PROSOBRANCHIA - Predation of Cowries

These four cowry shells from Hastings Point were all dead collected and show evidence of attacks by
predatory molluscs. I have collected many cowries with these holes in the base, always on the inner lip
and towards the posterior or spire where access can be gained to the softer internal organs. Drill holes
on the dorsal area near the spire are rare. Also I have never seen a hole on the outer lip as the cowry
is able to pull away from an attack in this area so it is evident that the attacker is intelligent enough
to know the best point of entry.

Octopus spp are known to be able to "drill" holes in the shells of prey to inject a poison, weakening
the animal, which can then be removed. Some gastropod snails such as Muricids and Naticids are also
able to drill into shelled prey to feed. Having only ever found the empty shells I am unable to say for
certain what animal is responsible.