Feeding and Responses to Food Abundance

Abstract

Marine heterotrophs have evolved a very large variety of feeding mechanisms to obtain their rations, and any given species usually makes use of several feeding mechanisms (Pandian, 1975). Heterotrophs may use organic matter dissolved in water or on larger particles. Dissolved food may be taken up through the body or cell surface, as occurs in microorganisms, many invertebrate parasites, and pogonophorans. Other consumers take up fluids through their mouth, as in the case of some nematodes, trematodes, leeches, parasitic copepods, and young mammals. Dissolved food is also obtained by some heterotrophs from their endosymbionts, as in the case of zooxanthellae in corals and other cnidarians, and sulfur bacteria in some pogonophorans and bivalves.