Actus shamimi n. sp. (Nematoda: Mononchida) from the Andaman and Nicobar Islands, India, with a key to the species of Actus Baqri & Jairajpuri, 1974

Abstract

AbstractA new predatory nematode species, Actus shamimi n. sp., is described and illustrated. Actus shamimi n. sp. is characterised by medium body length, buccal cavity barrel-shaped with apex of dorsal tooth located at ca 80% from base of cavity and 3-6 subventral denticles present in each latero-subventral row, cardia triangular in shape, amphidelphic gonad with longer oviduct, vagina very short and with distinct pars refringens vaginae containing cuboidal sclerotised pieces, tail elongate-conoid, slightly arcuate ventrally with three caudal glands and prominent terminal spinneret opening. It is similar to A. baqrus but has a smaller body length; absence of advulval papillae and shorter tail. It also differs from A. neocaledonensis in the position of the dorsal tooth apex, length of tail and presence of caudal glands and spinneret. The new species also differs from A. conoidus in the larger buccal cavity; lower lip height; lower c′ value and in having a sphincter at the oviduct-uterus junction; and from A. minutus and A. salvadoricus by longer body, longer buccal cavity, presence of a much more anteriorly located dorsal tooth and much higher c value. The genus Actus is reported for the first time from the Andaman and Nicobar Islands, India. A key to species in the genus is provided.