The Gangetic whiting, ''Sillaginopsis panijus'' (also known as the flathead sillago), is a species of

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 ...

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 * ...

and estuarine 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 ...

. It is the most distinctive Asian member of the family due to its flattened head and trailing dorsal fins. Although first described in 1822, it was not placed in its own genus until 1861 when Theodore Gill erected ''Sillaginopsis'', a genus which is still monotypic. Gangetic whiting are of minor commercial importance along the Southeast coast of the Asian continent where it inhabits protected areas.

Taxonomy and naming

The Gangetic whiting is the only species of the genus ''Sillaginopsis'', which itself is one of three genera the family

, containing all the smelt whitings. The Sillaginidae are part of the Percoidei, a suborder of the order Perciformes. The Gangetic whiting was originally named ''Cheilodipterus panijus'' in 1822 by

Francis Buchanan-Hamilton Francis Buchanan (15 February 1762 – 15 June 1829), later known as Francis Hamilton but often referred to as Francis Buchanan-Hamilton, was a Scottish physician who made significant contributions as a geographer, zoologist, and botanist whil ...

from a holotype taken from the Ganges estuary in India. The species was further examined by Gill in 1861 in the first review of the family, entitled "Synopsis of the Sillaginoids", which led to the creation of the genus ''Sillaginopsis''. This new classification changed the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

to the currently accepted ''Sillaginopsis panijus''.

Description

The distinct appearance of the Gangetic whiting makes it the easiest of the smelt whitings to identify. The

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...

of the species is highly depressed, like that of the flatheads, with very small eyes well constricted by the orbits. The first dorsal fin contains ten spines including a large trailing second spine; the second dorsal fin has one spine and 25 to 27 soft rays. 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 ...

has two spines and 24 to 27 soft rays. There are 84 to 90

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 the species has a total of 42 vertebrae. The species is known to grow to a length of 44 cm. Another unique feature of this species is its severe reduction or even absence of a

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 ...

, which all other members of the family Sillaginidae possess. The Gangetic whiting also has a small mouth with a much shorter lower jaw than upper jaw, with the two

anterior 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 ...

most teeth larger than the rest.

Distribution and habitat

The Gangetic whiting is found on the southern Asian coast from Puducherry in the east, northward along the Coromandel Coast and the Ganges delta,

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

, Malaysia and occasionally as far south as the Indonesian archipelago. The species is often found on silty or

mud A MUD (; originally multi-user dungeon, with later variants multi-user dimension and multi-user domain) is a Multiplayer video game, multiplayer Time-keeping systems in games#Real-time, real-time virtual world, usually Text-based game, text-bas ...

dy substrates in shallow, open

bay A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a Gulf (geography), gulf, sea, sound (geography), sound, or bight (geogra ...

s and estuaries along the coast. Juveniles usually migrate into the upper reaches of estuaries for protection against predation by larger species.

Biology

Gut content analysis has found the Gangetic whiting consumes numerous small fish,

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

and planktonic crustaceans and

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

, with its small mouth size restricting the size of food portions. The Gangetic whiting is the only known species of fish to host the intestinal parasite ''

Dichelyne alatae ''Dichelyne alatae'' is a species of nematode, described on the basis of the worms recovered from the intestine of the whiting, '' Sillaginopsis panijus'' from the estuary of the Hooghly River at Kalyani, West Bengal, India. ''Dichelyne alatae' ...

'', found in specimens in West Bengal, with a number of other parasites identified from it. Otolith and size-age composition studies by Krishnayya (1963) of the commercial catches from the

Hooghly River The Bhagirathi Hooghly River (Anglicized alternatively spelled ''Hoogli'' or ''Hugli'') or the 'Bhāgirathi-Hooghly', called the Ganga or the Kati-Ganga in mythological texts, is the eastern distributary of the Ganges River in West Bengal, Indi ...

estuary and found that ''S. panijus'' probably spawns twice a year during the periods of November to February and August to September. The juveniles migrate toward the upper reaches during March and April and during December where they remain for two to three months. Sexual maturity is attained at a length of about 120 mm.

Relationship to humans

A local

fishery Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...

exists along the coast of the Bay of Bengal primarily near or on the river deltas, with commercially important fish captured by nets and longlines in the Hooghly and Ganges delta. The Gangetic whiting 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 ...

, rarely making its way to overseas markets. Juvenile ''Sillaginopsis panijus'' are also occasionally traded as brackish water aquarium fish.

References

{{Taxonbar, from=Q3229859 Sillaginidae Fish of South Asia Fish described in 1822