Mercenaria species 

 Adult 



2 cm 



(from Goode 1884) 



Common Name: hard clam 

 Scientific Name: Mercenaria species 

 Other Common Names: Quahog, hard-shelled clam, 

 littleneck, cherrystone clam, chowder clam (Stanley 

 1985);pra/redusi7d(French),a/meyaGfe/sur(Spanish) 

 (Fischer 1978). Mercenaria mercenaria is known as 

 northern quahog, and M. campechiensis as southern 

 quahog (Turgeon et al. 1988). Andrews (1979) refers 

 to M. campechiensis as southern quahog, and subspe- 

 cies M. campechiensis texana as Texas quahog. 

 Classification (Turgeon et al. 1988) 

 Phylum: Mollusca 

 Class: Bivalvia 

 Order: Veneroida 

 Family: Veneridae 



Value 



Commercial : Although hard clams support a significant 

 commercial fishery in the United States as a whole, the 

 gulf coast of Florida supports only a very limited hard 

 clam fishery (Schroeder 1924, Taylor and Saloman 

 1 969). There was a substantial fishery in Florida's Ten 

 Thousand Islands until the 1930's, and clams were 

 taken to Key Westforcanning (Schroeder 1 924, Marelli 

 pers. comm.). During 1992, 27.7 metric tons (mt) of 

 hard clam meat valued at $64,000 was landed, on 

 Florida's Gulf coast (Newlin 1993). No landings are 

 reported for other Gulf coast states. The season for 

 clams harvested in Florida is regulated, and harvest is 

 restricted to approved shellfish areas (GSMFC 1993). 

 Dredges can be used for harvest on private leases after 

 posting a $3000 bond and securing a Special Activity 

 License. The minimum allowable harvest size for 

 clams is 7/8 inch (2.22 cm). In Texas, a commercial 

 mussel and clam fisherman's license is required to 

 commercially harvest hard clams (TPWD 1993). Har- 



vest is open year-round, but only from water approved 

 by the State Commissioner of Health. The traditional 

 and most popular method of harvesting hard clams has 

 been by rakes or tongs (Eversole 1987). In North 

 Carolina, they are harvested by "kicking" which uses 

 the wash from a boat propeller to dislodge clams from 

 the substrate. An otter trawl is towed behind the boat 

 to collect the clams. 



Recreational : Hard clams are sometimes taken for 

 home consumption by recreational fishermen. There 

 is a significant recreational fishery for hard clams in the 

 Tampa Bay area (Kunneke and Palik 1 984, Killam et al. 

 1992). The bag limit in Florida is two bushels per 

 person or boat (whichever is less) per day (GSMFC 

 1993, Arnold pers. comm). Harvesting is done mostly 

 by hand picking or treading. 



Indicator of Environmental Stress : Hard clams, like 

 other bivalves, are used to study the uptake and 

 bioaccumulation of heavy metals and toxic organic 

 chemicals (Boehm and Quinn 1977, Moore 1985, 

 Byrne 1989, Laughlin et al. 1989, Long et al. 1991). 

 Because of their filter feeding life mode and benthic 

 habitat, the presence of such compounds in clam 

 tissues can be indicative of poor water quality and 

 environmental stress (Eversole 1987). Evidence of 

 past geologic events can be traced through fossil shell 

 remains (Parker 1955, 1956). 



Ecological : Hard clams provide a food source to bot- 

 tom feeding fishes and invertebrates. Their larval 

 stages also provide food for larval and early juvenile 

 fishes. Through their suspension feeding activities 

 hard clams help to transfer phytoplankton primary 

 productivity to the higher trophic levels within the 



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