FEAR THE CRAWLING DEAD: CASSID PREDATION ON CLYPEASTEROID ECHINOIDS
Numerous individuals of the Caribbean clypeasteroids Leodia sexiesperforata and Clypeaster rosaceus were collected and analyzed in 2015 and 2017. The drill holes feature several characteristics typical for acidic etching such as exposing the skeleton’s stereom that still can protrude into the hole’s lumen, a concave drill hole wall as well as a distinctive drill hole shape. The comparison between drilling frequencies in different years indicate that the clypeasteroid Leodia sexiesperforata underlies high predatory stress with drilling frequencies up to 100%, thus representing a major food source for the cassid gastropod. The much scarcer Clypeaster rosaceus also shows a drilling frequency of around 90%. A comparison along the two echinoid taxa indicate that cassids prefer the oral side of the test for drilling.