OBSERVATIONS ON FEEDING IN A SOUTH-AFRICAN SUCTORIAL HOPLONEMERTEAN, NIPPONNEMERTES SP. (FAMILY CRATENEMERTIDAE)

Marine hoplonemerteans were collected intertidally in Algoa Bay, Port Elizabeth, South Africa in 1983. Living worms appear to belong to the genus Nipponnemertes, perhaps N. africanus (Wheeler, 1940). The extern al morphology and the stylet apparatus are described and illustrated. Laboratory observations showed that this species attacked and consumed two species of sympatric amphipods, Elasmopus pecrenicrus and Hyale g randicornis (the only two species tested). The feeding behavior was si milar to that documented for other suctorial nemerteans that feed on a mphipods. One complete feeding sequence, from the initial strike to co mpletion of feeding on H. grandicornis, took approximately 12 min: the proboscis struck the ventral side of the amphipod, which was immobili zed in <1 min; the head eventually wedged between the sternal plates, and the internal organs were evacuated by suctorial action. The additi on of E. pectenicrus and H. grandicornis as potential prey for suctori al hoplonemerteans brings the total known number of amphipod species t o 25, involving at least ten families. A summary of all species of Amp hipoda known to be potential prey for suctorial hoplonemerteans is pre sented.