Mudskippers are fishes. Amphibious, walking, climbing, air-breathing fishes. Weird-looking, beady-eyed, charismatic, and cute, mudskippers are some of the neatest creatures on earth. When I was an intern at the New York Aquarium, I took it upon myself to learn all I could about these poorly-understood gobies. I’m not generally much of an armchair ichthyologist, but read along and hopefully you will understand why mudskippers in particular continue to pique my interest.
Mudskippers at the NY Aquarium. Photos by me.THE AMBLING FISH
The most immediately unique trait of the mudskipper is that it can walk on land. Far from quadrupedal, it drags itself along like a true seal with powerful, modified front fins. Flexing and jumping, mudskippers can move quite quickly on land when they need to.
Mudskippers can also climb the mangroves and things that grow in their swampy habitats. The adorable, tiny, so-called “Indian” mudskippers (Periophthalmus sp.) housed at the New York Aquarium can be seen clinging to their fake mangroves as well as to the walls of their tank. A mudskipper’s ability to climb and stick to surfaces is due to its muscular pectoral fins and also to a suction disk located on its underside below its head.
Mudskippers are so well adapted to their amphibious lifestyle that some can spend up to 90% of their lives out of the water!
BURROWING BEHAVIOR
Like many species that live in tidal zones, the mudskipper’s daily routine is governed by a predictable tide. While the tide is low, despite the threat of predation from seabirds and terrestrial animals, mudskippers forage along the mudflats for small crustaceans and fishes. When the tide is high, however, they stay hidden from predatory fish inside deep burrows they’ve dug in the mud. Mudskippers have evolved an ingenious way of keeping their burrows oxygenated while completely submerged, sometimes for several hours. They literally gulp air from the surface, and then carry it down into a specially crafted chamber where the air is released, forming a bubble at the top of the chamber. Research suggests that mudskippers use this same behavior to keep their eggs oxygenated in nursery chambers.
The burrow is a mudskipper’s refuge and a highly defended marker of his territory. Mudskipper species can be highly territorial. The Indian mudskippers at the New York Aquarium are not nearly as territorial as other species, and can be kept in close quarters together. Occasionally an individual will show territorial aggression, however, by lifting its brightly colored dorsal fin as a warning to a nearby individual.
During breeding season, males of some species show off their decorated burrows and do elaborate dances and flips to attract females. Little is known about mudskipper breeding, however.
Look at that face! Photo by me.
CLASSIFICATION AND TAXONOMY
CLASS: Actinopterygii (ray-finned fishes)
ORDER: Perciformes (perch-like fishes; the largest order of vertebrates!)
FAMILY: Gobiidae (gobies)
SUBFAMILY: Oxudercinae (mudskippers)
MANGROVE HABITAT CONSERVATION
Mudskippers around the world are threatened by habitat loss. Mangrove swamps not only provide valuable habitat for a variety of fascinating animals, but they also serve as natural buffers to erosion, storm surges and tsunamis, and also trap pollutants. Coastal human populations around the world benefit from strong mangrove ecosystems, and the loss of these ecosystems is tangibly affecting many regions.
SOURCES AND ADDITIONAL READING
http://en.wikipedia.org/wiki/Mangrove
http://species.wikimedia.org/wiki/Oxudercinae
http://www.naturalhistorymag.com/0902/0902_feature.html
http://newyorktails.com/mudskippers.htm
You can also see mudskippers (Periophthalmus barbarus) at the Bronx Zoo!
