Observations on Extant Populations of the Softshell Clam, Mya arenaria Linné, 1758 (Bivalvia: Myidae), from Georgia (USA) Estuarine Habitats
The softshell clam, Mya arenaria Linné, 1758, is reported from Georgia (USA) estuarine habitats based on studies conducted between 1969 and 1972. Observations on Georgia estuarine habitats where extant populations of softshell clams occurred are described. On several occasions, fresh shells with periostracum and tissue remnants were found in a brackish drainage system on Sapelo Island. These shells represent the first southern records of extant populations of softshell clams from such a specialized habitat type. Living specimens of M. arenaria from the benthos and specimens in the stomach contents of stingrays (Dasyatis sabina) were collected at four stations during 1969 in the North and South Newport Rivers. mesohaline tidal systems forming part of the southern and northern headwaters of St. Catherines and Sapelo Sounds.The stomach of a stingray collected near the mouth of Little Ogeeche River during another study also contained specimens of M. arenaria. Ephemeral, intertidal, winter populations of juvenile softshell clams are reported from exposed Pleistocene beach faces along tidal rivers in Chatham, Georgia. The associated fauna collected with softshell clams and occurrence of other cold temperate and boreal species from Georgia estuaries are discussed. The distribution of M. arenaria appears to be mainly limited by a critical maximum temperature of 28º. The relatively cooler summer temperatures observed at the Sapelo Island tidal ditch site may enable the species to survive in this restricted habitat. Data from the present study indicate that during winter and spring, softshell clams appear to be bionomically important components of the benthos and the diet of stingrays in some Georgia estuarine habitats. Whether or not reproducing populations of M. arenaria occur year-round in Georgia estuaries still remains an open question.
Rasmussen, E. and R. W. Heard.
Observations on Extant Populations of the Softshell Clam, Mya arenaria Linné, 1758 (Bivalvia: Myidae), from Georgia (USA) Estuarine Habitats.
Gulf Research Reports
Retrieved from http://aquila.usm.edu/gcr/vol9/iss2/2