 

 pump and tank rooms — with their apparatus — 

 have been thoroughly overhauled and painted. 



The building is being wired for additional 

 electric light, which is much needed on dark 

 days. Some of the balcony tanks have been 

 put out of commission for the introduction of 

 new piping. Otherwise the exhibits are as 

 large as the amount of tank space in the build- 

 ing will permit. 



The Aquarium Fish-Hatchery. — The fish- 

 hatchery has been kept in constant operation, 

 the eggs of several species of fishes having 

 been supplied, as heretofore, by the United 

 States Bureau of Fisheries from Government 

 hatcheries. The crop of young fishes has been 

 large, and has been turned over to the State 

 Fish Commission as usual. 



The Manatee. — The small manatee pre- 

 sented by Mr. A. W. Dimock last September 

 still feed's freely, and is doing well after six 

 months of captivity. The bruises it received 

 during transportation are healing slowly. 



Game Fish.— Mr. A. B. Davis of Wading 

 River, Long Island, presented to the Aquarium 

 the collection of pickerel exhibited by him at 



