Fish are aquatic craniate animals which lack limbs with digits but
possess gills. Some of their common types are bony fish, hagfish,
lampreys and cartilaginous fish. These are cold blooded animals with the
exception of active swimmers like sharks and tuna. Fish communicate with
each other by means of acoustic communication. This involves production
of stridulatory sounds and non-stridulatory sounds. Fish generate these
sounds by moving parts of their skeletons or using a dedicated organ
like the swimbladder. They exist in most of the aquatic environments
ranging from high mountain streams to hadopelagic zones. Fish have
streamlined bodies and have two sets of paired fins. Most of them are
covered with scales and lay eggs. This book presents the complex subject
of fish biology in the most comprehensible and easy to understand
language. Its extensive content provides the readers with a thorough
understanding of the subject. This textbook is appropriate for students
seeking detailed information in this area as well as for experts.