Shell Fouling and Behavior of the Caribbean Predatory Gastropod Cassis tuberosa

Abstract: The gastropod Cassis tuberosa (Linnaeus, 1758) usually lives in and on soft sediments and sea grass meadows. This carnivorous snail is primarily a semi-epifaunal and nocturnal hunter that, during daytime, rests burrowed in sediments. Around the Bahamian island of San Salvador, C. tuberosa has extended its behavior from nocturnal to metaturnal; feeding both night and day. This modification also involves further changes in behavior as an individual was observed resting epifaunally between rocks during the day even though this substrate was surrounded by soft bottoms. Epifaunal Cassis specimens are entirely encrusted primarily by coralline algae, but also by various green algae accompanied by vagile snails and crabs. The high degree of encrustation suggests that these snails do not remain burrowed for long periods of time. Cassis has thus extended its resting behavior from a semi-endofaunal to an epifaunal mode of life. The fouled shells also function as mobile benthic substrates for various organisms.