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 seawater, 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. 
Fic. 79, Tue Sea Horse (Life size) 
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 
