FAO Home>Fisheries & Aquaculture
FAO of the UN
Spisula solidissima:   (click for more)

See tree map  display tree map
  • Mactra solidissima  , (original description).
    FAO Names
    En - Atlantic surf clam, Fr - Mactre solide, Sp - Almeja blanca.
    3Alpha Code: CLB     Taxonomic Code: 3161202001
    Diagnostic Features
    Shell oval in shape, strong and smoothish, except for small, irregular growth lines. The lateral teeth bear very tiny, saw-tooth ridges. Chondrophore not set off by a plate. Ligament partially external.  Colour yellowish white with a thin yellowish brown periostracum. 
    Geographical Distribution
    Noth-eastern Atlantic: Spisula solidissima solidissima is distributed from the southern Gulf of St. Lawrence to Cape Hatteras. The subespecies Spisula solidissima similis (Say, 1822), the southern surfclam, is distributed to Cape Cod to both sides of Florida and to Texas.
    Habitat and Biology
    Common from shallow subtidal beach zones to depths of about 60 m; beyond 40 m its abundance is low.It is a common species in sandy bottoms, rarely occurring in muddy areas.Both oceanographic conditions involving hypoxia and trophic pressure have influence on their distribution and abundance. 
    Full sexual maturity in the second year of life (45-85 mm shell lenght) and spawining occurs usually in summer.  Rapid growth to about age 7; maximum age of 37 years (shell lenght 22.6 cm).It is an infaunal suspension-feeding bivalve,commonly preyed by sea stars, and gastropods.
    Up to 226 mm in lenght (usually between 100 to 190 mm).
    Interest to Fisheries
    Catched with hydraulic clam dredges. Spisula solidissima support an important commercial fishery in Atlantic North America. It is harvested commercially for over 40 years. The US surfclam fishery harvested in 1994 was 31.000 t of meats, with most of the catch taken from Mid-Atlantic waters between New Jersey and Virginia. Between 1950 and 1970, annual surfclam landings increased by 3.500 to 30.500 t declining by 50% between 1974 and 1976 due to overfishing. Since 1977, surfclam fisheries have been managed and a system of individual transferable quotas was adopted in 1991, a measure that stabilized the annual landings. The species has been considered for aquaculture in eastern Canada and USA. The total catch reported for this species to FAO for 1999 was 142 370 t. The countries with the largest catches were USA (142 067 t) and Canada (303 t).
    Local Names
    English : commercial surfclam ,  Atlantic surfclam ,  southern Atlantic surfclam (Spisula solidissima similis) .
    French : Mactre d'Amerique .
    The subspecies Spisula solidissima similis is more elongate, with its anterior slope flatter, and its pallial sinus longer and not sloping slightly upward. In the left valve, the tiny double tooth, just anterior to the spoon-shaped chondrophore, is usually much larger and stronger. It is moderately common and coexist with the typical species in the northern part of its range. It has a larger pallial sinus compared with Spisula polynyma .
    Abott, T.R. - 1954American shellfish. D. Van Nostrand Company, Inc. Princeton. 541 pp.
    Weinberg, J.R. - 1998Density-dependent growth in the Atlantic surfclam, Spisula solidissima, off the coast of the Delmarva Peninsula, USA Marine Biology. 130(4): 621-630.
    Weinberg, J.R., Murawski, S.A. & Serchuk, F.M. - 1997History and management of the U.S. Atlantic surfclam fishery. Journal of Shellfish Research 16(1): 277-278.
    Powered by FIGIS