Sweeper
Encyclopedia
Sweepers are small, tropical marine (occasionally brackish) perciform fish
of the family
Pempheridae. Found in the western Atlantic Ocean
and Indo-Pacific
region, the family contains approximately 26 species
in two genera
. One species (Pempheris xanthoptera ) is the target of subsistence fisheries
in Japan
, where the fish is much enjoyed for its taste. Sweepers are occasionally kept in the marine aquarium
.
; both cycloid and ctenoid scale
s may be present. The small, short dorsal fin
begins before the body's midpoint and may have 4-7 spines; the anal fin is extensive and usually has 3 spines. The mouth is subterminal and strongly oblique. Species of the genus Parapriacanthus have much more cylindrical bodies.
Some species possess photophore
s. All but the curved sweeper (Pempheris poeyi) possess a gas bladder
. The largest species is the common bullseye (Pempheris multiradiata) at 28 centimetres in length; most other species measure 16 centimetres or less. Coloration is relatively subdued.
Characteristically shallow water, schooling fish (especially as juveniles), sweepers are nocturnal and seek shelter under ledges or in the caves, nooks and crannies of reef
s or eroded, rocky shorelines during the day. They are often found sharing these hiding places with cardinalfishes and bigeyes, fellow nightowls. At night, sweepers forage for zooplankton
, their primary food items.
At least one species, the small-scale bullseye (Pempheris compressa) of Australia
, is known to enter coastal estuaries
whilst young.
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 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...
Pempheridae. Found in the western Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and Indo-Pacific
Indo-Pacific
The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
region, the family contains approximately 26 species
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...
in two genera
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...
. One species (Pempheris xanthoptera ) is the target of subsistence 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,...
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...
, where the fish is much enjoyed for its taste. Sweepers are occasionally kept in the marine aquarium
Marine aquarium
A marine aquarium is an aquarium that keeps marine plants and animals in a contained environment. Marine aquaria are further subdivided by hobbyists into fish only , fish only with live rock , and reef aquaria. Fish only tanks often showcase large or aggressive marine fish species and generally...
.
Physical description
Deeply keeled, compressed bodies and large eyes typify sweepers, their form somewhat like hatchetfishHatchetfish
The name hatchetfish may refer to two unrelated groups of fishes:*Marine hatchetfishes, small deep-sea bioluminescent fishes of the family Sternoptychidae, subfamily Sternoptychinae....
; both cycloid and ctenoid scale
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...
s may be present. The small, short 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...
begins before the body's midpoint and may have 4-7 spines; the anal fin is extensive and usually has 3 spines. The mouth is subterminal and strongly oblique. Species of the genus Parapriacanthus have much more cylindrical bodies.
Some species possess photophore
Photophore
A photophore is a light-emitting organ which appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors...
s. All but the curved sweeper (Pempheris poeyi) possess a gas bladder
Gas bladder
The swim bladder, gas bladder, fish maw or air bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming...
. The largest species is the common bullseye (Pempheris multiradiata) at 28 centimetres in length; most other species measure 16 centimetres or less. Coloration is relatively subdued.
Behaviour
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s or eroded, rocky shorelines during the day. They are often found sharing these hiding places with cardinalfishes and bigeyes, fellow nightowls. At night, sweepers forage for zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
, their primary food items.
At least one species, the small-scale bullseye (Pempheris compressa) of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, is known to enter coastal estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
whilst young.
Species
There are 26 species in two genera:- Genus Parapriacanthus
- Parapriacanthus dispar (Herre, 1935).
- Slender bullseye, Parapriacanthus elongatus (McCulloch, 1911).
- Parapriacanthus marei Fourmanoir, 1971.
- Pigmy sweeper, Parapriacanthus ransonneti SteindachnerFranz SteindachnerFranz Steindachner was an Austrian zoologist.- Work and career :Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess...
, 1870.
- Genus Pempheris
- New Zealand bigeyeNew Zealand bigeyeNew Zealand bigeye, Pempheris adspersa, is a sweeper of the genus Pempheris, found around New Zealand to depths of about 100 metres, in reef areas of broken rock containing suitable caves and overhangs...
, Pempheris adspersa Griffin, 1927. - Dusky sweeper, Pempheris adusta BleekerPieter BleekerPieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....
, 1877. - Black-tipped bullseye, Pempheris affinis McCulloch, 1911.
- Bronze sweeper, Pempheris analis Waite, 1910.
- Small-scale bullseye, Pempheris compressa (White, 1790).
- Pempheris japonica Döderlein, 1883.
- Klunzinger's bullseye, Pempheris klunzingeri McCulloch, 1911.
- Black-edged sweeper, Pempheris mangula CuvierGeorges CuvierGeorges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
, 1829. - Pempheris molucca CuvierGeorges CuvierGeorges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
, 1829. - Common bullseye, Pempheris multiradiata Klunzinger, 1880.
- Pempheris nyctereutes JordanDavid Starr JordanDavid Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
& Evermann, 1902. - Pempheris ornata Mooi & Jubb, 1996.
- Pempheris otaitensis CuvierGeorges CuvierGeorges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
, 1831. - Silver sweeper, Pempheris oualensis CuvierGeorges CuvierGeorges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
, 1831. - Curved sweeper, Pempheris poeyi Bean, 1885.
- Pempheris rapa Mooi, 1998.
- Glassy sweeper, Pempheris schomburgkii Müller & Troschel, 1848.
- Pempheris schreineri Miranda-Ribeiro, 1915.
- Black-stripe sweeper, Pempheris schwenkii BleekerPieter BleekerPieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....
, 1855. - Vanikoro sweeper, Pempheris vanicolensis CuvierGeorges CuvierGeorges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
, 1831. - Pempheris xanthoptera Tominaga, 1963.
- Pempheris ypsilychnus Mooi & Jubb, 1996.
- New Zealand bigeye