Echinolittorina tuberculata (common pricklywinkle snails) on phytokarst (San Salvador Island, Bahamas) 1 (15382863043)

Description:

Description: Echinolittorina tuberculata (Menke, 1828) - common pricklywinkle snails on phytokarst. These common pricklywinkle snails are on a phytokarst surface of aragonitic calcarenite limestones of the Hanna Bay Member (upper Rice Bay Formation, middle to upper Holocene). They are supratidal rocky shore bacteria/algae grazers. Notice that the coloration and shell ornament well camouflages them against the mottled dark gray to light gray, irregular limestone surfaces. The jagged, pitted rock surface is phytokarst, formed by limestone being subjected to slow, partial dissolution by the life activities of bacteria and algae that coat the surfaces (= dark gray films). The snails are feeding on these biofilms by using their radulas to scrape away at the substrate. Phytokarst is one type of epikarst - limestone dissolution features at the top of the vadose zone. Classification: Animalia, Mollusca, Gastropoda, Littorinidae Locality: rocky cliffs along southern shoreline of Graham’s Harbour, just west of Bahamas Field Station, northern margin of San Salvador Island, eastern Bahamas. Date: 19 June 2010, 07:31. Source: Echinolittorina tuberculata (common pricklywinkle snails) on phytokarst (San Salvador Island, Bahamas) 1. Author: James St. John.