KYtVrence: Bwl Bui!., 150: 57-68. (February, 1976) OBSERVATIONS ON THE FOOD AND FEEDING BEHAVIOR OF ESTUARINE NEMERTEAN WORMS BELONGING TO THE ORDER HOPLONEMERTEA 1 JOHN J. McDERMOTT Department of Biology, Franklin and Marshall College, Lancaster, Pennsylvania 17604 The majority of nemerteans are carnivores or scavengers, but the exact nature of the food and the feeding habits of most species is poorly documented. Certain species belonging to two classes, Anopla and Enopla, capture and ingest whole animals from many of the invertebrate phyla (Hyman, 1951 ; Gibson, 1972). Under laboratory conditions, some nemerteans may be maintained on homogenized liver, starch paste, and cooked beef fat (Gibson, o/>. cit.}. In the laboratory they also may be cannibalistic or may feed on other nemertean species. Hoplonemerteans (Enopla), all of which have armed proboscides, in some cases strike a prey species with the proboscis and immobilize it with an injected toxin. As is the case in the larger heteronemerteans (Anopla), the prey is then either ingested whole (Roe, 1970 J or, by other hoplonemerteans which feed on arthropods, sucked out of the exoskeleton (Hickman, 1963 ; Jennings and Gibson, 1969). Some hoplonemerteans are known to consume a variety of prey species, but some are such specialists that they may starve in the laboratory if not provided with the correct prey (Jennings and Gibson, 1969; Roe, 1970). The purpose of this paper is to present laboratory observations on the capture and ingestion of live prey by three species of estuarine hoplonemerteans of the sub-order Monostylifera. Their food, food preferences and feeding behavior will be compared with findings from similar studies on other monostyliferans, thus develop-ing a more comprehensive understanding of feeding within the group, and defining more precisely the niches of these worms. MATERIALS AND METHODS The three species studied were Tctrastcinma. elegans (Girard, 1852), Zygo-iicincrtcs rircsccns (Verrill, 1879), and Amphiporus ochraccns (Verrill, 1873). They were identified according to the criteria described by McCaul ( 1963) . All were collected during the summers of 1971, 1973 and 1974 from beds of eelgrass (Zostcra marina L.) located at Gloucester Point, Virginia, where the salinity of the water was approximately 2Q f / f o. Marsh (1973) found both Tetra-stcinina and Zygo-ncmcrtes in equal abundance in his study of the epifauna of eelgrass near Gloucester Point, but I found Tctrastcinma to be far more common. Amphiporus, though not a rare species on eelgrass, is much less common than the other two (Marsh, 1973; Orth, 1971). Specimens of Zygonemertes were obtained also from among hydroids and bryozoans on wooden pilings at \Yachapreague, Virginia, where the salinity was 1 Contribution No. 724, from the Virginia Institute of Marine Science, Gloucester Point, Virginia. 57
BioStor
