Jarbua terapon (Terapon jarbua)

A boldly patterned, small fish, the jarbua terapon (Terapon jarbua) is characterised by the curved, dark brown bands that run along the length of its body, which provide excellent camouflage on the sandy sea bed where shadows are cast by ripples on the water’s surface ⁽³⁾. Silver-grey on the upperside and silver-white on the underside, with an iridescent sheen on the head, body and fins ^{(2) (3)}, the jarbua terapon may also be identified by the blotches of black on the first, deeply-notched dorsal fin and the tail fin, which has black-tipped and black-barred lobes ^{(3) (4) (5)}. Like other members of the grunter family of fish (Terapontidae), the jarbua terapon has a rather compressed, oblong body with a strong, powerful spine on each gill cover, and a slightly downward-pointing mouth armed with numerous small, sharp teeth ⁽⁴⁾.

Also known as

crescent bass, crescent grunter, crescent perch, crescent-banded grunter, crescent-banded tiger-fish, jarbua, target fish, thornfish, tiger bass, tigerfish, tiger-perch.

Synonyms

Coius trivittatus, Holocentrus servus, Pterapon trivittatus, Sciaena jarbua, Stereolepis inoko, Terapon timorensis, Therapon farna.

Size

Maximum length: 36 cm ⁽²⁾

An omnivorous predator, the jarbua terapon has a varied diet of fish, algae and invertebrates, which are all taken near the sea bed ⁽²⁾. It also displays another, slightly more unusual feeding strategy by consuming the scales of other live fish. It does this by initially settling in a slight depression in the sand and waiting for an unsuspecting victim to swim past. It then vigorously sweeps its tail so as to create a dense cloud of sand and thereby prevent its prey from spotting it as chunks of scales are taken from the prey’s body ⁽⁴⁾. This stealthy predator, however, may also fall prey to other fish, but when captured it often assumes a characteristic U-shaped posture, with the body bent almost double, by contracting the muscles along one side of the body. This makes the fins and spines around the gills erect so that the jarbua terapon becomes very difficult to swallow and is subsequently released by its captor ⁽⁵⁾. The jarbua terapon spawns in the sea, which takes place in spring off the South African coast ⁽⁴⁾. 

Wide-ranging across the Indian and Pacific Oceans, the jarbua terapon is distributed from the Red Sea and east African coast through Southeast Asia to the Samoan Islands, southern Japan and Australia. It also occurs around a number of oceanic islands, including the Seychelles, Maldives and Mauritius ^{(2) (3) (6)}.

The jarbua terapon is primarily a coastal species found in tropical and warm temperate brackish waters over shallow sand bottoms, often in the vicinity of river mouths. It also occurs in mangroves and may even enter freshwater. Juvenile jarbua terapons commonly use sandy intertidal areas as nurseries and are often found in tidal pools ^{(2) (3) (4) (7)}.

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

While the current extent of the threats to the jarbua terapon is currently unclear, it is captured in fisheries across its range. In many places it is considered unpalatable and is mainly caught as bycatch in fisheries targeting other species, with up to five tonnes of grunters landed by New South Wales fisheries alone each year ⁽⁸⁾. In the Far East, however, this species is captured as a food fish ^{(2) (4)}.

The jarbua terapon has not been the target of any known conservation measures.

Environment Agency - Abu Dhabi is a principal sponsor of ARKive. EAD is working to protect and conserve the environment as well as promoting sustainable development in the Emirate of Abu Dhabi.

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

For more information on fish conservation, see:

• World Fisheries Trust:
  http://www.worldfish.org/

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Algae

Simple plants that lack roots, stems and leaves but contain the green pigment chlorophyll. Most occur in marine and freshwater habitats.

Brackish

Slightly salty water, usually a mixture of salt and freshwater, such as that found in estuaries.

Bycatch

In the fishing industry, the part of the catch made up of non-target species.

Dorsal fin

The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.

Intertidal

Pertaining to the intertidal zone, the region between the high tide mark and low tide mark.

Invertebrates

Animals with no backbone, such as insects, worms, spiders and corals.

Omnivorous

Feeding on both plants and animals.

Spawning

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

1. IUCN Red List (June, 2011)
   http://www.iucnredlist.org/
2. FishBase – Jarbua terapon (November, 2010)
   http://www.fishbase.org/Summary/SpeciesSummary.php?ID=4458
3. Randall, J.E. (1994) Coastal Fishes of Oman. University of Hawaii Press, Honolulu.
4. Van der Elst, R. (1993) A Guide to the Common Sea Fishes of Southern Africa. Struik Publishers, Cape Town.
5. Heemstra, P. and Heemstra, E. (2004) Coastal Fishes of Southern Africa. NISC, South Africa.
6. Pauly, D. and Martosubroto, P. (1996) Baseline Studies of Biodiversity: The Fish Resources of Western Indonesia. ICLARM, Philippines.
7. Australian Museum – Jarbua terapon (November, 2010)
   http://australianmuseum.net.au/Crescent-Grunter-Terapon-jarbua
8. New South Wales Government – Jarbua terapon (November, 2010)
   http://www.dpi.nsw.gov.au/research/areas/systems-research/wild-fisheries/outputs/2008/972/status_short/Striped-Grunters.pdf