Barred Mudskipper

The barred mudskipper is an amphibious goby in the family Oxudercidae (formerly grouped within Gobiidae), genus Periophthalmus, renowned for its ability to move and forage out of water. It is widely distributed across mangrove and mudflat habitats of the Indo-Pacific, from East Africa through South and Southeast Asia to northern Australia and the western Pacific. As one of the most wide-ranging mudskipper species, it is frequently used in studies of fish air-breathing and amphibious adaptation. The species is common throughout its range and not considered threatened, though it depends heavily on the health of mangrove ecosystems, which face ongoing habitat pressure in parts of its range.

The barred mudskipper has an elongated, cylindrical, brownish-gray body marked with faint vertical dark barring along the flanks.

• Bulging, frog-like eyes set high on top of the head, allowing vision above water
• Large, muscular pectoral fins used like limbs to crawl and hop across mud
• First dorsal fin tall and often marked with pale blue spots or edging
• Skin kept moist for cutaneous respiration when out of water

It can be distinguished from the larger giant mudskipper by its smaller size and more slender build, and from the similarly named blue-spotted mudskipper by its fainter, less contrasting body barring.

Barred mudskippers inhabit intertidal mudflats, mangrove forests, and estuarine banks throughout the Indo-Pacific, from the eastern coast of Africa through the Indian subcontinent, Southeast Asia, and northern Australia to Pacific islands. They live at the water's edge, alternating between shallow pools, mud burrows, and exposed mud surfaces during low tide. The species is highly tolerant of fluctuating salinity, typical of brackish estuarine and mangrove environments, and can survive extended periods out of water thanks to cutaneous and buccal respiration. They dig burrows in soft mud that provide refuge from predators and desiccation.

Barred mudskippers are highly active during low tide, when they emerge from the water to forage, bask, and defend territory directly on exposed mud, using their strong pectoral fins to crawl, skip, and even leap short distances. They are territorial, with males often performing visual displays involving raised dorsal fins to attract mates or warn off rivals. Diet consists mainly of small invertebrates such as crabs and insects, along with algae and detritus scraped from the mud surface. Breeding involves males excavating and guarding a burrow in the mud, where eggs are laid and cared for until hatching. As both predator and prey within mangrove ecosystems, they are an important link in intertidal food webs.