Diet and feeding of the nassariid Buccinanops cochlidium from northern Patagonia, Argentina

Abstract

The Nassariidae are considered to be carrion feeders. Nevertheless, the feeding habits of this family also include herbivory, detritivory and carnivory. In the present study, we observed the diet and feeding behaviour of Buccinanops cochlidium from northern Patagonic waters. B. cochlidium fed mainly on living bivalves and, as an opportunistic carrion feeder, on diverse dead animals. It was commonly observed to feed in groups. When one individual of B. cochlidium caught a prey, other individuals approached and opportunistically fed on the remains. Juveniles fed exclusively on carrion, including prey recently killed by conspecific adult snails (39.5% of the scavenging events). Carrion represented 57.8% of the B. cochlidium diet on the whole. Predation seemed to be related to the size of B. cochlidium individuals, in particular, the foot, which is used to hold and manipulate the prey. We observed no feeding activity for gravid B. cochlidium females in the field. In summary, our results show that B. cochlidium is a carnivorous species, both as a scavenger and as a predator, that feeds mainly on dead crabs and living bivalves. Adults of B. cochlidium predated actively and fed opportunistically on dead animals of larger sizes, whereas hatchlings and juveniles fed exclusively on carrion, including by-products generated by the predation of larger B. cochlidium individuals.