Mudskipper

Mudskippers are a group of amphibious gobies within the family Oxudercidae, including species such as Periophthalmus barbarus, that are unusual among fishes for spending the majority of their time out of water. They are native to mangrove forests, mudflats, and tidal creeks across the tropical and subtropical Indo-Pacific and the West African coast. Mudskippers have evolved a suite of adaptations for life on land, including the ability to breathe through their skin and moist gill chambers, and muscular pectoral fins used for crawling and hopping across exposed mud. They are common and ecologically important members of mangrove and intertidal ecosystems throughout their range.

Mudskippers have an elongated, cylindrical body typically 10-25 cm long, usually mottled brown, olive, or gray to match muddy substrate.

Key identification features:

• Large, bulging eyes set high on top of the head, able to move independently and retract into sockets
• Muscular, limb-like pectoral fins used to crawl, skip, and climb
• A tall, often colorful sail-like dorsal fin, sometimes spotted, that may be raised in display
• Smooth, thick, moisture-retaining skin
• Fused pelvic fins in many species forming a small sucker-like disc

Their ability to remain active out of water while breathing air, combined with the periscope-like eyes, immediately distinguishes mudskippers from all other fish found in the same habitat.

Mudskippers inhabit intertidal mudflats, mangrove forests, and estuarine creeks throughout the tropical and subtropical Indo-Pacific, with additional species along the West African coast. They are found in the intertidal zone, spending much of the tidal cycle exposed on mud or perched on mangrove roots rather than fully submerged. Mudskippers dig and maintain burrows in soft mud, which provide refuge from predators, protection from desiccation and heat, and a stable microclimate during low tide. They favor brackish water with high organic content and require humid air and damp skin to support their unusual method of cutaneous respiration.

Mudskippers are highly territorial, with individuals or mated pairs defending a burrow and surrounding mudflat area against rivals, often through visual displays involving the raised dorsal fin, open-mouth threats, and chasing. They are active during low tide, when they emerge from the water to feed, patrol territory, and bask, retreating to their burrows or standing water as the tide rises or if disturbed. Mudskippers feed on small invertebrates such as insects, worms, and crustaceans, as well as algae, foraging directly on exposed mud surfaces. Breeding involves males performing jumping and fin displays to attract females, who lay eggs inside the male's burrow, often in an air-filled chamber that the male tends and guards until hatching.