Fish are extremely successful vertebrates. Because of a long and
divergent history they are now found in almost every conceiv- able
aquatic habitat. This radiation has been accompanied by great diversity
in structure, physiology, and behaviour. Despite this variability, fish
must solve a number of basic problems that are common to all animals.
The most important of these are: (1) to find and ingest appropriate
food; (2) to avoid predation; and (3) to reproduce. The main purpose of
this book is to describe the variety of behavioural strategies that fish
use in coping with these problems. My approach has been to draw together
material from both field and laboratory work that is widely scattered in
the litera- ture. The major emphasis is on field studies, since my main
concern is with adaptive solutions to problems, and I believe these are
most likely to be correctly perceived by workers who are familiar with
the natural ecological setting of their animals. Of course, many details
of behaviour cannot be seen and quantified adequately in the field, and
therefore I have not ignored laboratory studies. However, even here I
have concen- trated on work that illustrates the variety of solutions
that fish use to solve the three basic problems. Much important work,
for instance on causation, development, and learning, is not included.