The Thai whiting, ''Sillago intermedius'', is a species of coastal

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

fish of the smelt-whiting family

Sillaginidae The Sillaginidae, commonly known as the smelt-whitings, whitings, sillaginids, sand borers and sand-smelts, are a family of benthic coastal marine fish in the order Perciformes. The smelt-whitings inhabit a wide region covering much of the Indo ...

. The Thai whiting ranges from the west coast of India to the

Gulf of Thailand The Gulf of Thailand, also known as the Gulf of Siam, is a shallow inlet in the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. It is around in l ...

in the east, inhabiting silty substrates in shallow waters. First identified in 1977 from a

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository ...

found in a fish market, the species has had little research performed on its biology, and is frequently misidentified as ''

Sillago sihama The northern whiting (''Sillago sihama''), also known as the silver whiting and sand smelt, is a marine fish, the most widespread and abundant member of the smelt-whiting family Sillaginidae. The northern whiting was the first species of sillagi ...

'' or ''

Sillago maculata The trumpeter whiting, ''Sillago maculata'', (also known as the winter whiting or diver whiting) is a common species of coastal marine fish of the smelt-whiting family, Sillaginidae. The trumpeter whiting is endemic to Australia, inhabiting the ...

'' Thai whiting are commonly caught by fishermen throughout their range and are marketed fresh locally.

Taxonomy and naming

The Thai whiting is one of 29 species in the genus '' Sillago'', which is one of three divisions of the smelt whiting family

. The smelt-whitings are Perciformes in the

suborder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

Percoidea. The species was first recognized and named ''Sillago intermedius'' by Wongratana in 1977 after a number of unknown sillaginid individuals were found in a Thai fish market whilst Wongratana was collecting specimens of sillaginids to be sent to McKay for his review of the Sillaginidae. He based his description on a

taken from the east coast of Thailand in 1977, which was allocated to be the holotype. The species has been subsequently misidentified as ''Sillago maculata'', as the blotches on the species are fairly similar.

Description

As with most of the genus ''Sillago'', the Thai whiting has a slightly compressed, elongate body tapering toward the terminal mouth. The body is covered in small ctenoid scales extending to the two rows of cheek scales and head. The first dorsal fin has 11 spines and the second dorsal fin has 1 leading spine with 21 to 22 soft rays posterior. The

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is similar to the second dorsal fin, but has 2 spines with 21 to 22 soft rays posterior to the spines. Other distinguishing features include 67 to 70

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 epithelial ...

scales and a total of 34 vertebrae. The species has a known maximum length of 20 cm. The

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...

has two anterior extensions which extend forward and diverge before terminating above the auditory capsule. Two lateral extensions commence

anteriorly Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

, sending tubules to the anterior and extending below the abdominal wall adjacent to the swimbladder. There are also two posterior extensions which project into the post-coelomic region. The morphology of the swim-bladder is quite similar to ''S. sihama'', but the tubules are very simple, unlike ''S. sihama'' which has complexly folded extensions. The Thai whiting is a pale silvery colour, being darker on top and lighter below. The top of the snout is blackish, while the

opercle The operculum is a series of bones found in bony fish and chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contains four bon ...

, preopercle and preorbital are bright silver. The sides of the body below the lateral line have a longitudinal row of 8 or 9 dark blotches. The back also has a row of dusky blotches. The caudal fin has darker upper and lower rays, with all other fins

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

in appearance.

Distribution and habitat

As its name suggests, the Thai whiting occurs predominantly in Thailand where it ranges the Gulf of Thailand, extending westward to the west coast of the Indian subcontinent, apparently having a fairly scattered distribution. The Thai whiting is a shallow water,

inshore A shore or a shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. In physical oceanography, a shore is the wider fringe that is geologically modified by the action of the body of water past a ...

species which inhabits open silty substrates at depths of 0 to 10 m, occasionally entering estuaries. Nothing else known of its biology.

Relationship to humans

Like other sillaginids, the Thai whiting is taken on a small scale by fishermen throughout its range, where it is sold fresh in local

markets Market is a term used to describe concepts such as: * Market (economics), system in which parties engage in transactions according to supply and demand * Market economy *Marketplace, a physical marketplace or public market Geography *Märket, a ...

. It is often not differentiated form other sillaginids due to its close resemblance to both ''S. sihama'' and ''S. maculata''.

References

External links

Thai whiting at Fishbase
{{Taxonbar, from=Q2303228 Sillaginidae Taxa named by Thosaporn Wongratana Fish described in 1977