A new nematode, Dichelyne alatae sp. n., is described on the basis of the worms recovered from the intestine of the whiting, Sillaginopsis panijus (Perciformes: Sillaginidae) from the estuary of the river Hooghly at Kalyani, West Bengal, India. Dichelyne alatae differs from congeners in having a small body size, deirids posterior to the oesophagus, short and wide caudal alae at the level of cloacal opening, unequal, alate spicules, a shield-shaped gubemaculum, a different number of caudal papillae and a conical tail with spines in its distal region.
A new nematode species, Pseudocapillaria indica sp. п., is described from the intestine of the freshwater fish Channa gachua (Hamilton) from Kerala, India. It resembles P. tomentosa (Dujardin, 1843), differing from it mainly in the structure of the proximal end of spicule, the shape and structure of the stichocytes and in having smaller eggs (size 0.036-0.048 x 0.023-0.027 mm) which have a different type of superficial structure. Pseudocapillaria indica is the first capillariid species described from freshwater fishes of India and from the whole Oriental Region.
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.
The seasonal changes of the nematode Camallanus anabantis Pearse, 1933, in the climbing perch (Anabas testudineus) from the freshwater swamps near Kalyani town, West Bengal, India were studied during the period from February 1988 to August 1989. The nematode exhibited a one-year cycle. Larvated females occurred in the fishes from October to February at a water temperature of 12“-29 °C. New infection of fishes occurred from February to May and occasionally in September. The fourth-stage larvae, the males, and the young females (without eggs), although irregularly, were found present throughout the year. Egg-laden females occurred in the fishes in August, October to February, and March.