Small-eyed whiting
Encyclopedia
The small-eyed whiting, Sillago microps, is a poorly known species
of coast
al marine
fish
of the smelt-whiting family
Sillaginidae
. The species is known from only two specimen
s; 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
.
Sillago
, which is one of three divisions of the smelt whiting family Sillaginidae
. The smelt-whitings are Perciformes
in the suborder Percoidei
.
The species was first described by Roland McKay in his 1985 review of the Sillaginidae based on two specimens collected from a Taipei
market, Taiwan
; one of which was designated to be the type specimen. The species binomial and common name
s both reflect the distinguishing feature of the species; its unusually small eyes.
, with the only obvious distinguishing feature of the species being its unusually small eye size (only 14% to 16% of head length), as well as its swim bladder morphology
. Other diagnostic features include the spine and ray counts, with the first spinous dorsal fin
having 11 spines and the second dorsal fin having one spine and 19 soft rays. The anal fin has two spines followed by 19 soft rays. The species has 34 vertebrae and 68 to 69 lateral line
scales, with cycloid cheek scales. The species reaches at least 20 cm in length.
The body is a pale to dull brown colour, lighter on the underside of the fish and usually having a faint mid-lateral band below the lateral line. The fins are all hyaline
in colour with the exception of the spinous dorsal fin which is dusky at the tips, with five or six rows of dusky spots on the membranes of the second dorsal fin.
, Taiwan
. No other records of the fish have been reported. The habitat of the species is also largely unknown, but the only specimens were taken alongside both Sillago sihama and Sillago parvisquamis which inhabit primarily sandy and silty substrates in major estuaries, thus indicating S. microps may as well.
Nothing else is known of the biology or the contribution to local fisheries of the small-eyed whiting.
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 coast
Coast
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...
al marine
Marine biology
Marine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather...
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
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 species is known from only two specimen
Specimen
A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...
s; 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...
collected by Roland McKay in 1985 from a Taipei
Taipei
Taipei City is the capital of the Republic of China and the central city of the largest metropolitan area of Taiwan. Situated at the northern tip of the island, Taipei is located on the Tamsui River, and is about 25 km southwest of Keelung, its port on the Pacific Ocean...
market, both specimens of which were taken from the waters of 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...
. 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
Fishery
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,...
.
Taxonomy and naming
The small-eyed whiting is one of 29 species in 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 is one of three divisions 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 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 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:...
.
The species was first described by Roland McKay in his 1985 review of the Sillaginidae based on two specimens collected from a Taipei
Taipei
Taipei City is the capital of the Republic of China and the central city of the largest metropolitan area of Taiwan. Situated at the northern tip of the island, Taipei is located on the Tamsui River, and is about 25 km southwest of Keelung, its port on the Pacific Ocean...
market, 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...
; one of which was designated to be the type specimen. 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...
s both reflect the distinguishing feature of the species; its unusually small eyes.
Description
The small-eyed whiting is very similar in appearance to other members of the genus SillagoSillago
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...
, with the only obvious distinguishing feature of the species being its unusually small eye size (only 14% to 16% of head length), as well as its swim bladder morphology
Morphology (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....
. Other diagnostic features include the spine and ray counts, with the first spinous 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...
having 11 spines and the second dorsal fin having one spine and 19 soft rays. The anal fin has two spines followed by 19 soft rays. The species has 34 vertebrae and 68 to 69 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, with cycloid cheek scales. The species reaches at least 20 cm in length.
The body is a pale to dull brown colour, lighter on the underside of the fish and usually having a faint mid-lateral band below the lateral line. 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 colour with the exception of the spinous dorsal fin which is dusky at the tips, with five or six rows of dusky spots on the membranes of the second dorsal fin.
Distribution and habitat
The only two recorded specimens of the small-eyed whiting were taken from a market in TaipeiTaipei
Taipei City is the capital of the Republic of China and the central city of the largest metropolitan area of Taiwan. Situated at the northern tip of the island, Taipei is located on the Tamsui River, and is about 25 km southwest of Keelung, its port on the Pacific Ocean...
, 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...
. No other records of the fish have been reported. The habitat of the species is also largely unknown, but the only specimens were taken alongside both Sillago sihama and Sillago parvisquamis which inhabit primarily sandy and silty substrates in major estuaries, thus indicating S. microps may as well.
Nothing else is known of the biology or the contribution to local fisheries of the small-eyed whiting.