The nematode, Camallanus xenentodoni Khan et Yaseen, 1969 recovered from the intestine of the fish, Xenentodon cancila (Ham.) from West Bengal, India was studied by light microscopy. Larval development of this nematode was also studied under laboratory conditions. Two cyclopoid copcpods, Mesocyclops crassus and M. leuckarti maintained at temperatures 28-31.5“C were infected with first-stage larvae from gravid females. In the haemocoelic cavity of the copepod the larvae moulted twice to attain third, infective stage and a phase of growth, development and morphometric changes occurred between the two moults. Detailed descriptions of the adult worms and the three larval stages are given. Data obtained from the morphological and metrical studies of the present adult worms are compared with those available on C. xenentodoni and another related species C. cancelai Gupta et Verma, 1978, which is considered as synonym of C. xenentodoni.
Gangesia parasiluri Yamaguti, 1934 (Cestoda: Proteocephalidae) is redescribed on the basis of adults obtained from the intestine of Silurus asotus Linnaeus (Teleostei: Siluridae) from Lake Suwa, Nagano Prefecture, central Japan. Its life cycle was studied in the field and laboratory. Rostellar hooks of the adults showed a wide variation in number, ranging from 35 to up to 57. Plerocercoids were found in the rectum of Chaenogobius urotaenia (Hilgendorf) and Rhinogobius brunneus (Temminck et Schlegel) (Teleostei: Gobiidae) from the same lake. Procercoids were formed in the haemocoel of Mesocyclops leuckarti (Claus) (Copepoda: Cyclopidae) 7 days post infection at 21-25°C. They developed into plerocercoids in the intestine of Pseudorasbora puntila pumila Miyadi (Teleostei: Cyprinidae), R. brunneus and S. asotus. Plerocercoids from naturally and experimentally infected fishes were fed to S. asotus, from which immature worms were recovered. It is considered that the life cycle involves three hosts: a copepod as the intermediate host in which procercoids are formed, small fish as paratenic hosts which retain plerocercoids and transport them into S. asotus, and S. asotus as the definitive host in which adults develop. Rostellar hooks of the adults were much fewer, much larger and arranged in fewer circles than those of the plerocercoids. It is suggested that the former are newly formed and replace the latter in an early stage of development of plerocercoids into adults in 5. asotus.
Eucoleus schvalovoj Kontrimavichus, 1963 (Nematoda: Capillariidae) is redescribed. The original description of this species was brief and inadequate in thal it was based on just a few specimens removed from the Eurasian otter, Lutra lutra (Linnaeus, 1758) in the Khabarovsk region, USSR. Detailed morphological study of several specimens of E. schvalovoj from the oesophagus of L. lutra from Spain revealed new characters, above all in males, and allows for a better characterisation of this species. Since its original description £. schvalovoj has only been recorded in Spain.
Proteocephalus macrophallus (Diesing, 1850), considered by several authors as species inquireruia, was recently found in Cichla ocellaris in Venezuela. This material is compared with voucher specimens from the same host (C. ocellaris) from Brazil, identified and redescribed as P. macrophallus by Woodland (1933). The specific status of P. macrophallus is confirmed. This species is characterized by: 1 ) the shape of the body, which is wide and short, 2) the absence of a neck, 3) the distribution of the vitelline follicles, which converge posteriorly to the ovarian lobes, and 4) the structure of the uterus, which is evacuated in the last proglottides and transformed to thick-walled diverticles apparently separated each from other. A neotype is designated.