A SURVEY ON THE HELMINTHES OF BIRDS FROM BAI-YANG-DIEN LAKE, HOPEH PROVINCE, CHINAI. NEMATODES

The material for the present study was collected from Bai-Yang-Dien (a great lake in Hopeh Province), in March, April, October and November, 1964. After an examination of 462 birds belonging to 47 species, 186 birds (40.25%) were found to be infected by nematodes. Twenty-three species of parasitic nematodes, belonging to 10 families and 15 genera have been identified. Among them, one is found to be new to science and nine are recorded for the first time from China. In addition, 16 species of birds are found to be new hosts of the uematodea. An. inventory of the nematodes so far found in this surrey and a revised key to the species of the genus Epomidiostomum are given in the Chinese test, and the new speeies is herewith described as follows:Epomidiostomum subquadratum sp. nov.Body filiform, with fine transversely striated cuticle but without wrinkled cuti-cular neck-region. Head bearing a subquadrate plate consisting of four petal-like projections, each of which possesses an indentation at the apex. Mouth opening top-shaped, surrounded by six head-papillae, four submedium and two lateral in position.MALE Body 6.02-6.53 mm in length and 0.138-0.206 mm in width. Oesophagus club-shaped, 0.840-0.946 mm in length and 0.051-0.068 mm in width. Anterior end to nerve ring 0.170-0.206 mm, to excretory pore 0.310 mm. Bursa well developed, with 2 large lateral and 1 small dorsal lobes, the lateral lobes being marked with numerous droplet striations on the membrane and the dorsal one with transverse striations. Ventral and lateral rays radiating from the main stalk, the latero-ventral and ventro-ventral rays being equal in size and extending to the margin of the lateral lobe. Anterio-lateral ray short and thick; inedio-lateral and posterio-lateral rays almost equal in size, and extending also to the margin of the lateral lobe. External dorsal 0.051-0.068 mm in length, separated from the main stalk at the base and extending to the margin of the bnrsa. Dorsal ray 0.048-0.059 mm in length, and divided distally into 4 small branches, the 2 outer branches being shorter than the inner ones. Spicules one pair, brown in color, similar in shape, 0.139-0.156 mm in length, proximal end 0.013-0.017 mm in width, without a prominent button-like structure. Each spicule divided at the middle into 3 branches, 0.058-0.088 mm in length, 0.010 mm in width and surrounded by a membranous structure, the distal end of the main branch being tridigitate.FEMALE Body 6.192-8.600 mm in length and 0.189-0.258 mm in width. Oesophagus 0.722-0.894 mm in length. Anterior end to nerve ring 0.292 mm. Vulva slit-shaped, slightly protruded. Posterior end to vulva 2.430-2.460 mm, to anus 0.154-0.206 mm. Body narrowing rapidly behind the anus and bent ventrally. Ova in uterus 0.076-0.083 mm in length and 0.048-0.055 mm in breadth.HOSTS Anas falcata Georgi, A. penelope Linne, A. s. strcpera Linne, A. poeci-lorhyncha zonorhyncha Swinhoe, A. querquedula Linne, A. c. crecca Linne, and Netta rufina (Pallas).LOCATION Gizzard.LOCALITY Bai-Yang-Dien Lake, Hopeh Province, China.TYPES Holotype , allotype , paratypes 4 , 4 , all deposited in the Institute of Zoology, Academia Sinica, Peking, China.