Mytella charruana (d'Orbigny, 1846) Charrua Mussels In Duval Co., Florida

Mytella charruana (d'Orbigny, 1846) Charrua Mussels

    This exotic species, native to South America, was first identified in Duval County during 1986 when it was found clogging the filters at the Jacksonville Electric Authority's (JEA) Northside Generating Station which draws water from the St. Johns River (report and discussion) but had disappeared by 1987. According to Dr. Patrick Baker (University of Florida/IFAS), his students collected the species from a floating dock at Mayport near the mouth of the St. Johns River in Duval County (2006). However, several follow-up visits to that location by this reporter during 2007 failed to find any evidence of Mytella. The next confirmed sighting of the mussel in the county took place during January of 2007 when a single live specimen was collected from intertidal substrate (a wooden pole) at Mayport Naval Station beach. The species was then next discovered in large numbers attached to floating docks at two different locations well up the St. Johns River in the Arlington section of Jacksonville (12/2007 and 2/2008). Not surprisingly, on 8/28/2008 the JEA once again reported problems with their facilities cooling water system due to the presence of mussels. The specimens provided by JEA were confirmed as Mytella charruana.

    Mytella charruana has also been found on a floating pier at the University of Florida's Whitney Laboratory at Marineland in northern Flagler County, Florida (October, 2006) and on a settlement plate in the Guana Tolomato Matanzas National Estuarine Research Reserve in St. Johns County, Florida (August, 2012). Additionally, the species has been found in the Mosquito Lagoon in Volusia County, Florida, the St. Marys River at St. Marys, Camden County, Georgia and the estuary of the Canoochee River, Liberty-Bryan Counties, Georgia.

The map above depicts the locations where the Charrua Mussel has thus far been found living in Duval County, Florida.



Date Found

Jacksonville Electric Authority Northside Generating Station (St. Johns River) [site image] 10/20/1986

Intertidal wooden poles at Mayport Naval Station (Atlantic Ocean) [site image] 1/22/2007

Lonnie Wurn boat ramp floating dock (4131 Ferber Road) (St. Johns River) [site image] 12/5/2007

Arlington Lions Club boat ramp and floating docks (St. Johns River)  [site image] 2/2/2008


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