. Fresh-water biology. Freshwater biology. THE AQUATIC VERTEBRATES 1057 prey and deliberately pick it from the water. Such are provided with teeth either in their mouths or in their gullets. Another series probably including the spoonbill catfish take in large quanti- ties of water and strain the plankton from it. They have weak teeth or none and specially-adapted gill rakers for straining the water. The various darters, a peculiar American product, are all Ht- toral. They rest on their pectorals on the bottom in shallow water. With head erect and eyes protruding they are ready for anything th
. Fresh-water biology. Freshwater biology. THE AQUATIC VERTEBRATES 1057 prey and deliberately pick it from the water. Such are provided with teeth either in their mouths or in their gullets. Another series probably including the spoonbill catfish take in large quanti- ties of water and strain the plankton from it. They have weak teeth or none and specially-adapted gill rakers for straining the water. The various darters, a peculiar American product, are all Ht- toral. They rest on their pectorals on the bottom in shallow water. With head erect and eyes protruding they are ready for anything that moves within their range of \ision. They are found among weeds and gravel, chiefly in flowing water so shallow that. Fig. 1547. Johnny Darter, Bohosoma nigrum Rafinesque. Actual size, 55 mm. long. the surface is rippled. Associated with them, or in places similar to these, in favorable locahties, are miller's-thunibs. The pirate perch and trout perch should probably also be placed here. Other bottom fishes with sucker mouth and elongate alimentary canal are found over mud bottoms. These include Campostoma, suckers, carp, and sturgeon in North America. In tropical America their place is taken by peculiar armored relatives of the catfishes, the Loricariidae. Lastly, the large, predacious fishes treat the smaller fishes as they in their turn treat the plankton. Here be- long the muscalonge, the pickerels, salmon trout, and the basses. Our nocturnal catfishes and the ubiquitous eel are omnivorous. They take what they can. Everything that tastes or moves and is within reach is food for the nocturnal catfish. Some bhndfishes planted in a pool had a way of disappearing that was mysterious, until the pool was drained and the sardonic catfish, lurking under a rock and found in possession of the last bhndfish partly digested, solved the mystery. Fishes are adapted to their food in structure as well as Please note that these images are extracted from scanned page images that ma
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
