Essential Fish Biology

This book summarizes the basic features of living fish. It is introduced by a chapter on the diversity of a group which has over 30,000 species, the largest within the vertebrates, describing the classification systems used for them and the variety of their habitats and morphology. Thereafter the physiology of fish is described and discussed initially by categories such as the outer boundary (the skin), the circulatory system, food processing, reproduction, hormones as integrators and controllers, the nervous system and the very complex set of sensory receptors including the eyes, ears, lateral line and electro-receptors. Unusual structures, adaptations and behaviours reveal the breadth of fish lifestyles from deep-ocean to shallow reef habitats, with both fresh water and marine margins favouring some near-terrestrial forms even emerging to spawn. With enormous ranges of size, shape and lifecycles, fish are capable of extreme longevity and amazing adjustments to their environment, including colour change, light emission by photophores and sporadic hermaphroditism (both sexes in one individual). The use of fish types by scientists is discussed. Referenced throughout, the scope of the book includes reviews of historically important and recent discoveries and some speculation on the future for fish and fish conservation. Appendices are provided to give in-depth information on some topics, including material briefly describing practical procedures, relevant to experimentation and aquaculture, which may prompt further investigation. The glossary with explanations of terms, and the copious illustrations help understanding of this complex subject area.