''Trichonotus arabicus'', the Arabian sand diver, is a shallow-water, marine

perciform Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means "perch-like". Among the well-known members of this group are perches and darters (Percidae), and also sea ...

fish in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Trichonotidae. It is native to the western Indian Ocean, the

Gulf of Oman The Gulf of Oman or Sea of Oman ( ''khalīj ʿumān''; ''daryâ-ye omân''), also known as Gulf of Makran or Sea of Makran ( ''khalīj makrān''; ''daryâ-ye makrān''), is a gulf in the Indian Ocean that connects the Arabian Sea with th ...

and the

Persian Gulf The Persian Gulf, sometimes called the Arabian Gulf, is a Mediterranean seas, mediterranean sea in West Asia. The body of water is an extension of the Arabian Sea and the larger Indian Ocean located between Iran and the Arabian Peninsula.Un ...

Description

The Arabian sand diver is a somewhat compressed, elongated fish growing to a maximum length of about . The head is pointed with a slightly oblique mouth and a projecting lower jaw. A fringe of

papillae Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Papilla (worms), small bumps on the surface of certain worms * Basilar papilla, a sensory organ of lizards, amphibians and fish * De ...

can be seen along the lip when the mouth is closed. The eyes are small and are set close together near the top of the head. The dorsal fin has 3 to 4 spines of nearly equal length, and 44 to 47 soft rays. The anal fin has a single spine and 36 to 39 soft rays. The dorsal and anal fins bear a row of small yellow spots. The caudal fin is rounded. Males are generally larger than females and have a longitudinal row of about fourteen brown blotches running along the body, and three rows of very small pale blue spots with dark edges. Females have an indistinct dark line running just above the

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

Distribution

The Arabian sand diver is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the western Indian Ocean, the Gulf of Oman and the Persian Gulf. It is a

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer o ...

fish found close to the sandy seabed at depths of up to .

Behaviour

The Arabian sand diver is found in small groups feeding on

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

just above the seabed. When alarmed, the fishes dive into the sand and remains stationary with just the upper parts of their head protruding from the sediment. If further disturbed, they erupt from the sand and swim a short distance before submerging themselves again. Males have a harem of females. Courtship includes the erection of the dorsal fin and the lowering of the pelvic and anal fins.

References

{{Taxonbar, from=Q5105057 Trichonotus Fish described in 1994 Taxa named by John Ernest Randall