White steenbras (Lithognathus lithognathus)

Description

White steenbras fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

White steenbras description

Often shimmering with a mother-of-pearl sheen, the white steenbras (Lithognathus lithognathus) is a silvery-grey fish, with a whiter underside ⁽³⁾. Seven dark vertical bars pattern each side of the rather elongated body ⁽³⁾, which are often darker in younger, smaller white steenbras ⁽²⁾. It has a long snout and a narrow mouth surrounded by thick lips, and the jaws bear tiny teeth ⁽³⁾.

Also known as

pignose grunter.

French

Marbré Du Cap.

Spanish

Erla, Herrera Del Cabo.

Size

Maximum length: 140 cm ⁽²⁾

Maximum weight: 30 kg ⁽²⁾

White steenbras biology

This often solitary fish has a remarkable manner of feeding. To obtain its diet of shrimps, worms, small crabs, periwinkles and other molluscs, the white steenbras blows a strong jet of water into the burrow in which the animal lives. This jet stream, created by the pumping action of the powerful gill covers forcing water through the narrow mouth, effectively blows the prey from its shelter ⁽³⁾. In extremely shallow water, the tail of the white steenbras is often seen poking through the water’s surface, as it works, snout down, to blast prey out of the sandy or muddy substrate ⁽³⁾.

Following a summer spent near the Western Cape, the white steenbras migrates to the eastern coasts of South Africa where it is known to spawn from June to August ^{(2) (3)}. After the fertilisation and hatching of the eggs, the resulting juveniles enter estuaries. Here they will remain, certainly for the first year of their life, sometimes staying for over two years ⁽²⁾. The white steenbras is sexually mature at about six years of age, and around 65 centimetres in length, at which time it moves from the surf zone areas of beaches into deeper coastal waters ⁽²⁾.

White steenbras range

The white steenbras occurs only in South Africa, where it is found from the Orange River to southern KwaZulu-Natal ⁽²⁾.

See this species on Google Earth.

White steenbras habitat

Small, juvenile white steenbras can be found in shallow water in estuaries, while larger juveniles typically occur in the surf zone areas of sandy beaches. Adult white steenbras are found in coastal waters down to a depth of 25 metres ⁽²⁾.

White steenbras status

The white steenbras is classified as Least Concern (LC) on the IUCN Red List ⁽¹⁾.

White steenbras threats

This popular food fish, and favourite of anglers, was once abundant around the coasts of South Africa, but numbers have now been severely reduced ^{(4) (5)}. Both over-fishing and habitat degradation are held responsible for the decrease in both commercial and recreational catches of this species off the Eastern Cape coast ^{(4) (5)}. The dependence of juvenile white steenbras on estuarine habitats makes them highly vulnerable to habitat degradation, as estuaries are typically greatly affected by the activities of humans, while the tendency of this species to aggregate when spawning makes it vulnerable to heavy fishing pressure ⁽⁴⁾.

White steenbras conservation

Measures are now in place to help ensure the future survival of this valuable South African species ⁽⁴⁾. The white steenbras is a protected species in South Africa ⁽³⁾, and severe fishing restrictions have been implemented ⁽⁴⁾, including a minimum catch size of 40 centimetres ⁽³⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For further information on sustainable seafood in Southern Africa:

• The Southern Africa Sustainable Seafood Initiative:
  http://www.wwfsassi.co.za/?m=1

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Glossary

Molluscs

A diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.

Spawning

The production or depositing of large quantities of eggs in water.

References

1. IUCN Red List (April, 2011)
   http://www.iucnredlist.org
2. South African Institute for Aquatic Biodiversity. (2004) Coastal Fishery Resources: An Easy Guide. SAIAB, Grahamstown, South Africa. Available at:
   http://www.saasta.ac.za
3. Van der Elst, R. (1993) A Guide to the Common Sea Fishes of Southern Africa. Struik Publishers, Cape Town.
4. Department of Environmental Affairs and Tourism, Republic of South Africa (September, 2008)
   http://soer.deat.gov.za/themes.aspx?m=431
5. Allanson, B.R. and Baird, D. (1999) Estuaries of South Africa. Cambridge University Press, Cambridge.