Habitat Selection by Aquatic Invertebrates

Abstract

Publisher Summary This chapter focuses on habitat selection by aquatic invertebrates. It explains why animals are found in certain habitats and not in others, and it is restricted to a consideration of habitat selection by marine and freshwater invertebrates as revealed by experimental analysis. Habitat selection is essentially the relationship between behavior and environment, and it largely determines the local distribution of animal species. On the larger scale of geographical distribution, it is as yet uncertain how important habitat selection is, although it almost certainly plays a significant role. The chapter discusses the physical and chemical environment of intertidal animals, marine animals, freshwater animals, and interstitial animals. The reactions of animals to their biological environment and the part these play in habitat selection are very varied. Animals are continuously assessing the suitability of their environment and moving from place to place so that they can take best advantage of the range of conditions available to them. The behavioral mechanisms by which animals select their habitats, light reactions, gravity responses, gregariousness, and so on, have been covered in the chapter. Habitat preferences may remain fixed throughout the life span of an animal, or they may alter depending upon its physiological state, its age, its previous experience and learning, or its past and present environment. The marked variation in behavior shown by individuals of some species has been discussed along with the possible ways in which animals may colonize new habitats and to the part habitat selection might play in the origin of new species.