Semicassis bisulcata is rarely seen in the Marshalls. Prior to 1999, we knew of only two empty shells found in the Marshalls, one each at Kwajalein and Enewetak Atolls. On a night dive off Kwajalein Island on 31 July of that year, we came across a cluster of three specimens on an egg mass in a patch of the seagrass Halophila. A fourth individual was about a half meter away, crawling toward the cluster. Although rare to us blundering humans, the mollusks seem to have no trouble finding each other. Unfortunately, we were able to get the living animals only on video, and the photo below is a rather poor frame capture of the scene. Since then, we never saw these again despite multiple night dives in the same area, and have seen no more specimens anywhere else in the Marshalls.
Created 10 January 2011
Updated 25 March 2020