A new cucullanid species (Nematoda) from the freshwater fish Thorichthys helleri (Cichlidae) in Mexico

Abstract

A new nematode species, Cucullanus oaxaquensis n. sp., is described from specimens recovered from the intestine of Thorichthys helleri Steindachner, 1864 from the R Modelo, Los Chimalapas, state of Oaxaca, Mexico. It is characterized largely by possesing unusual features among Cucullanus spp., i.e., net-like sculpture on the surface of eggs, a pair of small papillae near tail tip of females and a small terminal sclerotized structure at tail tip of both males and females. This findig represents the fouth species reported from freshwater fishes in Mexico and the second for cichlid fishes.