On feeding and behaviour of Ophiodromus flexuosus (Delle Chiaje) and Nereimyra punctata (O.F. Müller) (Polychaeta, Hesionidae)

Abstract

Food analyses and aquarium observations on Ophiodromus flexuosus and Nereimyra punctata from the Øresund, Denmark, and gut content analyses of O. flexuosus from Lindaspollene, west Norway, show that the species are carnivores and scavengers which search for food on the bottom. Small crustaceans and polychaetes are the most common prey; dead animals are utilized when encountered. The prey are swallowed whole. Most dissected specimens had food remains in the gut indicating frequent feeding during normal conditions. When prey are very abundant there is a high feeding activity.

In search of food O. flexuosus creeps slowly about on the sediment surface. Living prey are detected from the movements, apparently through the vibrations set up in the water. Orientation is klinotactic, and the worm sneaks insidiously up on the prey until it attacks with a violent protrusion of the pharynx. N. punctata constructs a burrow system where it waits for passing prey, but it also makes excursions to the sediment surface. The long cirri are spread out from the burrow opening, and prey location seems mainly dependent on tactile stimuli. Both species have strong chemical senses, but will attack a vibrating object without chemical stimuli.