The Intermediate whiting (''Sillago intermedia''), is a species of

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

al marine

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

of the smelt-whiting

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Sillaginidae The Sillaginidae, commonly known as the smelt-whitings, whitings, sillaginids, sand borers and sand-smelts, are a family (biology), family of benthic coastal Marine (ocean), marine fish historically classified in the order (biology), order Percif ...

. The intermediate whiting ranges from the west coast of

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

to the

Gulf of Thailand The Gulf of Thailand (), historically known as the Gulf of Siam (), is a shallow inlet adjacent to the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. ...

in the east, inhabiting

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

y substrates in shallow waters. First identified in 1977 from a

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository f ...

found in a fish

market Market is a term used to describe concepts such as: *Market (economics), system in which parties engage in transactions according to supply and demand *Market economy *Marketplace, a physical marketplace or public market *Marketing, the act of sat ...

, the species has had little research performed on its

biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...

, and is frequently misidentified as '' Sillago sihama'' or '' Sillago maculata'' intermediate whiting are commonly caught by

fishermen A fisherman or fisher is someone who captures fish and other animals from a body of water, or gathers shellfish. Worldwide, there are about 38 million commercial and subsistence fishers and fish farmers. Fishermen may be professional or recr ...

throughout their range and are marketed fresh locally.

Taxonomy and naming

The intermediate whiting is one of over 30 species in the genus ''

Sillago ''Sillago'' is a genus of fish in the family (biology), family Sillaginidae and the only non-monotypic genus in the family. Distinguishing the species can be difficult, with many similar in appearance and colour, forcing the use of swim bladder ...

'', which is one of five genera belonging to the smelt whiting family

, this family was previously considered to be part of the

Percoidea Percomorpha () is an extremely large and diverse clade of ray-finned fish. With more than 17,000 known species (including tuna, seahorses, gobies, cichlids, flatfish, wrasse, perches, anglerfish, and pufferfish) known from both marine and fresh ...

, a

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

of the

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

. The 5th edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' classifies the Sillaginidae in the order

Spariformes Spariformes is an order of ray-finned fishes consisting of six families within the series Percomorpha. Taxonomy Spariformes was first used as a taxonomic term in 1860 by the Dutch physician, herpetologist and ichthyologist Pieter Bleeker. Trad ...

. The species was first recognized and named ''Sillago intermedius'' by Wongratana in 1977 after a number of unknown sillaginid individuals were found in a Thai fish market whilst Wongratana was collecting specimens of sillaginids to be sent to McKay for his review of the Sillaginidae. He based his description on a

taken from the east coast of Thailand in 1977, which was allocated to be the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

. The species has been subsequently misidentified as ''Sillago maculata'', as the blotches on the species are fairly similar.

Description

As with most of the genus ''Sillago'', the intermediate whiting has a slightly compressed, elongate body tapering toward the terminal mouth. The body is covered in small

ctenoid A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

extending to the two rows of

cheek The cheeks () constitute the area of the face below the eyes and between the nose and the left or right ear. ''Buccal'' means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the inside of th ...

scales and head. The first

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

has 11 spines and the second dorsal fin has 1 leading spine with 21 to 22 soft rays posterior. The

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

is similar to the second dorsal fin, but has 2 spines with 21 to 22 soft rays posterior to the spines. Other distinguishing features include 67 to 70

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

scales and a total of 34

vertebrae Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

. The species has a known maximum length of 20 cm. The

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

has two anterior extensions which extend forward and diverge before terminating above the auditory capsule. Two lateral extensions commence

anteriorly Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Thi ...

, sending tubules to the anterior and extending below the abdominal wall adjacent to the swimbladder. There are also two posterior extensions which project into the post-coelomic region. The morphology of the swim-bladder is quite similar to ''S. sihama'', but the tubules are very simple, unlike ''S. sihama'' which has complexly folded extensions. The intermediate whiting is a pale silvery

colour Color (or colour in Commonwealth English; see spelling differences) is the visual perception based on the electromagnetic spectrum. Though color is not an inherent property of matter, color perception is related to an object's light absorp ...

, being darker on top and lighter below. The top of the snout is blackish, while the

opercle The operculum is a series of bones found in bony fish and chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contains four bon ...

, preopercle and preorbital are bright silver. The sides of the body below the lateral line have a longitudinal row of 8 or 9 dark blotches. The back also has a row of dusky blotches. The

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

has darker upper and lower rays, with all other fins

hyaline A hyaline substance is one with a glassy appearance. The word is derived from , and . Histopathology Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellula ...

in appearance.

Distribution and habitat

As its name suggests, the intermediate whiting occurs predominantly in

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

where it ranges the Gulf of Thailand, extending westward to the west coast of the

Indian subcontinent The Indian subcontinent is a physiographic region of Asia below the Himalayas which projects into the Indian Ocean between the Bay of Bengal to the east and the Arabian Sea to the west. It is now divided between Bangladesh, India, and Pakista ...

, apparently having a fairly scattered distribution. The intermediate whiting is a shallow water,

inshore A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

species which inhabits open

y substrates at depths of 0 to 10 m, occasionally entering

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

. Nothing else known of its biology.

Relationship to humans

Like other sillaginids, the intermediate whiting is taken on a small scale by

throughout its range, where it is sold fresh in local

markets Market is a term used to describe concepts such as: *Market (economics), system in which parties engage in transactions according to supply and demand *Market economy *Marketplace, a physical marketplace or public market *Marketing, the act of sat ...

. It is often not differentiated form other sillaginids due to its close resemblance to both ''S. sihama'' and ''S. maculata''.

References

External links

Thai whiting at Fishbase
{{Taxonbar, from=Q2303228 Intermediate whiting Taxa named by Thosaporn Wongratana Fish described in 1977