Rhabdochona mexicana sp n. (Nematoda : Rhabdochonidae) from the intestine of characid fishes in Mexico

A new nematode, Rhabdochona mexicana sp. n., is described based on specimen s recovered from the intestine of two species of fishes, Astyanax mexicanus (De Filippi) (type host) and Astyanax fasciatus (Cuvier) (Characidae: Char aciformes) in central Mexico. This species is characterised by the followin g characters: 10 anteriorly directed teeth in the prostom, a larger (left) spicule which is slender in form with a small bifurcation at its distal tip covered by a cuticular membrane, a smaller (right) spicule without a barb at its distal tip, eggs bearing an irregular flock-like coating, and a coni cal tail without a cuticular spike (in both sexes).