Gangetic whiting | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Spariformes |
Family: | Sillaginidae |
Genus: | Sillaginopsis T. N. Gill, 1861 |
Species: | S. panijus |
Binomial name | |
Sillaginopsis panijus (Hamilton, 1822) | |
Range of Gangetic whiting in dark blue | |
Synonyms | |
Sillago panijus Hamilton, 1822 Contents |
The Gangetic whiting (Sillaginopsis panijus), also known as the Gangetic sillago or flathead sillago, is a species of inshore marine and estuarine fish of the smelt-whiting family, Sillaginidae. 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.
The Gangetic whiting is the only species of the genus Sillaginopsis, which itself is one of three genera the family Sillaginidae, containing all the smelt whitings. The Sillaginidae are part of the Percoidei, a suborder of the order Perciformes. [2]
The Gangetic whiting was originally named Cheilodipterus panijus in 1822 by Francis Buchanan-Hamilton 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 to the currently accepted Sillaginopsis panijus. [3]
The distinct appearance of the Gangetic whiting makes it the easiest of the smelt whitings to identify. The head of the species is highly depressed, like that of the flatheads, with very small eyes well constricted by the orbits. [4] 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 has two spines and 24 to 27 soft rays. There are 84 to 90 lateral line scales and the species has a total of 42 vertebrae. The species is known to grow to a length of 44 cm. [5]
Another unique feature of this species is its severe reduction or even absence of a swim bladder, 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 anteriormost teeth larger than the rest. [3]
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, Malaysia and occasionally as far south as the Indonesian archipelago. [3]
The species is often found on silty or muddy substrates in shallow, open bays and estuaries along the coast. Juveniles usually migrate into the upper reaches of estuaries for protection against predation by larger species. [4]
Gut content analysis has found the Gangetic whiting consumes numerous small fish, benthic and planktonic crustaceans and algae, with its small mouth size restricting the size of food portions. [5]
The Gangetic whiting is the only known species of fish to host the intestinal parasite Dichelyne alatae , found in specimens in West Bengal, [6] 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 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. [7]
A local fishery 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, rarely making its way to overseas markets. [3] Juvenile Sillaginopsis panijus are also occasionally traded as brackish water aquarium fish. [8]
The Sillaginidae, commonly known as the smelt-whitings, whitings, sillaginids, sand borers and sand-smelts, are a family of benthic coastal marine fish historically classified in the order Perciformes, although the 5th edition of Fishes of the World places the family in the Spariformes. The smelt-whitings inhabit a wide region covering much of the Indo-Pacific, from the west coast of Africa east to Japan and south to Australia. The family comprises only five genera and 35 species, of which a number are dubious, with the last major revision of the family in 1992 unable to confirm the validity of a number of species. They are elongated, slightly compressed fish, often light brown to silver in colour, with a variety of markings and patterns on their upper bodies. The Sillaginidae are not related to a number of fishes commonly called 'whiting' in the Northern Hemisphere, including the fish originally called whiting, Merlangius merlangus.
The oriental trumpeter whiting is a widely distributed species of benthic inshore fish in the smelt-whiting family. The species ranges from east Africa to Japan, inhabiting much if the southern Asian and Indonesian coastlines. Its morphology is very similar to other species within the genus Sillago, with a long, compressed body and silvery overall colour. It can be distinguished from its relatives by colour patterns and particularly swim bladder morphology, which helps define most species of Sillago. S aeolus is a benthic predator, consuming a variety of crustaceans and polychaetes. As with most members of the smelt whiting family, it is important to small coastal fisheries in various areas of its range.
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 is unique in having a small body size, deirids posterior to the oesophagus, short and wide caudal alae at the level of cloacal opening, unequal, alate spicules, a shield-shaped gubernaculum, a different number of caudal papillae and a conical tail with spines in its distal region.
The Asian whiting is a species inshore marine fish in the smelt whiting family, Sillaginidae, distributed along the Asian coastline from the Gulf of Thailand to Taiwan. The Asian whiting's appearance is very similar to other closely related species in the genus Sillago, with swim bladder morphology and ray counts of fins the most reliable identifying features. The species inhabits slightly deeper water than many of the sillaginid species its distribution overlaps, forming an important part of the whiting fishery in the countries within its range.
The slender whiting is a poorly known species of inshore marine fish of the smelt whiting family, Sillaginidae that has a distribution limited to the Persian Gulf only. The Slender whiting, like most sillaginids requires careful study to determine its identity, with ray and vertebrae counts as well as swim bladder morphology distinguishing features. This inshore species of fish is commonly taken by fishermen using beach seines and is sold fresh in local markets.
The western trumpeter whiting is a species of marine fish of the smelt whiting family Sillaginidae that is commonly found along the northern coast of Australia and in southern Indonesia and New Guinea. As its name suggests, it is closely related to and resembles the trumpeter whiting which inhabits the east coast of Australia and is distinguishable by swim bladder morphology alone. The species inhabits a variety of sandy, silty and muddy substrates in depths from 0 to 15 m deep, with older fish inhabiting deeper waters. Western trumpeter whiting are benthic carnivores which take predominantly crustaceans and polychaetes as prey. The species reaches sexual maturity at the end of its first year of age, spawning in batches between December and February. The species is taken as bycatch with other species of whiting and shrimps in Australia.
The club-foot whiting, also known as the club-foot sillago or thicken-spined sillago, the only member of the monospecific genus Sillaginopodys, is a coastal marine fish of the smelt whiting family Sillaginidae that inhabits a wide range including west Africa, India and the northern Indonesian Archipelago. The species is unique in the morphology of the pelvic spine and fin, making identification of the species easier than most of its relatives. The species is of minor commercial importance, taken by seine net and marketed fresh throughout its range.
The sand whiting, also known as the summer whiting, yellowfin whiting or blue-nose whiting, is a common species of coastal marine fish of the family Sillaginidae, the smelt-whitings. It is a slender, slightly compressed fish that is very similar to other species of Sillago, with detailed spine, ray and lateral line scale counts needed to distinguish the species between its nearest relative Sillago analis. The sand whiting is distributed along the east coast of Australia from Cape York south to Tasmania, as well as Lord Howe Island and New Caledonia in the Pacific Ocean.
Sillago indica, the Indian sillago, is a poorly known species of coastal marine fish of the smelt-whiting family Sillaginidae. The species was named in 1985, having previously being misidentified as another species of Sillago, S. parvisquamis. The Indian sillago inhabits the coasts of the Indian subcontinent and Oman. Like all sillaginids, it is benthic in nature, living in depths to 30 m where it is caught by fishermen alongside other species of Sillago.
The Japanese whiting, also known as the Japanese sillago or Shiro-gisu, is a common species of coastal marine fish belonging to the smelt-whiting family, Sillaginidae. As suggested by its name, the Japanese whiting was first recorded from Japan in 1843, but has subsequently been found to extend to Korea, China and Taiwan.
The large-scale whiting the only member of the genus Sillaginops, is a poorly understood species of coastal marine fish of the smelt- whiting family Sillaginidae. First described in 1859, the large-scale whiting is known to inhabit shallow waters along the coasts of a number of Indo-Pacific countries including Japan, Indonesia, Philippines and the Solomon Islands. Little is known of the species biology, even though it is of minor importance to fisheries throughout its range.
The trumpeter whiting, 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 eastern seaboard from southern New South Wales to northern Queensland. The species is found in bays, estuaries, coastal lakes and mangrove creeks on silty and muddy substrates in waters ranging from 0 to 30 m deep, occasionally inhabiting sandy and seagrass beds.
The small-eyed whiting is a poorly known species of coastal marine fish of the smelt-whiting family Sillaginidae. The species is known from only two specimens; the holotype collected by Roland McKay in 1985 from a Taipei market, both specimens of which were taken from the waters of Taiwan. Apart from a relatively small eye size, the species is hard to distinguish from other common species of sillaginid taken in the area, and may be a minor part of local fisheries.
The northern whiting, 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 sillaginid scientifically described and is therefore the type species of both the family Sillaginidae and the genus Sillago. The species is distributed in the Indo-Pacific region from South Africa in the west to Japan and Indonesia in the east. The northern whiting inhabits coastal areas to 60 m, but is most often found in shallow water around bays and estuaries, often entering freshwater. It is a carnivore, taking a variety of polychaetes and crustaceans. The species is of major economic importance throughout the Indo-Pacific. It is most frequently taken by seine nets and cast nets and marketed fresh.
The small-scale whiting, also known as the blue whiting, is a species of inshore marine fish of the smelt-whiting family Sillaginidae. The small-scale whiting is very similar in body shape and colour to other species in the genus Sillago, but is distinguished by having 12 or 13 spines in the first dorsal fin compared to 11 in all other species. The species is distributed through parts of the west Pacific Ocean including Japan, Taiwan, Korea and India, inhabiting the tidal flats of major estuaries. It is a benthic predator taking crustaceans, molluscs and annelids. Spawning in the species takes place from May to September, with peaks identified in June and July. The eggs and larvae have been extensively studied in order to distinguish them from the more abundant Sillago sihama. Minor fisheries exist for the small-scale whiting, although it is thought be endangered by habitat loss and pollutionIUCN.
The soringa whiting, also known simply as soringa or soringa sillago, is a poorly known species of coastal marine fish of the smelt-whiting family, Sillaginidae. The Soringa whiting is known exclusively from the east coast of India, inhabiting shallow inshore environments, particularly sandy substrates. S. soringa was first described in 1982 by Dutt and Sujatha, with the taxonomic status of the species was questioned by Roland McKay in his review of the Sillaginidae, with similar features to S. asiatica suggesting it is a senior synonym of the latter.
The estuarine whiting, also known as Vincent's whiting, is a species of benthic inshore marine fish of the smelt-whiting family, Sillaginidae. The estuarine whiting is very similar in appearance to the northern whiting, Sillago sihama, and as such was mistaken for the latter until 1980, when R.J. McKay identified the species based primarily on swimbladder morphology. The estuarine whiting is distributed along both the east and west coasts of India, primarily inhabiting the muddy substrates of estuaries. The species is locally important to fisheries in India, and is recognized as having aquaculture potential.
The stout whiting, also known as the yellow-cheek whiting or school whiting, is a species of benthic marine fish in the smelt-whiting family Sillaginidae. Like other sillaginids, it is an elongate, slightly compressed fish, growing to a maximum known length of 30 cm. The stout whiting is endemic to Australia, with the species divided into western and eastern populations, with the western population ranging from Shark Bay to Fremantle and the eastern population from Bustard Head, Queensland to northern New South Wales. The species inhabits deep, sandy continental shelf regions to a depth of at least 70 m.
The yellowfin whiting, also known as the western sand whiting or fine-scaled whiting, is a species of inshore marine fish in the smelt-whiting family Sillaginidae. The species is endemic to the eastern Indian Ocean, ranging from Dampier, Western Australia to Gulf St Vincent in South Australia, with an apparent division in the populations of the two states. Yellowfin whiting inhabit relatively shallow waters for their entire life, often found on tidal flats and creeks, as well as large estuaries. It is one of the largest members of the smelt-whiting family, growing to 42 cm, and can be distinguished by a number of anatomical and colour related features. Yellowfin whiting are benthic carnivores, preying predominantly on polychaete worms, with minor amounts of copepods, amphipods and bivalves also commonly taken. The species shows a change in diet with age, and also dietary differences with other sillaginids presumably to minimize competition. Reproduction occurs at different times throughout its range, generally focused around summer, with up to 217,000 eggs produced per season. Yellowfin whiting reach sexual maturity at around 20 cm, with each individual spawning more than once. The species forms the basis of major fisheries in both Shark Bay, Western Australia and the two Gulfs of South Australia, with around 260 tonnes of fish taken each year. They are also a popular target for shore based anglers, with a reputation as a very good table fish.
The Chinese sillago is a species of inshore marine fish in the smelt whiting family Sillaginidae, described in 2011. The species is known only to inhabit the coastal waters of China, primarily in estuarine tidal flats near Wenzhou, Zhejiang Province. The Chinese sillago was described in 2011 based on morphological and DNA barcode analysis of several specimens. Several detailed anatomic features distinguish it from other sillaginids, with Sillago parvisquamis its closest relative based on phylogenetic analysis. Nothing is known of the ecology or importance to fisheries of the Chinese sillago.