Scavenger gastropod devouring a common lamellibranch bivalve in an estuary of Northeast Brazil

Abstract

Nassaridae Iredale, 1916 (1835) is one of the main groups of scavenger neogastropods that usually live in a gregarious manner on soft and rocky substrates mainly of estuarine ecosystems in the seas and oceans of the World. The aim of this paper was to describe Phrontis polygonata (Lamarck, 1822) feeding on the carrion of the lamellibranch bivalve Anomalocardia flexuosa (Linnaeus, 1767) in an estuarine region of Northeast Brazil. A total of 27 adult individuals of P. polygonata were observed actively crawling on and around the venerid attempting to feed on its tissue. During the observation period, the proboscis of the nassarids could only reach the mantle margin of A. flexuosa due to the narrow spacing of the valves. This study reaffirms the ecological relevance of P. polygonata associated with the consumption of bivalve carrion in shallow estuarine waters of the Western Atlantic.