With 20 species and counting, the Venus clams family (Veneridae) is the most diverse (most species) of all the local, shallow-water bivalve families. There are species of many different sizes, ranging from the Brown Gem Clam (Parastarte triquetra) at 3 mm (about 0.12 inch) to the large Southern Quahog (Mercenaria campechiensis), which can exceed 150 mm (about 6 inches). Our featured species, the Gray Pigmy Venus, Chioneryx grus (Holmes, 1858), is one of the smallest (as its vernacular name implies), among the local Venus clams. The shell rarely exceeds 10 mm (about 0.4 inch) in length. It is elongate-rectangular, with a sculpture of radial ribs crossed by weaker concentric lines. The background shell color in the Gray Pigmy Venus is not always gray; it can also be whitish or light tan. Internally, the shell is white, with purple-brown posterior area, and often with a purplish hinge.
The Gray Pigmy Venus, from Sanibel. Photos by José H. Leal.