Fish Feeding

Just as a fish’s body shape can tell you a lot about its swimming habits, its mouth can tell you something about its feeding habits. Bottom feeders have downward pointing mouths, while surface feeders have mouths that point upward. For most fish, the mouth is at the end of the snout.

The size of the mouth is usually directly related to the size of the fish’s preferred food. For example, large predatory fish like Oscars have larger oval mouths for consuming smaller fish. Fish that normally feed on small aquatic invertebrates, like Neon Tetras, have smaller mouths. Some tropical freshwater fish have specialized mouths for specialized feeding strategies. Plecostomus fish, for example, have special sucking mouths for bottom feeding.

Freshwater tropical fish have a relatively straightforward digestive system, which varies from species to species. In general, food passes from the mouth, down the esophagus, to the stomach, and through the intestine; wastes are expelled from the anal vent. However, several species lack true stomachs and instead have elongated, super-coiled intestines.