Estuarine whiting
Encyclopedia
The estuarine whiting, Sillago vincenti (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.
in the genus
Sillago
, which is one of three genera of the smelt whiting family
Sillaginidae
. The smelt-whitings are Perciformes
in the suborder Percoidea
.
The species was first scientifically described by Roland McKay of the Queensland Museum
in 1980, who was the first to recognize it as a distinct species from the anatomically similar S. sihama
. McKay designated a specimen collected in 1965 from Mandapam Camp
in India
to be the holotype
. It is commonly known as the estuarine whiting in reference to its preferred habitat, as well as Vincent's whiting in relation to its specific name. In India it is also referred to as 'Kalimeen'.
, with a dissection of the swimbladder required to identify the species in the field. The species is known to reach a maximum length of 30 cm.
The external morphology is similar to all sillaginids, having a fairly straight ventral profile and a slightly curved dorsal profile. The dorsal fin
is composed of two sections, the first consisting of 11 spines, while the second, longer dorsal has a single spine followed by 21 to 23 soft rays posteriorally. The anal fin has two spines and is followed by 22 or 24 soft rays. The scales
are ctenoid in nature except for the cheek scales, of which there are 2 rows of cycloid scales. There are 70 to 74 lateral line
scales and 34 vertebrae in total.
The anterior extremity of the swimbladder has a very short bulbous projection with 1 to 3 short anterolateral lobate or recurved extensions either side of the central projection. There is a single post coelomic extension and a duct like process on the ventral surface that continues to the vent.
The estuarine whiting's body and head are sandy to light olive above with a silvery side and a whitish belly. The head has a deeper golden tinge, as do parts of the silivery sides, which do not have a distinct lateral
silver band. The eye has a silver iris
and a golden outer surface, while the snout
has a dusky tinge. The opercle
is also dark yellow to golden. The spinous dorsal fin is hyaline
with the tips of the membranes dusky and blotched with fine dusted black spots. The second dorsal fin is hyaline to pale white with 5 to 7 rows of blackish spots, giving a vague appearance of lateral bands. The anal fin is also hyaline to milky white with white or yellow tips. The pectoral fin base is golden yellow, the ventral is white with a yellowish tip and the caudal fin is hyaline to dusky.
s of India
, with an apparent break in its range on the southern tip of India. This would suggest there are two separate population
s, but it is possible the fish has just not been identified correctly in this region. The species occurs in shallow inshore waters between 0 and 10 m deep, usually frequenting estuaries with mud
dy substrates. Estuarine whiting have also been known to form schools with northern whiting in these environments, adding to identification problems.
of the species is relatively unknown, with only two studies concentrated on estuarine whiting. In his description of S. vincenti, McKay noted that egg
bearing females of 25 to 28 cm in length were present in January and February, suggesting this to be at least part of the spawning
period. The second study was an investigation into the species diet, and was presented at the First Indian Fisheries Forum held in 1987. The publication of this meeting's proceedings is somewhat rare outside of India and thus can not be commented on at the present.
Estuarine whiting, along with other common sillaginids, are locally important to fisheries in India. Fishermen often catch the species in the upper reaches of estuaries, making it important in many communities situated in delta
ic regions of India. The species is recognized as having considerable potential for aquaculture
in impoundments and tidal ponds, with a reported rapid growth rate.
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 benthic inshore 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 estuarine whiting is very similar in appearance to the northern whiting
Northern whiting
The northern whiting, Sillago sihama , 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...
, 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
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...
, primarily inhabiting the muddy substrates
Substrate (marine biology)
Stream substrate is the material that rests at the bottom of a stream. There are several classification guides. One is:*Mud – silt and clay.*Sand – Particles between 0.06 and 2 mm in diameter.*Granule – Between 2 and 4 mm in diameter....
of estuaries. The species is locally important to fisheries in India, and is recognized as having aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
potential.
Taxonomy and naming
The estuarine 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 genera 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 scientifically described by Roland McKay of the Queensland Museum
Queensland Museum
The Queensland Museum is the state museum of Queensland. The museum currently operates four separate campuses; at South Brisbane, Ipswich, Toowoomba and Townsville.The museum is funded by the State Government of Queensland.-History:...
in 1980, who was the first to recognize it as a distinct species from the anatomically similar S. sihama
Northern whiting
The northern whiting, Sillago sihama , 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...
. McKay designated a specimen collected in 1965 from Mandapam Camp
Mandapam Camp
Mandapam camp was built in the early 1900s by the British Government to house migrant plantation workers coming to India from Sri Lanka. The Camp is located in South India, 700 km South of Chennai , the capital of the state of Tamil Nadu.In the late 1970s the Liberation Tigers of Tamil Eelam ...
in 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...
to be the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
. It is commonly known as the estuarine whiting in reference to its preferred habitat, as well as Vincent's whiting in relation to its specific name. In India it is also referred to as 'Kalimeen'.
Description
The estuarine whiting is very similar to S. sihama in its external morphologyMorphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, with a dissection of the swimbladder required to identify the species in the field. The species is known to reach a maximum length of 30 cm.
The external morphology is similar to all sillaginids, having a fairly straight ventral profile and a slightly curved dorsal profile. The 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...
is composed of two sections, the first consisting of 11 spines, while the second, longer dorsal has a single spine followed by 21 to 23 soft rays posteriorally. The anal fin has two spines and is followed by 22 or 24 soft rays. The scales
Scale (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...
are ctenoid in nature except for the cheek scales, of which there are 2 rows of cycloid scales. There are 70 to 74 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 34 vertebrae in total.
The anterior extremity of the swimbladder has a very short bulbous projection with 1 to 3 short anterolateral lobate or recurved extensions either side of the central projection. There is a single post coelomic extension and a duct like process on the ventral surface that continues to the vent.
The estuarine whiting's body and head are sandy to light olive above with a silvery side and a whitish belly. The head has a deeper golden tinge, as do parts of the silivery sides, which do not have a distinct lateral
Anatomical terms of location
Standard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
silver band. The eye has a silver iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
and a golden outer surface, while the snout
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
has a dusky tinge. 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....
is also dark yellow to golden. The spinous dorsal fin is hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
with the tips of the membranes dusky and blotched with fine dusted black spots. The second dorsal fin is hyaline to pale white with 5 to 7 rows of blackish spots, giving a vague appearance of lateral bands. The anal fin is also hyaline to milky white with white or yellow tips. The pectoral fin base is golden yellow, the ventral is white with a yellowish tip and the caudal fin is hyaline to dusky.
Distribution and habitat
The estuarine whiting is distributed on both the eastern and western coastCoast
A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...
s 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...
, with an apparent break in its range on the southern tip of India. This would suggest there are two separate 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, but it is possible the fish has just not been identified correctly in this region. The species occurs in shallow inshore waters between 0 and 10 m deep, usually frequenting estuaries with mud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
dy substrates. Estuarine whiting have also been known to form schools with northern whiting in these environments, adding to identification problems.
Biology and fishery
The biology and ecologyEcology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
of the species is relatively unknown, with only two studies concentrated on estuarine whiting. In his description of S. vincenti, McKay noted that egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
bearing females of 25 to 28 cm in length were present in January and February, suggesting this to be at least part of the spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
period. The second study was an investigation into the species diet, and was presented at the First Indian Fisheries Forum held in 1987. The publication of this meeting's proceedings is somewhat rare outside of India and thus can not be commented on at the present.
Estuarine whiting, along with other common sillaginids, are locally important to fisheries in India. Fishermen often catch the species in the upper reaches of estuaries, making it important in many communities situated in delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...
ic regions of India. The species is recognized as having considerable potential for aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
in impoundments and tidal ponds, with a reported rapid growth rate.