Indian whiting
Encyclopedia
The Indian whiting, Sillago indica, 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 whiting inhabits the east and west coasts of the Indian subcontinent
, apparently not extending to the southern tip of India
. 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.
in the genus
Sillago
, which is one of three divisions of the smelt whiting family
Sillaginidae
. The smelt-whitings are Perciformes
in the suborder Percoidea
.
The species was first named by McKay in his comprehensive review of the Sillaginidae, with coauthors Dutt and Sujatha contributing the section on S. indica. The species was previously misidentified as Sillago parvisquamis by the latter two authors in earlier publications, with McKay pointing out the only noticeable difference between the two is the swim bladder morphology, as well as an indistinct black band in the side of the fish. For this reason, the fish goes unidentified in most catches, usually referred to as a number of other sillaginids. The species binomial and common name
reflects the species geographical distribution, confined to India
only.
extending to the cheek
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 is similar to the second dorsal fin, but has 2 spines with 22 to 23 soft rays posterior to the spines. Other distinguishing features include 68 to 70 lateral line
scales and a total of 34 vertebrae. The species has a known maximum length of 17 cm, and possibly longer.
The swim bladder is quite distinct, having a bifurcate anterior extensions, while the anterolateral extensions are recurved and extend to the ventral duct. There is a single posterior extension.
The colour of the Indian whiting is a light tan with a dark brown—blackish band starting behind the upper part of the opercle
and curving down below lateral line
for approximately two thirds the length and continuing slightly or directly on the lateral line as a broken band or elongate spots. The head, cheeks, belly
and lower sides are covered in a sprinkling of black spots. The interspinous membrane
of the first dorsal fin, the individual soft rays and the caudal fin are also spotted, with the caudal fin heavily spotted.
, with two population
s of the species known, with apparently no movement between these eastern and western populations. The species inhabits inshore coastal waters in a range of depths from 0 to 30 m. Due to its relatively recent naming and difficulty of identification, very little knowledge on the biology
of the species has been collected.
. It is often taken by drift net
, shore seine
and cast net by local fisheries, and by mini trawlers.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of coastal marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
of the smelt-whiting family Sillaginidae
Sillaginidae
The Sillaginidae, commonly known as the smelt-whitings, whitings, sillaginids, sand borers and sand-smelts, are a family of benthic coastal marine fishes in the order Perciformes. The smelt-whitings inhabit a wide region covering much of the Indo-Pacific, from the west coast of Africa east to Japan...
. The species was named in 1985, having previously being misidentified as another species of Sillago
Sillago
Sillago is one of three genera in the family Sillaginidae containing the smelt-whitings, and contains 29 species, making Sillago the only non-monotypic genus in the family. Distinguishing among Sillago species can be difficult, with many similar in appearance and colour, forcing the use of swim...
, S. parvisquamis. The Indian whiting inhabits the east and west coasts of the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
, apparently not extending to the southern tip of India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. 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.
Taxonomy and naming
The Indian whiting is one of 29 speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Sillago
Sillago
Sillago is one of three genera in the family Sillaginidae containing the smelt-whitings, and contains 29 species, making Sillago the only non-monotypic genus in the family. Distinguishing among Sillago species can be difficult, with many similar in appearance and colour, forcing the use of swim...
, which is one of three divisions of the smelt whiting family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Sillaginidae
Sillaginidae
The Sillaginidae, commonly known as the smelt-whitings, whitings, sillaginids, sand borers and sand-smelts, are a family of benthic coastal marine fishes in the order Perciformes. The smelt-whitings inhabit a wide region covering much of the Indo-Pacific, from the west coast of Africa east to Japan...
. The smelt-whitings are Perciformes
Perciformes
The Perciformes, also called the Percomorphi or Acanthopteri, is one of the largest orders of vertebrates, containing about 40% of all bony fish. Perciformes means perch-like. They belong to the class of ray-finned fish and comprise over 7,000 species found in almost all aquatic environments...
in the suborder Percoidea
Percoidea
Percoidea is a superfamily of fish of the order Perciformes....
.
The species was first named by McKay in his comprehensive review of the Sillaginidae, with coauthors Dutt and Sujatha contributing the section on S. indica. The species was previously misidentified as Sillago parvisquamis by the latter two authors in earlier publications, with McKay pointing out the only noticeable difference between the two is the swim bladder morphology, as well as an indistinct black band in the side of the fish. For this reason, the fish goes unidentified in most catches, usually referred to as a number of other sillaginids. The species binomial and common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
reflects the species geographical distribution, confined to India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
only.
Description
As with most of the genus Sillago, the Indian whiting has a slightly compressed, elongate body tapering toward the terminal mouth. The body is covered in small ctenoid scalesScale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
extending to the cheek
Cheek
Cheeks constitute the area of the face below the eyes and between the nose and the left or right ear. They may also be referred to as jowls. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve...
and head. The first dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
has 11 spines and the second dorsal fin has 1 leading spine with 21 to 22 soft rays posterior. The anal fin is similar to the second dorsal fin, but has 2 spines with 22 to 23 soft rays posterior to the spines. Other distinguishing features include 68 to 70 lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
scales and a total of 34 vertebrae. The species has a known maximum length of 17 cm, and possibly longer.
The swim bladder is quite distinct, having a bifurcate anterior extensions, while the anterolateral extensions are recurved and extend to the ventral duct. There is a single posterior extension.
The colour of the Indian whiting is a light tan with a dark brown—blackish band starting behind the upper part of the opercle
Operculum (fish)
The operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body....
and curving down below lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
for approximately two thirds the length and continuing slightly or directly on the lateral line as a broken band or elongate spots. The head, cheeks, belly
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
and lower sides are covered in a sprinkling of black spots. The interspinous membrane
Biological membrane
A biological membrane or biomembrane is an enclosing or separatingmembrane that acts as a selective barrier, within or around a cell. It consists of a lipid bilayer with embedded proteins that may constitute close to 50% of membrane content...
of the first dorsal fin, the individual soft rays and the caudal fin are also spotted, with the caudal fin heavily spotted.
Distribution and habitat
As suggested by its name, the Indian whiting is endemic to IndiaIndia
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, with two population
Population
A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
s of the species known, with apparently no movement between these eastern and western populations. The species inhabits inshore coastal waters in a range of depths from 0 to 30 m. Due to its relatively recent naming and difficulty of identification, very little knowledge on the biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
of the species has been collected.
Relationship to humans
Like all other species of Sillago, the Indian whiting is taken amongst inshore catches but not distinguished from other sillaginids, with no specific information available on the fisheryFishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
. It is often taken by drift net
Drift net
Drift netting is a fishing technique where nets, called drift nets, are allowed to float freely at the surface of a sea or lake. Usually a drift net is a gill net with floats attached to a rope along the top of the net, and weights attached to another rope along the foot of the net to keep the net...
, shore seine
Seine
The Seine is a -long river and an important commercial waterway within the Paris Basin in the north of France. It rises at Saint-Seine near Dijon in northeastern France in the Langres plateau, flowing through Paris and into the English Channel at Le Havre . It is navigable by ocean-going vessels...
and cast net by local fisheries, and by mini trawlers.