MORPHOLOGY OF ADULTS AND IMMATURES OF THE ACANTHOCEPHALAN, POMPHORHYNCHUS FUHAIENSIS YUE, 1998 (ACANTHOCEPHALA: POMPHORHYNCHIDAE) FROM CYPRINID FISH IN NORTHWEST CHINA.

Adult specimens of Pomphorhynchus fuhaiensis were identified from common carp (Cyprinus carpio L.) in Ulungur Lake of northwest China, and acanthors, acanthellae, cystacanths dissected from Gammarus lacustris in a small tributary of Ulungur River for the first time. The acanthocephalans were also found in crucian carp (Carassius carassius L.), tench (Tinca tinca L.), oriental bream (Abramis brama orientalis Berg), and ide (Leuciscus idus L.) in the lake. This species is distinguished from other species in Pomphorhynchus by its large, spherical bulb and very long neck as well as by a cylindrical proboscis armed with 15-17 longitudinal rows of 9-12 hooks each. The anterior proboscis hooks are almost uniform in size and shape, the sixth hook in a short row and the seventh hook in long row decrease abruptly in size posteriorly with the last end hook being a little larger than the prebasal hook, and in a ring; posterior proboscis hooks much more widely spaced. Furthermore, the lemnisci are claviform. The mean neck:trunk ratio is about 0.5, which is larger than most other species in Pomphorhynchus. Females are larger than males. In males, the testes are in one-third to one-half of the trunk, equal, ovoid-spheroid, usually contiguous, and small relative to the body size, and there are 6 ovoid cement glands. Pomphorhynchus fuhaiensis is similar to Pomphorhynchus laevis but can be distinguished by the number of longitudinal rows of hooks. Pomphorhynchus laevis is armed with 18-20 longitudinal rows of 11-13 hooks, P. fuhaiensis is armed with 15-17 longitudinal rows of 9-12 hooks.