Kei goby

The Kei goby (scientific name: Priolepis semidoliata) is a species of marine ray-finned fish belonging to the family Gobiidae, the gobies. It is commonly known as the Half-barred goby or Half-bar goby, a name referencing its distinctive markings. The common name "Kei goby" likely originates from its historical association with the Kei Islands, an archipelago in Indonesia, where it was first described or is commonly found.

Description

The Kei goby is a small fish, typically reaching a maximum standard length of about 3 to 4 centimeters (1.2 to 1.6 inches). Its body is generally slender and compressed. A key identifying feature is its coloration: the anterior (front) half of its body is marked with several dark, vertical bands or saddles that extend from the dorsal (top) side down to the lateral line, contrasting with a paler background. The posterior (rear) half of the body, including the caudal fin (tail fin), is often plain or with much fainter markings. Like other members of the Priolepis genus, it possesses two distinct dorsal fins.

Habitat and Distribution

Priolepis semidoliata is a reef-associated species. It is typically found in tropical marine waters of the Indo-Pacific region. Its distribution spans from the Indian Ocean, including areas like the Maldives and Andaman Sea, eastward through Southeast Asia, including Indonesia, the Philippines, and Papua New Guinea, to the western Pacific Ocean, reaching as far as Micronesia and parts of Polynesia. It inhabits coral reefs, often preferring rubble areas, crevices, or beneath ledges, at depths generally ranging from shallow waters down to about 40 meters (130 feet). Its small size and secretive nature often make it difficult to spot.

Behavior and Ecology

Like many small gobies, the Kei goby is often solitary or found in pairs. It is known to be quite shy and will quickly retreat into the safety of coral crevices or rubble when approached. Its diet likely consists of small benthic invertebrates, typical for reef-dwelling micro-predators. Its cryptic coloration provides camouflage within its complex reef environment, helping it to avoid predators.