The mudskipper is an unusual creature, a member of the goby fish family that has adapted to live a largely terrestrial life. Found predominantly in the intertidal zones of tropical and subtropical regions, these fish navigate the harsh environments of mudflats and mangrove forests across the Indo-Pacific and parts of Africa. Unlike most fish that are confined to water, the mudskipper is an amphibious marvel, spending up to three-quarters of its time out of the water.
Anatomy of Mudskipper Teeth
Mudskippers possess teeth, which are highly specialized structures adapted to their unique carnivorous lifestyle. These teeth are typically small, sharp, and conical, primarily positioned on the upper and lower jaws. In certain species, such as those in the Periophthalmus genus, the front teeth can be notably prominent and canine-like, projecting forward from the jawline.
The teeth are utilized primarily for grasping and securing prey rather than for extensive chewing or grinding. Beyond the oral cavity, some species also possess a set of pharyngeal teeth located deeper in the throat. These accessory teeth help in processing food by acting as a grinding mill.
Feeding Behavior and Diet
The mudskipper’s feeding strategy is linked to its dentition and amphibious environment. These fish are opportunistic carnivores, with a diet consisting mainly of small invertebrates found on the mudflats, such as insects, small crustaceans, and worms. Capturing prey on a terrestrial surface requires a specialized technique, as the typical suction feeding mechanism used by aquatic fish does not work efficiently in air. The mudskipper overcomes this challenge through a rapid lunge combined with a unique oral adaptation.
When hunting, the fish uses its specialized pectoral fins to lift its anterior body, positioning its mouth parallel to the substrate. It then uses its teeth to swiftly grasp the prey, which is often secured between its jaws. To assist in ingestion on land, the mudskipper employs a mechanism sometimes referred to as a “water tongue.” This involves holding a small amount of water in its buccal cavity, which is then used to create a momentary suction force to pull the captured food further into the mouth for swallowing.
Amphibious Adaptations
The mudskipper’s ability to remain active for extended periods outside of water is supported by several biological features. One significant adaptation involves its method of respiration. While they retain their gills, mudskippers can absorb oxygen directly from the air through cutaneous respiration, which involves uptake through their moist skin and the lining of their mouth and throat. This process requires the fish to keep its body surface wet, which it manages by periodically rolling in wet mud or returning to water.
Further supporting terrestrial breathing, mudskippers possess enlarged gill chambers that can hold a bubble of air and water when they are on land. This trapped reservoir allows for continued oxygen extraction. For movement, their pectoral fins are highly modified, featuring a muscular, jointed structure that functions similarly to a limb. This allows the fish to perform a characteristic “crutching” motion, effectively walking or crawling across the mudflats. They can also execute a powerful “skipping” or leaping movement by flexing their muscular tail.