Mass mortality of C. maximum in Moorea, French Polynesia

During our July 2015 surveys in Moorea, French Polynesia, we observed a massive mortality event of our focal study organism, Cereasignum (previously Dendropoma) maximum.

Vermetid nets from Hal
Typical situation with healthy vermetids extruding nets over surface of coral. Photo courtesy of Hal Lescinsky.
Situation in the midst of the die-off. Snails had stopped secreting mucus nets, had lost mass, and were deeply retracted into their tubes. Over a two week period, 90% of the snails were dead (typically mortality rates are approximately 10% per year).