Among the s and the water weeds of the shallows, lurk es, s, mud minnows, and young . All of these forage upon snails, crustaceans, and insect larvæ,… - Ann Haven Morgan

es posses much more beauty and interest than their reputation credits them with. Most of them are marked with concealing colors and patterns, browns, greens, and blacks, picturing upon them the broken shadows and water-soaked leaves of their natural background and hiding them in it. They are sensitive to the slightest vibration of the water, to shadows passing over them, and to small changes in the water around them. Their whole set up is one of exquisite efficiency for their mode of living. … The external features most essential to a leech are the strong muscular suckers at each end of its body and the sucking mouth which which may or may not be armed with jaws … Leeches are segmented worms like bristleworms and common earthworms and belong to the Phylum .

… Wherever animals live, in fresh water, salt water, or on land, their body fluids are similar; all are salty. In marine invertebrates, whether es or s, the body fluids are practically filtered sea water.

Different waters hold their own special communities; the dainty glen stream shelters companies of mayflies in its swift riffles; pond shallows and meadow brooks are the homes of lurking ; and wayside puddles are populous with mosquito wrigglers and . In all these places living things must contend with winter cold and summer drought, with storms and flood waters. In winter the pond populations drop to the bottom, frogs and turtles dig under mud and broken plants, whirligig beetles hide under banks to come out with every warm spell, and fresh water sponges are packed in tough covered capsules. In summer when its own pool dries up the water boatman flies to some other pond but many caddis worms burrow into the mud bottom and endure the drought as best they can.