Paronchocerca struthionus n.sp. (Nematoda: Filarioidea) from ostriches (Struthio camelus), with a redescription of Paronchocerca ciconiarum Peters, 1936 and a review of the genus

Abstract

Paronchocerca struthionus n.sp. (Onchocercidae: Splendidofilariinae) from the lungs of Struthio camelus L. (Struthionidae) from West Africa has a long, sacculate glandular oesophagus similar to that of Paronchocerca limboonkengi (Hoeppli and Hsü, 1929) n.comb. (= Lemdana limboonkengi), P. bambusicolae, P. tonkinensis, and P. sonini. It can be distinguished by delicate annular cuticular thickenings and, in the male, a preanal hypodermal swelling, three pairs of circumanal papillae, and the length of the right spicule in relation to the length of the tail. Also, lateral, postanal papillae are absent, although inconspicuous subterminal papillae are present. Paronchocerca ciconiarum Peters, 1936, the type species, is redescribed on the basis of material from the pulmonary arteries of Leptoptilus crumeniferus (Lesson) (Ciconiidae) from Uganda. Seventeen valid species are recognized in the genus. Paronchocerca sanguinisardeae, P. choprai, and P. badamii are regarded as species inquirendae and P. alii, as a species incertae sedis. Among larger avian filarioid genera, Paronchocerca appears unique in that each species seems restricted to a single family of birds. Paronchocerca may have become established in early Ornithurae and subsequently persisted in some of the "primitive" birds, as well as having transferred to "modern" groups which now occupy the aquatic adaptive zone originally occupied by the earliest Ornithurae. Paronchocerca apparently has been largely unsuccessful in transferring to other modern groups.