320 U. S. BUREAU OF FISHERIES 



useful for moving plants and other objects without putting the hands 

 into the water. 



Sea-water aquaria are managed according to the methods applic- 

 able to aquaria for fresh-water animals. There must be a similar 

 balance between the marine animals and plants that they contain. 

 Seaweeds here take the place of pondweeds, green sea lettuce (Ulva) 

 being the most desirable, though others are used principally for 

 their colors. 



Pure sea water is required, and many of the small inhabitants of 

 the rock pools are available. Killifishes, shrimps, crabs, hermits, 

 anemones, young starfishes, tunicates, small mollusks, northern coral 

 (Astrangia), and marine worms have all been kept successfully in 

 the laboratory collection of the New York Aquarium. Planting is 

 done as in fresh- water aquaria, the seaweeds being anchored in the 

 gravel and sand of the bottom. Sea lettuce is floated at the surface 

 with the support of corks. 



Marine aquaria need more light than those containing fresh water. 

 Finely cut fresh clam and mussel is the principal food, but bits of 

 dried shrimp and fish (unsalted), with a little fresh fish, may be 

 used. 



Care is necessary in feeding. Aeration witli the dipper and the 

 siphoning out of refuse are sometimes required. 



Turtles and alligators, being cold-blooded reptiles, must have 

 warm quarters. They should be kept in aquaria or other vessels into 

 which sunlight can enter and the vessel placed where it will not 

 become cold. If kept near a window in winter to receive the sun- 

 shine, which is life to them, they should also be near a heater. The 

 temperature of the ordinary living room in winter is scarcely high 

 enough to keep baby alligators active, as they need a warmth of 80° 

 to 85°. 



Alligators require not only warm water but a place where they can 

 dry off at times. The water need not be more than a few inches 

 deep, and the platform or small log on which they rest should be 

 placed in such a way that they can climb upon it easily. Alligators 

 in captivity are most comfortable and active when they have access 

 to water that is nearly tepid, and it is their habit to float much 

 on the surface. Turtles require not only warm water but also the 

 heat of the sun. The temporary warming of torpid alligators or 

 turtles in boxes set near a heater is useless. If they can not be kept 

 where both air and water are permanently warm, they should be 

 dispensed with. 



The numerous chilled and weak alligators sent to the aquarium 

 are placed in a tank of water with a steam pipe in it. After a 

 thorough warming up in water of 85° temperature, they begin to 

 feed and will grow rapidly. Forcing cold alligators to eat by 

 cramming food into their mouths is admissible only temporarily. 



Alligators and snapping turtles are flesh eaters and may be 

 provided with small minnows, frogs, tadpoles, worms, grubs, cray- 

 fish, shrimps, and small crabs, either dead or alive. When these 

 can not be had they will eat fresh chopped meat, fish, clams, and 

 oysters. Many kinds of turtles will eat all of the above-named 

 foods as well as snails and insects. Others like very tender, green 

 vegetables, such as tomatoes, lettuce, celery, and various water plants. 



