title: A new species of Allocreadium (Trematoda: Allocreadiidae) from freshwater fishes in the Danjiangkou Reservoir in China.
abstract: A new species of Allocreadium, Allocreadium danjiangensis n. sp., is described from the intestine of several species of freshwater fish, including Abbottina rivularis (Basilewsky, 1855), Sarcocheilichthys nigripinnis nigripinns (Güther, 1873), Gnathopogon argentatus (Sauvage et Dabry 1874), Opsariichthys uncirostris bidens (Gunther, 1873), and Erythroculter mongolicus mongolicus (Basilewsky, 1855) (Cyprinidae) from the Danjiangkou Reservoir in central China. The main morphological characters of the new species are as follows: vitelline follicles numerous, extending from the level of acetabulum to posterior extremity, distributed over both sides around the ceca; cirrus sac relatively large, developed, lying obliquely anterior to the acetabulum, extending from the level of the intestinal bifurcation to the central level of acetabulum, and overlapping left or right cecal; and ovary much smaller than testes, generally close to or even overlapping the anterior border of anterior testis. Observation by scanning electron microscopy shows only 2 kinds of tegumental formations, i.e., papillae and tubercles, instead of 3 types of tegumental formations, i.e., papillae, bosses, and minute sensor receptors observed on other species of the Allocreadiidae. The tegumental striations of the present species vary on the different parts of the body. In addition, a new structure, identified as the "groove" with a tonguelike tubercle, was observed on the inner wall of acetabulum.
authors: State Key Laboratory of Freshwater Ecology and Biotechnology, and Fish Immunology and Parasitology Group of the Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei Province, PR China.
authors: Dian
authors: D
authors: Gao
authors: Gui Tang
authors: GT
authors: Wang
authors: Bing Wen
authors: BW
authors: Xi
authors: Wei Jian
authors: WJ
authors: Yao
authors: Pin
authors: P
authors: Nie
mesh_terms: D000818:Animals; D002681:China; D005393:Fish Diseases / Q000469:parasitology*; D005399:Fishes; D005618:Fresh Water; D008855:Microscopy, Electron, Scanning / Q000662:veterinary; D014200:Trematoda / Q000145:classification* / Q000302:isolation & purification / Q000648:ultrastructure; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary*