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.
A new nematode species, Pseudocapillaria yucatanensis sp. n., is described from the intestine of the freshwater pimelodid catfish Rhamdia guatemalensis (Günther) from cenotes (= sinkholes) in Yucatan, Mexico. It differs from other three related species parasitizing freshwater fishes mainly in possessing the spicule with a simple rim of its proximal end and a non-expanded distal end, in the length of the spicule (0.218-0.295 mm), and the size (0.050-0.060 x 0.025-0.030 mm), shape and structure of eggs, and also in the host types and geographical distribution. Pseudocapillaria yucatanensis is the first known autochtonous species of Pseudocapillaria parasitizing freshwater fishes in Mexico.
A new monogcncan species, Pseudorhabdosynochus capurroi sp. n., is described from the gills of the black grouper, Mycteroperca bonaci (Poey) (Serranidae), from the Yucatan Peninsula, Mexico. The new species can be differentiated from all other known species of Pseudorhabdosynochus Yamaguti, 1958 by being the largest one recorded until now (1162-1535 pm body length). Moreover, the vagina of P. capurroi has a small funnel-shaped opening with a non sclerotized vesicle from which a fine sclerotized duct leads proximally to a sclerotized seminal receptacle, and the testis is bilobate. The squamodiscs have 14 to 16 rows of rods, of which 3 to 5 rows are closed.
Pseudarhahdttsynachus yucatanensis sp. n. (Diplectanidae) is described from the gills of the red grouper, Epinephelus maria (Valenciennes, 1824) (Serranidae), from the coast of the Yucatan Peninsula, Mexico. This new species is characterized by having both the ventral and the dorsal squamodiscs composed of 10-12 rows of rods, with 0-1 innermost row forming a closed circle. Furthermore, the vagina of P. yucatanensis has a non-sclerotized ampulla with a fine, sclerotized duct leading to a sclerot-ized seminal receptacle. Prevalence (percentage of infected fish) and abundance (mean number of worms per examined fish) were estimated for P. yucatanensis from 8 localities along the coast of Yucatan. Prevalence varies from 38% to 100%, while abundance was between 1.2 ± 0.6 and 43.2 ± 17.8 worms per ftsh. The lack of linear relationship between the host length and the number of monogcneans per fish (regression F, = 0.56. p = 0.45) was probably due to the fact that the sample was restricted to juvenile hosts.