Oliva panniculata is common in a couple of specific habitats at Kwajalein. Most often, they are found in fairly large pockets of sand on the top, more flat part of the seaward reef at depths of 3 to 10m. Occasionally, they are also found in similar sand pockets on the tops of large, flat-topped lagoon pinnacles. They are most often seen by sweeping the tops of wave-generated sand ripples. As this is an area that gets quite a bit of sand agitation from the waves, the small olives are extremely active and will start quickly digging back into the sand almost immediately upon being exposed. Maximum size is about 20mm.
Oliva panniculata is found in the same areas as another olive with about the same size and habits. When sweeping the sand ripples, about every tenth olive bears a pattern of wavy lines like that in the left shell below. For some time, we considered these to be color forms of the same species since they seemed identical except in shell color. The initial version of this web page showed them both as forms of O. panniculata. However, there appears to be no intergrading between the patterns. Perhaps more significantly, limited observation suggests they may behave differently. Oliva panniculata seems to be more active, digging back down into the sand when exposed more quickly then the wavey-lined olives. Experts in the field are currently treating this as a new species and work is underway to describe it.
This handful of olives was living in a small sand patch at about 7m depth.
Created 8 October 2010
Updated 29 November 2010