TROPICAL AQUARIUM FISHES 117 



induce them to eat daphnia, it has seldom been accomplished. The 

 author was fortunate enough to induce Sea Horses to modify their ideas 

 on diet, the process taking considerable patience. Daphnia can only live 

 about 5 minutes in seavvater, so at first they all die while the Sea Horses 

 are apparently thinking the matter over. By repeated trials the smaller 

 fishes finally started to eat and the larger ones took the hint from the 

 smaller. Shrimp will eat the dead daphnia, but if much is left over it 

 should be quickly siphoned out or otherwise removed. Sea Horses can, 

 no doubt, be brought to living in saltwater of a hydrometer strength of 

 1,017, which would probably increase the length of life of daphnia in the 

 marine aquarium to 10 minutes or more. As the Sea Horses usually eat 

 by reaching out for food while attached by their tails to a piece of sea- 

 weed, it is necessary to gently circulate the daphnia through the aquarium 

 by the aeration system or other means. 



Fig. 79. The Sea Horse (Life sice) 

 Hippocampus hudsonius 



These strange fishes are of worldwide distribution. On the Atlantic 

 Coast they are more plentiful in September than at any other time, when 

 they are often brought up clinging to fishermen's nets. Only one species 

 occurs on the Atlantic Coast. This is the one shown in Fig. 79. 



Feeding in Marine Aquaria. Practically all marine animals are 

 carnivorous. Chopped oysters, clams, fish, worms, crab meat, scraped 

 lean beef and shrimp form the principal articles of diet. Uncooked 

 shrimp, shelled and put through the finest meat chopper is excellent and 



