Buying an Aquarium for a Child or Teen in Melbourne Buying an Aquarium for Child or Teen in Melbourne | Page 16

Fish, by definition and almost without exception, are cold-blooded vertebrates. This means
that they remain at approximately the same temperature as the water surrounding them.
In contrast to the mammals who are water dwelling such as the Whale or Water Rat, which
like ourselves, usually maintain a much higher internal temperature than the water that
surrounds them when, even though the water may be a much colder temperature than a
mammal could otherwise survive. When the water becomes too...
 How are Freshwater Aquarium Fish and Humans Similar?
Aquarium fish share with Humans and other mammals the possession of a backbone, or
vertebral column. Fish are built on the same fundamental plan, having the same basic
system of bones and organs as mammals. Even more surprisingly, in many cases, some
species of fish exhibit parental behavior, express a sense of family, show signs of
recognition to specific humans and even exhibit signs of emotion. There is much we have
yet to learn about aquarium fish, but they are not just decoration, they are...
 The Basics of the Freshwater Fish Body
 Internal organs
There are many exceptions to the rule in the world of fish, as there are in the world of the
mammal but, in general fish, the common fish found in freshwater aquariums are standard
anatomy.
The fish body is composed mainly of a large lateral muscle on each side of the backbone,
divided by sheets of connective tissue into segments corresponding to the vertebrae. This
anatomy can be seen in almost any fish cooked in a restaurant or pictured in a book. This is
the main organ for swimming.
 Skin and scales
Fish do have skin which is covered in scales, and that skin can have skin conditions, and be
affected by sunlight, damaged by sharp objects and protects the internal organs. The skin
may be naked, or it may be covered by scales or by bony plates which in turn have an outer
layer over them.
 Fins
Fish in almost all cases have two paired and three unpaired fins. The paired pectoral and
pelvic (ventral) fins correspond, respectively, to the arms and legs of human beings and
connect with bony girdles in the body which correspond to our own pectoral and pelvic
girdles.
 Air (Swim) Bladder