Population dynamics of the nonindigenous brown mussel Perna perna in the Gulf of Mexico compared to other world-wide populations

International shipping, particularly from South America, may have transported P. perna to the Gulf of Mexico (Hicks & Tunnell 1993), recent molecular genetic evidence suggesting origination from Venezuela populations (Holland 1997).The endemic range of P. perna (synonymous with P. picta [Born] and P. indica Kuriakose and Nair [Siddall 1980, Vakily 1989]) includes southern India, Sri Lanka, Madagascar, the east coast of Africa from central Mozambique to False Bay, and the African west coast from Luderiz Bay north into the Mediterranean from Gibraltar to the Gulf of Tunis, as well as the Atlantic coasts of Brazil, Uruguay, Venezuela, and the West Indies (Berry 1978).