Let's speak about fish, the animal group that includes the eel, the pet hero of the story An eel in the aquarium.
But before reading further, watch the video my "boss" created for you on this animal theme. Most of its clips were taken at the
Lisbon Oceanarium, which is one of the largest and most beautiful aquaria in the world.
Is the body of fish covered with hair or feathers?
The body of a fish is not covered with hair as in the case of mammals; nor with feathers as in the case of birds. Fish have their body covered with scales.
Are fish cold-blooded or warm-blooded animals?
A fish has gills instead of lungs, and its heart is only divided in two parts; this is the reason why fish are cold-blooded animals,
in opposition to mammals and birds that have their heart divided into four parts and are called warm-blooded animals.
How do fish move in water?
Fish move in water with their fins: they have paired and impaired fins.
Are fish vertebrate or invertebrate animals?
Fish are vertebrate animals. As to their skeleton, it can have a bone or a cartilaginous structure.
What are aquaria for?
Some fish - like eels, sardines, trouts, sole - are sold in the fish market where you can see them in their original size.
But fish like sharks, cods, rays are usually cut in slices before being sold, due to their big size.
As it is not easy to see these animals in their natural living environment in the fish market, man built aquaria to that purpose.
Is the open sea the only natural environment for fish?
You might like to know that the open sea is not the only natural environment for fish; some prefer the river waters;
and others live both in sea and river waters, like the salmon and... the eel! Oh yeah!
Eels live in fresh water, but they go to the open sea to lay their eggs.
What is aquatic fauna?
Every animal (mammal, bird, reptile) living in or near a water environment (sea or river) belongs to the aquatic fauna
no matter if they are mammals, birds, reptiles or amphibians:
dolphins, ducks, penguins, otters, flamingos, crocodiles, frogs or many others.
Did you know that...
the largest fish in the world is the whale shark?
It is nevertheless a harmless fish that feeds on small fish and planton.
