The silver sweep (''Scorpis lineolata''), also known as the false pompano, sweep, trumps or windawindawi, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

from the subfamily

Scorpidinae The Scorpidinae, commonly known as halfmoons, knifefishes, and sweeps, are a subfamily of the family Kyphosidae, the sea chubs, a family of marine fish in the order Perciformes. The Scorpidinae are distributed throughout the Pacific and east Ind ...

of the

sea chub The sea chubs, also known as rudderfish and pilot fish and in Hawaiian as ''enenue'' or ''nenue'', are a family, Kyphosidae, of fishes in the order Perciformes native to the Atlantic, Indian and Pacific Oceans usually close to shore in marine w ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Kyphosidae The sea chubs, also known as rudderfish and pilot fish and in Hawaiian as ''enenue'' or ''nenue'', are a family, Kyphosidae, of fishes in the order Perciformes native to the Atlantic, Indian and Pacific Oceans usually close to shore in marine w ...

. It is native to the southwestern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

from Australia to New Zealand.

Description

The silver sweep has deep and strongly compressed body with a thin caudal peduncle. The head is moderately sized with an almost straight dorsal profile, a short snout and quite large eyes. The mouth is small and oblique with small but strong teeth in the jaws arranged in broad bands with the outer band being enlarged and recurved. Most of the body is covered in very 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 ...

scales and there is a gently curved lateral line. The

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

continuous with a very short first spine, there are a 10 spines which progressively become higher towards the tail, the first rays in the soft-rayed portion of the dorsal fin is only slightly higher than the spiny portion giving the dorsal fin an almost straight profile. The soft-rayed part of the dorsal fin contains 26-28 soft rays. The anal fin has 3 spines and 27-28 soft rays. The soft portion of the dorsal fin is notably longer than they spiny portion. It has small

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

are small with the uppermost rays being the longest. The pelvic fins are also small and are located below and to the rear of the

s. Silver sweeps are greyish, blue-grey or green-grey dorsally and silver-grey ventrally, with the edge of the gill cover and the base of the pectoral fin being blackish. This species can reach a length of .

Distribution

The silver sweep is found in the southwestern Pacific Ocean off Australia and New Zealand. In Australia it is found from

Moreton Bay Moreton Bay is a bay located on the eastern coast of Australia from central Brisbane, Queensland. It is one of Queensland's most important coastal resources. The waters of Moreton Bay are a popular destination for recreational anglers and are ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

south to

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

and west as far as

Victor Harbor, South Australia Victor Harbor is a town in the Australian state of South Australia located within the City of Victor Harbor on the south coast of the Fleurieu Peninsula, about south of the state capital of Adelaide city centre, Adelaide. The town is the large ...

. It is also found in the

Tasman Sea The Tasman Sea ( Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer ...

around

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland P ...

and Norfolk Island. Silver sweep are a common fish on the east coast of Australia, particularly in New South Wales. In New Zealand silver sweep are distributed around the coast of the North Island.

Habitat and biology

Adult silver sweeps are found on coastal

reefs A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes—deposition of sand, wave erosion planing down rock out ...

at depths down to at least , It feeds on

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

over rock reefs where it forms schools while juveniles settle in

tide pools A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. Many of these pools exist as separate bodies of water only at low tide. Many tide pool habitats are home to especially adaptable animals that ...

and can be found in the

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estu ...

waters of

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 environmen ...

. They

spawn Spawn or spawning may refer to: * Spawn (biology), the eggs and sperm of aquatic animals Arts, entertainment, and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** '' Spawn: ...

in the winter with the peak breeding season between May and August. The eggs are pelagic. The young fish grow very quickly for the first 2–3 years but growth slows down significantly after sexual maturity, although they may live over 50 years. Silver sweeps have separate sexes.

Taxonomy

The silver sweep was first formally described by the

Austrian Austrian may refer to: * Austrians, someone from Austria or of Austrian descent ** Someone who is considered an Austrian citizen, see Austrian nationality law * Austrian German dialect * Something associated with the country Austria, for example: ...

ichthyologist

Rudolf Kner Rudolf Ignaz Kner (24 August 1810 – 27 October 1869) was an Austrian geologist, paleontologist, zoologist and ichthyologist. He also wrote some poems which were published by his brother-in-law K.A. Kaltenbrunner. Biography Kner was bo ...

in 1865 with the type locality given as Sydney in

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Fisheries

The silver sweep is of secondary importance as a target for commercial fisheries and is caught using

purse seine Seine fishing (or seine-haul fishing; ) is a method of fishing that employs a surrounding net, called a seine, that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. Seine nets can be de ...

s and trap nets. Since 1997-98 the amount landed in New South Wales has declined from nearly 15t to less than 50t. About 60t are caught annually in New South Wales by recreational fishermen. The flesh of the silver sweep is said to be firm and of excellent quality.

References

{{Taxonbar, from=Q2611007 Silver sweep Taxa named by Rudolf Kner Fish described in 1865