Mudskippers - bài 2

Mudskippers are small four inch long fish which are found in Borneo as well as peninsular Malaysia
and other parts of Asia. They can crawl on land and live up to week without water. Mudskippers are
found in mudflats that spend a great deal of time out of water. There are the only fish that feed, court
and defend their territories on land. Residing in Old World mangrove swamps and muddy estuaries
from West Africa to Papua New Guinea and Australia, they spend about half their time on land and
can live up to week without water. The largest species reach lengths of about 20 centimeters.
Mudskippers are somewhat similar to the first creatures that moved from the seas to land and
evolved into amphibians, reptiles, dinosaurs, mammals and other terrestrial animals. Most species
feed on plankton and algae. Some feed on worms, crustaceans and insects and other food and
small animals they can extract from the mud.
Mudskippers can breath on both land and in the water. Like all fish they have gills. But what makes
them unique are the little chambers they have outside their gills which entrap water and enables
them to breath on land, sort of like a scuba tank in reverse. To breath in this way they need to
regularly fill their mouths with water. They can also absorb oxygen through their skin like a frog does
but to do this they need to keep their skin wet and often roll around in the mud to achieve that end.
Mudskippers have relatively large, funny-looking, protruding bug eyes. These eyes are so well
adapted for seeing on land, the ability to see in water is greatly diminished. Below their eyes are
small cups that hold water. As their eyes become dehydrated they retreat for a time into the cups,
which remoisten them.
There are three main kinds of mudskippers. The smallest ones spend most of their time in the water.
They usually hang out at the water's edge sifting for worms and crustaceans. Medium size ones
spend their time in the mid-tide areas of swamps. They are solitary, feed almost exclusively on algae
and sometimes build mud walls to defend their territory. The third and largest kind hangs out in
mudflats close to shore. It is a carnivore and feeds mostly on small crabs.

Đăng nhận xét

0 Nhận xét