Water-boatmen, or boat-flies, are so named from their resemblance to tiny boats with oars. As they have to swim on their backs, they are provided with large and very observing eyes. When they breathe they come to the surface, and by a quick diving motion, and the assistance of numerous stout hairs on the hind parts of their bodies, they entangle a mass of air, which, as they descend, spreads, giving their bodies a bright silvery color.
It is best to keep these aquatic insects by themselves, as they are all voracious feeders, and fierce in their habits. They are not so beautiful in form, color, and motions as fish, but possess a much greater interest as they pass through their many transformations. As most of them can fly, the aquarium should be provided with a close-fitting frame covered with mosquito netting.
CRIMSON-SPOTTED NEWT.
The crimson-spotted newt is one of the most inoffensive of all animals for the aquarium, and is valuable from the fact that he does not breathe water, but rises to the surface to breathe. Every few weeks he casts his skin, which he swallows, seeming to relish it, after which he comes forth more brilliant than ever.
TADPOLE.
An aquarium without tadpoles, from which to obtain a supply of small frogs, is not much of an aquarium; and as they are also surface breathers, you can use them freely.
The rock-fish is a very safe fish for the aquarium, as it does not breathe the water, but rises to the surface, and stores away a supply of air, with which it descends to the bottom, remaining for half an hour before it rises for a new supply.
All fresh-water fish (excepting the trout family) can be kept in a fresh-water aquarium. Select the very smallest specimens; have all of an equal size, to prevent their quarrelling; feed on shreds of raw beef, or earth-worms that have been freed of all earthy matter by placing them in damp moss or grass overnight. Look out for food not eaten.