Annular Seabream ( Diplodus annularis )

/ / Fish

Description

Diplodus annularis is a medium sized fish, 10-15cm in length, with a maximum length of 24cm (1) (2). There are 8 incisiform front teeth and molariform teeth are present (1).

The dorsal fin of D. annularis has 11 spines and 11-13 soft rays; the anal fin has just 3 spines and 11-12 soft rays, the caudal fin is forked (2). There are 48-56 lateral line scales up to the caudal base (1).

Annular Sea Bream has a silvery white colour and an almost annular dark band is found around the caudal peduncle, behind the dorsal and anal fin (2). The pelvics are yellow, the others fins are lighter and dark spots are found at the upper pectoral axil. Juveniles will only be found with only 5 narrow, dark crossbars.

There are approximately 11 other species of Diplodus, with only 4 others being found in the Mediterranean Sea. None of the species have been evaluated by the IUCN redlist for a conservation status (3).

Behaviour

D. annularis are gregarious when young, living in large schools (1) (2); once mature, smaller groups are formed. It is benthopelagic, and like other sparids is often found frequenting the surf zone, primarily at dawn (4).

Habitat

The Annular sea bream is found in the littoral zone, mostly in Zostera seagrass beds (5), but also on Posidonia beds and sandy bottoms, in depths of 0-90m (2) (6). Juveniles will enter brackish waters and lagoons at the end of winter (2).

Live Cycle

The spawning season of D. annularis is in the winter (1), the egg and larvae are planktonic. Sexual maturity is reach after one year; these fish are potential hermaphrodites and certain individuals are protandric (6).

Distribution

D. annularis is found in the Eastern Atlantic from the Bay of Biscay to Gibraltor, Madeira and the Canary Islands. It is also found in the Mediterranean, Black Sea and Sea of Azov (1) (2) (6).

Food

The Annular Sea Bream is a carnivore; it mainly feeds on molluscs, but will also be found ingesting worms, crustaceans, echinoderms and hydrozoans (1) (2).

Conservation Status

Not evaluated under the IUCN Redlist (3).

References

Description written by Ben Harvey (2009)

(1) Golani, D., Özturk, B. and Başusta, N. 2006. Fishes of the Eastern Mediterranean. Turkish Marine Research Foundation, Istanbul, Turkey. 259pp.

(2) Linnaeus, C. 1758. Systema Naturae, ed. X, vol. 1, 824 pp. Nantes & Pisces: pp. 230-338. (Reprint, 1956, London.)

(3) IUCN 2009. IUCN Red List of Threatened Species. Version 2009.1. <www.iucnredlist.org>. Downloaded on 27 July 2009.

(4) Sala, E. & Ballesteros, E., 1997. Partitioning of space and food resources by three fish genus Diplodus (Sparidae) in a Mediterranean rocky infralittoral ecosystem. Marine Ecology Progress Series, (152), pp.273-83.

(5) Bauchot, M.L. and Hureau, J.C. 1990. Sparidae. In Check-list of the fishes of the eastern tropical Atlantic (CLOFETA). Paris: UNESCO.

(6) Bauchot, M.L. and Hureau, J.C., 1986. Sparidae. In Fishes of the north-eastern Atlantic and the Mediterranean. Paris: UNESCO.