Small-scale whiting
Encyclopedia
The small-scale whiting, Sillago parvisquamis (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 crustacean
s, molluscs and annelid
s. 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 pollution, but has not been recognised as such by the IUCN.
Sillago
, which contain 29 other species. It is part of the Sillaginidae
family which is a division of the Percoidei
, a suborder of the Perciformes
.
The species was first scientifically described by Theodore Gill
in 1861 in the first review of the sillaginid fishes; "Synopsis of the Sillaginoids". The type specimen was taken from the waters of Kanagawa, near Yokohama
in Japan
. There has only been one formal misidentification, made by Peter Forsskål
in 1913 when he mistook the species for Sillago sihama. The name "small-scale whiting" is in reference to the species' smaller than average scales amongst the genus Sillago.
is in two parts, the first made of feeble spines and the second of soft rays headed by a single feeble spine. The first dorsal fin has either 12 or 13 dorsal spines, a feature unique among Sillago which otherwise have 11 dorsal spines. The second dorsal fin has a single spine followed by 20 to 22 soft rays, while the anal fin has 2 spines and 22 or 24 soft rays. Other distinguishing features include 79 to 84 lateral line
scales and 39 to 40 vertebrae, while the swimbladder morphology also is a highly distinguishing feature. The maximum known size of the species is 30 cm.
The swimbladder has two anterior extensions that arise medially, diverge and terminate. Two lateral extensions appear anteriorally, each with a blind tubule
which curves to the abdominal walls and becomes a complex network of blind tubules. There are two posterior tapering extensions that project into and terminate into the caudal region. A duct like process is present from the lateral surface to the urogenital opening. This configuration is very similar to S. sihama, except that the lateral tubules are more complex than in S. sihama.
The small-scale whiting is a pale brown to dull brown colour above and lighter below with a faint mid-lateral band normally present. The fins are all hyaline
in appearance except for the dorsal fin which becomes dusky terminally with 5 or 6 rows of dusky spots on the soft dorsal fin membrane.
consisting of southern Japan
, Taiwan
, Korea
and India
. In Japan the species is known from the southern half of the island chain below Tokyo
in the west and Yokohama
in the east. The species is rare in both Korea and India, with only a single reported capture of the species in these countries. The species inhabits waters from 0 to 30 m in depth, often found on well developed tidal flats in the estuaries of large rivers. The larva
e and juveniles of the species commonly inhabit these environments also, with juveniles often inhabiting the shallowest parts of the tidal flats.
s, molluscs and annelid
worms. Studies in the Buzen Sea of Japan have found the small-scale whiting spawn
s from May to July, while laboratory studies have similarly found that spawning occurs from May to September with a peak from June to July.
Laboratory conditions also showed that spawning occurs at night predominantly between 20:30 and 22:00 hours. The eggs
are buoyant and spherical in shape with an average diameter
of 0.71 mm and are transparent and colourless. Larval and juvenile development has been extensively described by Imoto and Matsui (2000), with a number of characteristics including higher numbers of myomere
s and melanophores on the dorsal surface of the body as well as a lack of a vertical band of melanophores on the caudal peduncle distinguishing the larvae from those of S. japonica
. Modelling based on growth observations in the species suggests the female starts life smaller than the male but grows faster and is larger than the male within two years. The models put forward by Imoto et al. in 1997 also suggest that the male reaches a maximum of 288 mm while the female reaches 332 mm, assuming their life span
is long enough for these theoretical maxima to be reached.
n region, S. parvisquamis is commonly taken in seines from beach
es and estuaries but often suffers the same fate of other lesser known sillaginids in being confused with S. sihama. This identification issue, as well as the fact that fisheries statistics
are poor or non-existent in such countries means catch statistics are not available. In a 1984 review of the Japanese sillaginids, Sano and Mochizuchi described the species as being endangered due to habitat destruction
and pollution
, a statement echoed in a number of other papers since, although the IUCN does not recognise the species as being in danger. The discovery of the species in Korea in 1996 suggests its range may be greater than previously supposed, and thus less in danger of extinction
than proposed by Sano and Mochizuchi. The flesh is held in high regard in Japan, but is still considered inferior to that of S. japonica. For this reason, McKay proposed in 1992 that the species is possibly a candidate for aquaculture
, although such a move has not yet been made.
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 small-scale whiting is very similar in body shape and colour to other species in the genus 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...
, but is distinguished by having 12 or 13 spines in 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...
compared to 11 in all other species. The species is distributed through parts of the west Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
including Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
and 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...
, inhabiting the tidal flats of major estuaries. It is a benthic predator taking crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, molluscs and annelid
Annelid
The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...
s. 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...
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
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...
. Minor fisheries exist for the small-scale whiting, although it is thought be endangered by habitat loss and pollution, but has not been recognised as such by the IUCN.
Taxonomy and naming
The small-scale whiting is a member of the genusGenus
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 contain 29 other species. It is part of 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...
family which is a division of the Percoidei
Percoidei
Percoidei is one of eighteen suborders of bony fish in the order Perciformes. Many commercially harvested fish species are contained in this suborder, including the snappers, jacks, whitings, groupers, bass, perches and porgies.-Divisions:...
, a suborder of the 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...
.
The species was first scientifically described by Theodore Gill
Theodore Gill
Theodore Nicholas Gill was an American ichthyologist, mammalogist, malacologist and librarian.Born and educated in New York City under private tutors, Gill early showed interest in natural history. He was associated with J...
in 1861 in the first review of the sillaginid fishes; "Synopsis of the Sillaginoids". The type specimen was taken from the waters of Kanagawa, near Yokohama
Yokohama
is the capital city of Kanagawa Prefecture and the second largest city in Japan by population after Tokyo and most populous municipality of Japan. It lies on Tokyo Bay, south of Tokyo, in the Kantō region of the main island of Honshu...
in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. There has only been one formal misidentification, made by Peter Forsskål
Peter Forsskål
Peter Forsskål, sometimes spelled Pehr Forsskål, Peter Forskaol, Petrus Forskål or Pehr Forsskåhl, was a Swedish explorer, orientalist, naturalist and an apostle of Carl Linnaeus.-Early life:...
in 1913 when he mistook the species for Sillago sihama. The name "small-scale whiting" is in reference to the species' smaller than average scales amongst the genus Sillago.
Description
The small-scale whiting is very similar in external appearance to many other members of the genus Sillago, which have a slightly compressed, elongate body tapering toward the terminal mouth. The dorsal finDorsal 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 in two parts, the first made of feeble spines and the second of soft rays headed by a single feeble spine. The first dorsal fin has either 12 or 13 dorsal spines, a feature unique among Sillago which otherwise have 11 dorsal spines. The second dorsal fin has a single spine followed by 20 to 22 soft rays, while the anal fin has 2 spines and 22 or 24 soft rays. Other distinguishing features include 79 to 84 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 39 to 40 vertebrae, while the swimbladder morphology also is a highly distinguishing feature. The maximum known size of the species is 30 cm.
The swimbladder has two anterior extensions that arise medially, diverge and terminate. Two lateral extensions appear anteriorally, each with a blind tubule
Tubule
A tubule is a very small tube or fistular structure.A system of surface-connected membranes in muscle that enables a nerve impulse to travel to the interior of the muscle fibre.In anatomy, a tubule is a minute tube lined with glandular epithelium....
which curves to the abdominal walls and becomes a complex network of blind tubules. There are two posterior tapering extensions that project into and terminate into the caudal region. A duct like process is present from the lateral surface to the urogenital opening. This configuration is very similar to S. sihama, except that the lateral tubules are more complex than in S. sihama.
The small-scale whiting is a pale brown to dull brown colour above and lighter below with a faint mid-lateral band normally present. The fins are all 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...
in appearance except for the dorsal fin which becomes dusky terminally with 5 or 6 rows of dusky spots on the soft dorsal fin membrane.
Distribution and habitat
The small-scale whiting occupies a fairly restricted range in the northwest Pacific OceanPacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
consisting of southern Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
and 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...
. In Japan the species is known from the southern half of the island chain below Tokyo
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
in the west and Yokohama
Yokohama
is the capital city of Kanagawa Prefecture and the second largest city in Japan by population after Tokyo and most populous municipality of Japan. It lies on Tokyo Bay, south of Tokyo, in the Kantō region of the main island of Honshu...
in the east. The species is rare in both Korea and India, with only a single reported capture of the species in these countries. The species inhabits waters from 0 to 30 m in depth, often found on well developed tidal flats in the estuaries of large rivers. The larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e and juveniles of the species commonly inhabit these environments also, with juveniles often inhabiting the shallowest parts of the tidal flats.
Biology
Like other sillaginids, S. parvisquamis is a benthic predator and is known to consume a variety of crustaceanCrustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, molluscs and annelid
Annelid
The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...
worms. Studies in the Buzen Sea of Japan have found the small-scale whiting spawn
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...
s from May to July, while laboratory studies have similarly found that spawning occurs from May to September with a peak from June to July.
Laboratory conditions also showed that spawning occurs at night predominantly between 20:30 and 22:00 hours. The eggs
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...
are buoyant and spherical in shape with an average diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
of 0.71 mm and are transparent and colourless. Larval and juvenile development has been extensively described by Imoto and Matsui (2000), with a number of characteristics including higher numbers of myomere
Myomere
Myomere are the blocks of skeletal muscle tissue found commonly in chordates. They are commonly zig-zag, "W" or "V"-shaped muscle fibers. The myomeres are separated from adjacent myomere by connective tissues and most easily seen in larval fishes or in the olm...
s and melanophores on the dorsal surface of the body as well as a lack of a vertical band of melanophores on the caudal peduncle distinguishing the larvae from those of S. japonica
Japanese whiting
The Japanese whiting, Sillago japonica, is a common species of coastal marine fish belonging to the smelt-whiting family, Sillaginidae...
. Modelling based on growth observations in the species suggests the female starts life smaller than the male but grows faster and is larger than the male within two years. The models put forward by Imoto et al. in 1997 also suggest that the male reaches a maximum of 288 mm while the female reaches 332 mm, assuming their life span
Life expectancy
Life expectancy is the expected number of years of life remaining at a given age. It is denoted by ex, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience...
is long enough for these theoretical maxima to be reached.
Relationship to humans
Like many species of Sillago in the AsiaAsia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
n region, S. parvisquamis is commonly taken in seines from beach
Beach
A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...
es and estuaries but often suffers the same fate of other lesser known sillaginids in being confused with S. sihama. This identification issue, as well as the fact that fisheries statistics
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
are poor or non-existent in such countries means catch statistics are not available. In a 1984 review of the Japanese sillaginids, Sano and Mochizuchi described the species as being endangered due to habitat destruction
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
and pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
, a statement echoed in a number of other papers since, although the IUCN does not recognise the species as being in danger. The discovery of the species in Korea in 1996 suggests its range may be greater than previously supposed, and thus less in danger of extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
than proposed by Sano and Mochizuchi. The flesh is held in high regard in Japan, but is still considered inferior to that of S. japonica. For this reason, McKay proposed in 1992 that the species is possibly a candidate 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...
, although such a move has not yet been made.