Freshwater Mussels of Florida

Genus Lampsilis

Accounts for Genera and Species 252 Genus Lampsilis Rafinesque 1820 Turgeon et al. (1998) recognized 28 Lampsilis species and 4 subspecies. Subsequently , four species—Lampsilis altilis, Lampsilis australis, Lampsilis perovalis, and Lampsilis subangulata—were moved to Hamiota when that genus was described (Roe and Hartfield 2005). Lampsilis haddletoni was moved to Obovaria by Williams et al. (2008). Lampsilis floridensis has been variously treated as a subspecies or synonym of Lampsilis teres until recognized as a valid species by Williams et al. (2008). Lampsilis straminea claibornensis was determined to be indistinguishable from Lampsilis straminea straminea and was placed in synonymy of that species by Williams et al. (2008). This leaves Lampsilis with a total of 24 recognized species and 3 subspecies. Lampsilis is wide ranging, occurring from Hudson Bay, Great Lakes, and Mississippi basins east to Atlantic Coast basins from Nova Scotia to Georgia. On the Gulf Coast it occurs in basins from the Rio Grande east to Tampa Bay in peninsular Florida. There are three species of Lampsilis in Florida. type Species Unio ovatus Say 1817 = Lampsilis ovata (Say 1817) Diagnosis Shell moderately thin to thick; smooth; outline oval to elliptical; sexual dimorphism distinct, females inflated posterioventrally; umbo sculpture undulating or weakly double -looped ridges; periostracum shiny, dull in a few species; pseudocardinal and lateral teeth thin to moderately thick, 2 in left valve, 1 in right valve. Females usually with well-developed mantle flap just ventral to incurrent aperture (Figure 10.52), usually rudimentary in males. Inner lamellae of inner gills mostly or completely connected to visceral mass, may have small opening at posterior end; outer gills marsupial; glochidia held in posterior portion of gill; marsupium extended beyond original gill margin when gravid, ventral margin often pigmented; glochidium outline subspatulate, without styliform hooks (Simpson 1900a; Ortmann 1912; Kraemer 1970). Figure 10.52. Female Lampsilis ornata mantle flap display—side view (left) and top view (right). Photographs by Paul L. Freeman and Paul D. Johnson. 253 Genus Lampsilis Lampsilis floridensis (Lea 1852) Florida Sandshell Lampsilis floridensis – First image: female, length 97 mm, UF 20437. Conecuh River, Gantt Reservoir [Lake], Covington County, Alabama, 1961. © Richard T. Bryant. Second image: female, length 80 mm, UF 4989. Mosquito Creek, 1 mile south of Chattahoochee, Gadsden County, Florida, October 1953. © Richard T. Bryant. Third image: male, length 86 mm, UF 4989. Mosquito Creek, 1 mile south of Chattahoochee, Gadsden County, Florida, October 1953. © Richard T. Bryant. Fourth image: male, length 71 mm, UF 65736. Escambia River near Flomaton, Escambia County, Alabama, May 1917. © Richard T. Bryant. Description Size: length to 131 mm, in Florida to 120 mm. Shell: moderately thin; smooth; moderately compressed, width 20%–35% of length; outline elliptical; anterior margin rounded; posterior margin narrowly rounded to bluntly pointed in females, narrowly rounded in males; dorsal margin straight to slightly convex; ventral margin straight to convex; posterior ridge rounded; posterior slope flat to slightly Accounts for Genera and Species 254 convex; umbo broad, elevated slightly above hinge line; umbo sculpture moderately thick, undulating ridges, somewhat nodulous where they cross posterior ridge, with slight indentation just anterior to posterior ridge; umbo cavity wide, shallow. teeth: pseudocardinal teeth moderately small, triangular, occasionally compressed, 2 teeth in left valve, anterior tooth larger, crest oriented anterioventrally, aligned through center of anterior adductor muscle scar, 1 tooth in right valve, occasionally with accessory denticle anteriorly; lateral teeth moderately long, thin, straight to slightly curved, 2 in left valve, 1 in right valve; interdentum moderately long, narrow. Nacre: white, usually highly iridescent. Periostracum: shiny, occasionally dull; dark yellow, usually rayless or with few green rays on posterior slope in Escambia, Choctawhatchee, Apalachicola, and Ochlockonee River basins, light yellow, with green rays on posterior portion of shell in Suwannee, Withlacoochee (southern), and Hillsborough River basins. Glochidium Description Outline subspatulate; length 180–210 µm; height 213–262 µm; width 120 µm; ventral margin with internal irregularly perpendicular rows of spatulate micropoints (Figure 10.53). The unusual spatulate micropoints were also observed in Lampsilis teres by Hoggarth (1999). Similar Sympatric Species Lampsilis floridensis superficially resembles Lampsilis straminea but is more elongate and males are more pointed posteriorly. Lampsilis floridensis may resemble some individuals of Hamiota subangulata but is more elongate and usually has fewer green rays. Distribution in Florida Lampsilis floridensis occurs in most major Gulf Coast basins from Escambia River to Hillsborough River (Figure 10.54). ecology and Biology Lampsilis floridensis inhabits medium creeks, rivers, lakes, and floodplain sloughs...