Biology:Polysteganus praeorbitalis
| Polysteganus praeorbitalis | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Spariformes |
| Family: | Sparidae |
| Genus: | Polysteganus |
| Species: | P. praeorbitalis
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| Binomial name | |
| Polysteganus praeorbitalis (Günther, 1859)
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| Synonyms | |
|
Dentex praeorbitalis Günther, 1859 | |
Polysteganus praeorbitalis, the Scotsman or Scotsman seabream, is a species of marine fish in the seabream family (Sparidae) of order Perciformes. It is native to Southern Africa.[2][3]
Description
Its body is oblong, robust, and slightly compressed, with one continuous dorsal fin. The caudal fin is slightly forked. It has a distinctive body shape, and is easily recognised. The forehead is steep, and the adult has a prominent hump on the nape. The deep body tapers towards the tail. Its eyes are small.
Adults are mostly reddish pink to pale blue-green, with numerous blue dots on the upper body and pearly scales below the lateral line. Usually, some silvery to blue lines occur around the eyes. Juveniles may be more yellowish and have three brown longitudinal stripes.[4]
The species attains at most 90 cm (35 in) in length, and weighs 11 kg (24 lb).[4] Its typical length is around 35.0 cm.[2]
Diagnostics
The dorsal fin has 12 spines, followed by 10 soft rays. The anal fin has eight rays. The pectoral fin is subequal to the head, and the ventral fin has one spine and five rays. The lateral line has 59 to 66 scales. Some 15 or 16 gill rakers occur on the lower limb of the first gill arch. The standard length is 2.5 to 2.8 times the body depth, and 3.0 to 3.2 times the head length.[4][3]
Distribution and habitat
Distribution is from Algoa Bay in the Eastern Cape, South Africa to Beira, Mozambique; it is Southern African endemic. It inhabits offshore reefs between 15 and 120 m in depth.[4] The maximum age recorded is 13 years, at a length of 72 cm, but it is believed to attain greater age based on size records.[1]
Diet
It feeds mainly on small reef fishes, but also on crustaceans and benthic cephalopods.[4][1]
Reproduction
The Scotsman matures around 40 cm in about 6 years, and aggregates for breeding and spawns off KwaZulu-Natal in winter, and possibly spring, mostly from Richard's Bay northwards. Normally solitary,[4] Polysteganus praeorbitalis is thought to be a protogynous hermaphrodite, but this is not yet confirmed.[1]
Importance to humans
For commercial and recreational line fishery, the catch restricted. Numbers have decreased considerably due to overfishing.[4][3][1]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Mann, B.Q.; Buxton, C.D.; Carpenter, K.E. (2014). "Polysteganus praeorbitalis". IUCN Red List of Threatened Species 2014: e.T170184A1288897. doi:10.2305/IUCN.UK.2014-3.RLTS.T170184A1288897.en.
- ↑ 2.0 2.1 Froese, Rainer and Pauly, Daniel, eds. (2016). "Polysteganus praeorbitalis" in FishBase. January 2016 version.
- ↑ 3.0 3.1 3.2 King, Dennis; Fraser, Valda (2014). The Reef Guide. Struik Nature. ISBN 978-1-77584-018-3.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Heemstra, P, and Heemstra, E., 2004. Coastal Fishes of Southern Africa, NISC/SAIAB, Grahamstown, ISBN:1-920033-01-7
Wikidata ☰ Q2393749 entry
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