FAO Home>Fisheries & Aquaculture
FAO of the UN
Ruditapes decussatus:   (click for more)

See tree map  display tree map
  • Cuneus reticulatus  da Costa, 1778; partim.
  • Venus fusca  Gmelin, 1791
  • Venus obscura  Gmelin, 1791
  • Venus variegata  Gmelin, 1791
  • Venus florida  Poli, 1795
  • Tapes decussatus var. quadrangula  Jeffreys, 1864: p. 360.
  • Venus vesta  Brusina, 1870: Brusina, 1870 ex Chiereghini ms.
  • Tapes extensus  Locard, 1886
    FAO Names
    En - Grooved carpet shell, Fr - Palourde croisée d'Europe, Sp - Almeja fina.
    3Alpha Code: CTG     Taxonomic Code: 3161102001
    Scientific Name with Original Description
    Venus decussata  Linnaeus, 1758. Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis. Edition 10, Tomus 1, Holmiae 824 pp.
    Diagnostic Features
    Shell broadly oval to quadrate, umbones distinctly anterior. Posterior hinge line straight, posterior margin truncate, anterior hinge line grading into the down-sloping anterior margin. Prominent posteriorly, where the shell is conspicuously decussate.  Sculpture of fine concentric striae and bolder radiating lines. Growth stages clear. Lunule and escutcheon poorly defined. Each valve with three cardinal teeth: centre one in left valve, and centre and posterior in right are bifid. Pallial line and adductor scars distinct. Pallial sinus U-shaped, not extending beyond mid-line of shell, but reaching a point below the posterior part of the ligament. Lower limb of sinus distinct from pallial line for the whole of its length.  Inner surfaces glossy white, often with yellow or orange tints, and with a bluish tinge along dorsal edge. Cream, yellowish, or light brown, often with darker markings. 
    Geographical Distribution
    From Southern and Western England to the Iberian Peninsula and into the Mediterranean. South to western Morocco and Senegal, West Africa. (Poppe & Goto, 1991).
    related Launch the Aquatic Species Distribution map viewer
    Habitat and Biology
    Lower shore and shallow subtidal.In sand, muddy gravel or clay, usually in quiet waters.Filter-feeding.
    In both sexes, ripe gametes were continually present on the coast of northwest Spain and continually released between April and August; spawning efficiency over this period was 60% in females and 83% in males. Again in both sexes, major spawning occurred in August/September (spawning efficiency 94% in females, 86% in males) (Rodriguez-Moscoso & Arnaiz, 1998). Gonadal development began in April for the carpet-shell clam in Ireland. First ripe specimens were observed in June and major spawning commenced in August. (Xie, Qiushi, Burnell, GM , 1994).  Growth parameters of the von Bertalanffy model estimated by Garcia (1993) are: K= 0.30, L¥ = 65,93, t0 = -0.09
    Up to 75 mm long.
    Interest to Fisheries
    This species is one of the most popular and profitable mollusc of lagoonal and coastal sites in the Mediterranean, where it was collected for a long time as food. But this kind of harvestind did not satisfy the market, and the culture of this species was started in some lagoon areas, mainly in Italy. However, as its farming was not completely successful, it was replaced in the early 1980's by a related Pacific species, T. philippinarum. FAO's Yearbook of Fishery Statistics reports a range of yearly production from around 2019 mt in 1995 to 1823 mt in 1999 (France, Ireland, Portugal, Spain, Tunisia). FAO's Yearbook of Fishery Statistics reports a range of yearly aquaculture production from around 7233 mt in 1995 to 4422 mt in 1999 (France, Portugal, Spain).
    It is consumed fresh and canned.
    Differing from T. philippinarum, this species shows little marked radial striae and siphons completely separated.
    Garcia, F. - 1993. Interprétation des stries valvaires pour l'évaluation de la croissance de Ruditapes decussatus L. Oceanologica Acta .  16: 199-203..
    Poppe, G. T. & Goto, Y. - 1991. European seashells. Vol 1 (Polyplacophora, Caudofoveata, Solenogastra, Gastropoda).Verlag Christa Hemmen . 
    Rodriguez-Moscoso, E & Arnaiz, R - 1998. Gametogenesis and energy storage in a population of the grooved carpet-shell clam, Tapes decussatus (Linne, 1787), in northwest Spain. Aquaculture. .  vol. 162, no. 1-2, pp. 125-139 ..
    Xie, Qiushi & Burnell, GM - 1994. A comparative study of the gametogenic cycles of the clams Tapes philippinarum (A. Adams & Reeve 1850) and Tapes decussatus (Linnaeus) on the south coast of Ireland. Journal of Shellfish Research. .  vol. 13, no. 2, pp. 467-472..
    Powered by FIGIS