The Pennsylvania Lucine
The Pennsylvania Lucine, Lucina pensylvanica (Linnaeus, 1758) is relatively common on the eastern coast of Florida, but no so common along the shores of the Southwest Florida. The shell of this member of the family Lucinidae may reach 2 inches in length. It is circular, with marked, irregularly distributed commarginal (“concentric”) growth lines and a strong posterior groove. The color is dirt-white, sometimes with hints of light brown imparted by the delicate periostracum. Its periostracum consists of fine extensions, each ending in a calcified (hard) “scale”. Well-preserved periostraca are, however, difficult to observe, as beach-collected valves are usually eroded. The illustration shows, on left, two views of a worn valve found in December 2014 by Susan Hewitt, on Sanibel (where the species is unusually rare). The additional illustration (on right), of a shell from the Bahamas collected by Colin Redfern, shows the scaly periostracum, characteristic of the species.
The Pennsylvania Lucine, Lucina pensylvanica. Shell on the right shows its delicate periostracum. Photos by José H. Leal.