Philometrid nematodes (Philometridae) from marine fishes off the northern coast of Australia, including three new species

Based on light and scanning electron microscopical studies, the following nine species of Philometridae (Nematoda: Dracunculoidea) are described from female worms parasitizing marine perciform fishes belonging to six families off the northern coast Australia (near Darwin): Philometra australiensis sp. n. from the swimbladder of the king threadfin Polydactylus macrochir (Polynemidae); P. epinepheli from the operculum of the orange-spotted grouper Epinephelus coioides (Serranidae); Philometra johnii from the gonad of the croaker Johnius sp. (Sciaenidae); P. macrochiri sp. n. from the sensory fin of P. macrochir; P. zabidii sp. n. from the ovary of the ninespine batfish Zabidius novemaculeatus (Ephippidae); Philometra sp. 1 and Philometra sp. 2 from the ovary of the Spanish flag snapper Lutjanus carponotatus (Lutjanidae) and the silver grunt Pomadasys argenteus (Haemulidae), respectively; Philometroides eleutheronemae from the ovary of the fourfinger threadfin Eleutheronema tetradactylum (Polynemidae); and Spirophilometra endangae from the pectoral fins of E. coioides. The new species P. australiensis is characterized mainly by the structure of the cephalic end, 14 minute cephalic papillae, absence of caudal projections and body length of gravid female (67 mm), P. macrochiri by the presence of a conspicuously large anterior oesophageal bulb, 14 very small cephalic papillae and the truncated posterior end of body without any caudal projections, whereas P. zabidii is characterized by the presence of distinct caudal projections, the number (14) and larger size and arrangement of cephalic papillae, a poorly developed anterior oesophageal inflation, the body length (114 mm) and the host family (Ephippidae). All above-mentioned species were recorded from Australian waters for the first time.