76 



ZOOLOGICAL SOCIETY BULLETIN 



instead. In the meantime it is being cleared 

 somewhat by the use of alum, and a less 

 amount will be passed through the filters by 

 supplying the feed-pipes to the tanks with 

 small jets, which will secure an amount of 

 aeration hitherto secured by a stronger flow 

 of water. 



The ventilation of the Aquarium building, 

 while not a very serious matter during the 

 winter months, will require attention in sum- 

 mer, when larger crowds visit the building, 

 and can be greatly improved by the intro- 

 duction of electric fans. 



The collections should be made much more 

 instructive than has been possible by the 

 present system of labels. Transparent labels 

 are now being introduced, which will, when 

 completed, give to visitors considerable infor- 

 mation on each species exhibited and can be 

 read without strain to the eyes. 



In order that the Aquarium may have a 

 constant supply of local fresh and salt water 

 fishes, a field collector has been added to the 

 force, who will also be able to supply an im- 

 portant amount of the material used in feed- 

 ing the collections in general. 



FISH H.\TCHERY. 



A fish hatchery has been installed in one 

 of the floor pools of the Aquarium, which 

 has proved a most satisfactory addition to its 

 attractions. It has a capacity of about two 

 million fish eggs at one time, and hereafter 

 visitors will be able to see many species of 

 our native food fishes being hatched arti- 

 ficially in season. The accompanying pho- 

 tograph shows the hatchery in working or- 

 der. Its apparatus is placed on the broad 

 stone coping of the pool, and embraces that 

 customarily used in modern fish culture. 

 Three hundred thousand fish, including five 

 difTerent species, have been hatched out suc- 

 cessfully. Through the co-operation of the 

 United States Fish Commission and the New 

 York State Fish Commission, the hatchery is 

 operated without expense to the Aquarium, 

 the voung fish being planted in State waters. 



The heavy eggs of trout and salmon are 

 hatched in the troughs at the side of the pool, 

 while the semi-buoyant eggs of whitefish and 

 shad are placed in the McDonald jars 

 mounted at the north end. Boxes are provided 

 at the opposite end for young fish during the 

 period of absorption of the yolk-sac, and the 

 ]30ol itself will become a rearing-pond for 

 fish as soon as they are old enough to begin 

 feeding. 



The first fish eggs received (14,000 eggs of 

 the rainbow trout) were placed in the hatch- 

 ery early in January, and were all hatched 

 within a month, the loss during incubation 

 being less than 300. The young fish were 

 passed into the rearing boxes, and the hatch- 

 ing-trays filled with eggs of the brown trout. 

 The period of incubation of the rainbow trout 

 is 45 days, with a water temperature of 50 

 degrees, and the young fish in the rearing 

 boxes should absorb the yolk-sac in about 

 30 days at the same temperature. The brown 

 trout were hatched out by the 7th of March, 

 the loss amounting to practically nothing. 

 Fifty thousand lake-trout eggs were then 

 placed in the hatching-trays. Shad eggs are 

 being procured and the exhibition of fish 

 hatching is assured for about eight months 

 of the year. The hatching-jars were filled 

 with 275.000 eggs of the whitefish. all of 

 which have hatched out, a portion of the 

 young fish being still on exhibition. Since 

 the installation of the hatchery it has been 

 constantly surrounded by visitors, who have 

 been greatly interested in seeing the young 

 fishes in various stages of development, and 

 have asked the attendants many questions re- 

 specting the methods of modern fish propa- 

 gation. 



There is no reason why the Aquarium 

 hatchery should not be a local school for fish 

 culture. America leads the world in this mod- 

 ern science, and the Government plants more 

 than nine hundred millions of young fish in 

 our waters every year. This important work 

 is also supplemented by the various state fish 

 commissions throughout the country. 



A LARGE SNAPPING TURTLE. 



The Aquarium received a specimen of the alligator 

 snapping turtle {Macrochclys teiniiiincki) early in 

 December, which promised to be a very interesting 

 addition to its collections, but the animal arrived in 

 such an emaciated condition that it could not feed, 

 and it soon died. The alligator or southern snap- 

 ping turtle is very much larger than the northern 

 species, sometimes reaching the weight of 150 pounds. 



This specimen was 4V2 feet long, measured from the 

 snout to the end of the tail, and weighed io6j<3 

 pounds. It must have weighed very much more 

 when in good condition, and appeared to have the 

 marks of great age. The large inner claws of the 

 fore feet were worn nearly off. It was secured in 

 the city markets, and was said to have come from 

 Memphis, Tenn. 



The specimen has been mounted as a trophy for 

 the Aquarium. 



