Echinuria australis n.sp. and E. uncinata (Nematoda: Spirurida), parasites of ducks in New Zealand

Abstract

Echinuria australis n.sp. is described from material from a grey duck (Anas superciliosa) from Taitapu, Canterbury. It is distinguished from other species by its small size (3.6–4.5 mm), cordons extending to the middle of the muscular oesophagus, long spicules (589–653 µm) with bifurcate tips, and short spicules (179–194 µm) with squarish distal ends, which lack the transparent terminal flange characteristic of Echinuriu uncinata (Rudolphi) and have a prominent subterminal spur. The L4 stage is distinguished from the L4 of E. uncinata by the possession of anastomosed cordons that extend to the posterior limit of the sclerotised stoma. The nematodes were found in hypertrophied proventricular glands filled with a caseous secretion. Cavernous granulomas in the deeper layers of the proventricular wall characteristic of most E. uncinata infections were not seen. E. uncinata is recorded from mallard (Anas platyrhynchos) and grey ducks from several localities in Canterbury.