LIFE-CYCLE OF CURTUTERIA-AUSTRALIS N-SP (DIGENEA, ECHINOSTOMATIDAE, HIMASTHLINAE), INTESTINAL PARASITE OF THE SOUTH ISLAND PIED OYSTERCATCHER

Curtuteria australis is described from the small intestine of the South Island pied oyster- catcher, Haematopus ostralegus finschi. It differs from its three congeners in having 31 collar spines and unbranched excretory arms, and in the extent of vitellaria. The final host and the primary and intermediate hosts were all collected at the Heathcote-Avon estuary, near Christchurch, New Zealand. The primary host is the whelk Cominella glandiformis, the digestive gland of which is invaded by rediae. These give rise to free-swimming cercariae which emerge at water temperatures above 20°c. Cercariae are sucked into the mantle cavity of the cockle Chione stutchburyi, the intermediate host, through the inhalant siphon, and encyst in the muscles of the anterior end of the foot. Metacercariae were fed to day-old domestic chickens, and adult C. australis were retrieved after 5 days. Prevalence in the whelk was 3.2%, in the cockle 63.6%, and in the oystercatcher 50.4%. As in most littoral habitats, the prevalence of the parasite in the primary host is relatively low. The intensity of metacercariae in the cockle was 3.3 (range 1-37) and of adults in the bird 125.7 (range 1-480). The habitat and biology of the primary and intermediate hosts and the behaviour and diet of the final host are discussed in relation to the transmission and prevalence of the parasite. © 1979 Taylor & Francis Group, LLC.