AMMODYTIDAE
sand-eels

  Gymnammodytes semisquamatus
(Jourdain, 1879)

Relevant synonyms
None

Misidentification
None

Meristic formula
D, 53-56; A, 26-31; P, 12-15*

* Note: meristic counts in the Mediterranean are lower than those reported in the northeastern Atlantic.

 drawing : Tuvia Kurz    

SHORT DESCRIPTION
Body elongated and subcylindrical, with myotomes clearly visible. Ventrolateral skin fold, extending from the base of the pectoral fin to just beyond the rear end of this fin. Lower jaw protruding beyond upper jaw; teeth absent. Dorsal and anal fins elongated, their margins undulated. Pelvic fin absent. Body naked, except posterior third where some small cycloid scales are present but inconspicuous. Lateral line branched, with pores at ends of branches. Swim bladder absent.

color : silvery, with the back dark brown and the flanks and belly whitish. In some specimens, a pale brownish pigmentation appears on the flacks.

size : common (in the Mediterranean) 7-14 cm (max. 28 cm).

DISTINGUISHING CHARACTERISTICS

  • Gymnammodytes cicerelus: the ventrolateral skin fold extends from the base of the pectoral fin to beyond the anal fin. Iridescent silvery coloration, with the back bluish-grey and the flanks and belly whitish. In this species it is possible to observe a strip of quite marked dark pigmentation along the top part of the flanks and over the head.
    Other Ammodytidae species: lateral line unbranched.

    BIOLOGY / ECOLOGY
    Feeds on zooplankton. Eggs demersal and adhesive, attaching to sand-grains. Larva are pelagic and appear from April to June.

    habitat : sandy gravel bottoms between 5 and 20 m depth, with dial movements by feeding actively in the water mass during the daytime. Schooling behavior well developed.


  • 1st MEDITERRANEAN RECORD
    Off northeastern Iberian coast, 1990.


    DISTRIBUTION
    Worldwide : Eastern North Atlantic, from the southern coast of Norway to Spain. Mediterranean : recorded first off northeastern Iberian coast (Sabatés et al., 1990).

    ESTABLISHMENT SUCCESS
    Seems more and more frequent along the Spanish coast; but may be often confused by fishermen with Gymnammodytes cicerelus.

    speculated reasons for success :
    -


    MODE OF INTRODUCTION
    Via Gibraltar.


    IMPORTANCE TO HUMANS
    Used for bait and food in some areas. In the Catalan coast, the two Gymnammodytes species are exploited in a seasonal commercial fishery using modified boat seine nets.


    KEY REFERENCES

    • Reay P.J., 1986. Ammodytidae. In: Whitehead P.J.P., Bauchot M.L., Hureau J.C., Nielsen J. and Tortonese E. (eds.). Fishes of the north-eastern Atlantic and the Mediterranean. Vol. 2. pp. 945-950, UNESCO, Paris.
    • Sabatés A., Demestre M. and Sánchez P., 1990. Revision of the family Ammodytidae (Perciformes) in the Mediterranean with the first record of Gymmnammodytes semisquamatus. Journal of the Marine Biological Association of the United Kingdom, 70: 493-504.

    FEEDBACK / COMMENTS TO AUTHORS



    Last update of the species sheet:
    April 2002

    ©ciesm 2002