I can’t believe I haven’t blogged about mudskippers yet. They are such a unique and weird group of fish that they definitely deserve a spot on this blog. After all, any fish that skips around on land without a care in the world is worth writing about.
There are about 41 species of mudskipper, in the subfamily Oxudercinae. They are found in coastal areas of Africa and the Indo-Pacific. Thanks to their ability to do well out of water, mudskippers are able to thrive in changing habitats, such as mangrove forests and intertidal areas. They can be found in freshwater, saltwater, or brackish water, depending on the species.
Mudskippers vary in size from 7 cm to 25 cm, again, depending on the species. As their name suggests, mudskippers are often found in muddy areas. To help camouflage themselves in these habitats, they are often a simple brown colour. Their eyes are located at the top of their heads, which allows mudskippers to see both above and below water at once. The eyes can move independently of one another, giving the fish a broad field of vision.
As you can imagine, mudskippers have to have a number of adaptations to make their lifestyle viable. One of the most notable of these are mudskippers’ pectoral fins. These fins are long and have a kind of ‘joint’ in them, which allows the fins to act like legs. Very muscular tails also help mudskippers move on land; using their tails to propel themselves, mudskippers can ‘skip’, launching themselves up to 60 cm.
The second set of adaptations mudskippers possess have to do with breathing. Like amphibians, mudskippers can breathe through their skin, as well as through the lining of their mouths. This type of breathing only works when the skin and mouth are wet, which means mudskippers can’t survive in non-humid environments. When mudskippers leave water for land, they fill their gill chambers with water, which gives them an extra source of oxygen while on land.
Mudskippers dig burrows while they are on land, to keep themselves safe from predators, to thermoregulate, and for reproductive purposes. The burrows are dug so at least part of them is submerged, but often this water has very low oxygen concentrations. Mudskippers work around this by gulping oxygen and releasing it into the burrow.
Male mudskippers display to attract females, using a combination of manly push-ups and acrobatic leaps into the air. If a female mudskipper is impressed by a male’s antics, she will waltz back to his burrow, and the two will mate. The female then lays her eggs on the roof of the burrow, and leaves. Male mudskippers are responsible for guarding and aerating the eggs.
It never ceases to amaze me how adaptable animals are. Fish that spend a significant portion of their time out of water have got to be some of the coolest animals around. I’m a big fan of them, anyway.
Cover image credit: H. Krisp via Wikipedia