Previously undescribed third-stage larvae of two species of Spirurida were found in the haemocoel of the stalk-eyed mud crab Macrophthalmus hirtipes (Heller) (Ocypodidae) in New Zealand. Examinations by light and scanning electron microscopy showed that the larger larvae (about 7 mm long) belonged to a species of Ascarophis van Beneden, 1871 (Cystidicolidae), the genus including parasites of fishes, whereas the smaller larvae (about 4-5 mm long) belonged to the Acuariidae, a family with species parasitic as adults mostly in aquatic birds. In a sample of 82 specimens of M. hirtipes collected in July 2002 from Papanui Inlet, on Otago Peninsula, South Island, 74 crabs (90.2%) were infected with larval nematodes with an intensity of 1-18 (mean 4.6) nematodes per crab; no distinction between nematode species was made in these estimates, although juvenile Acuariidae greatly outnumbered larval Ascarophis. Apparently, crabs play a role as intermediate hosts of these nematode species. This is the first record of larval representatives of Cystidicolidae and Acuariidae from invertebrates in the Australasian Region.
A new nematode genus and species, Lucionema balatonense gen. et sp. п., is described from the swimbladder of the European pikeperch, Stizostedion lucioperca (L.), from Lake Balaton in Hungary; a new dracunculoid family Lucionematidae fam. n. is established to accommodate it. The hitherto monotypie family Lucionematidae shows affinities with the families Skrja-billanidae and Daniconematidae, differing from them mainly in having simple oesophagus without external oesophageal glands and the vulva situated near the middle of body; from the first family also in the absence of the buccal capsule and the bursa-like caudal alae in the male. The genus Lucionema gen. n. is characterized mainly by the presence of 8 cephalic papillae in two circlets, absence of spicules, presence of the copulatory plate, only 2 pairs of postanal papillae in the male, and by the distal part of the monodelphic uterus forming a posteriorly directed coil. The body length of L. balatonense females is 1074-1782 pm, that of the only available male 770 pm. A key to the families of the Dracunculoidea is presented.
Two new species of philometrid nematodes (Philometridae) from needlefishes (Belonidae) in Florida are described based on morphological and genetic characteristics: Philometra aequispiculata sp. n. (males and females) collected from the ovary of Strongylura marina (Walbaum) (type host) and Strongylura notata (Poey), and Philometra notatae sp. n. (females) from the swimbladder of S. notata. Both species are described and illustrated based on light and scanning electron microscopical examinations. Morphologically, P. aequispiculata sp. n. differs from all congeners mainly in the unique structure of the distal tip of the gubernaculum, whereas P. notatae sp. n. is mainly characterised by the presence of eight markedly large cephalic papillae of the outer circle in gravid and subgravid females, the body length of the gravid female (54 mm) and by the absence of caudal projections. Molecular characterisation of the new species was assessed from phylogenetic analysis of mitochondrial cytochrome c oxidase I (COI) and SSU rRNA small-subunit ribosomal RNA (SSU) sequences among closely related philometrids by way of Bayesian inference. Phylogenetic reconstructions based on COI and SSU sequences show each of the new species comprise discrete ancestor-descendent lineages.
The morphology of two Salvelinema Trofimenko, 1962 species, S. salmonicola (Ishii, 1916) and S. walkeri (F.kbaum, 1935), swimbladder nematodes of salmonids, was studied in detail, including scanning electron microscopy (SEM), on the basis of newly collected materials from Oncorhynchus masou, О. mykiss and Salvelinus malma from Japan and from Oncorhynchus ciarki, О. kisulch and O. nerka from North America (Vancouver Island, B.C., Canada and Gulf of Alaska). Both nematode species proved to be morphologically very similar, differing substantially in the numbers and arrangements of egg filaments. Deirids were described for the first time for Salvelinema. Salvelinema iwana (Fujita, 1928), S. amemasu (Fujita, 1939), S. kosugii (Fujita, 1939), S. oncorhynchi (Fujita, 1939) and S. salvelini (Fujita, 1939) (= S. ishii (Fujita, 1941)) were synonymised with S. salmonicola. Comephoronema Layman, 1933 is re-erected as a valid genus related to Salvelinema.
A new nematode, Myleusnema bicumis gen. et sp. п., is described from the intestine of a characoid freshwater fish, Myleus ternetzi (Norman, 1929) (Cypriniformes: Serrasalmidae), from French Guiana. This cosmocercoid nematode species represents a new genus of the family Kathlaniidae, being characterized mainly by the shape of the body (the cephalic portion is separated from the rest of the body at the level of the nerve ring), structure of the cephalic extremity (presence of three lips and three lamella-like formations demarcating the buccal cavity), absence of an oesophageal pharynx, presence of medium-sized alate spicules (0.694-0.721 mm long), two conspicuous postcloacal homs associated with a gubernaculum, and by the number and distribution of caudal papillae in the male.