Two new gonad-infecting species of Philometra Costa, 1845 (Philometridae), P. brevicollis sp. n. and P. mira sp. n., are described from the ovary of the brownstripe red snapper, Lutjanus vitta (Quoy et Gaimard) (Lutjanidae, Perciformes), from the South Pacific Ocean off the coast of New Caledonia. Based on light and scanning electron microscopy examination, these new nematodes are compared with all other gonad-infecting species of Philometra. The former species (males and mature and gravid females available) mainly differs from its congeners in the length of males (5.39-5.92 mm), equally long spicules (279-312 µm), and the gubernaculum (151-168 µm), in that the distal end of the gubernaculum bears dorsolateral transverse lamella-like structures, and in the structure of the male caudal end. The latter species (only males available) is characterized by the length of males (3.47-3.66 mm), equally long spicules (96-105 µm), and the gubernaculum (78-84 µm), the absence of a dorsal reflected barb or lamella-like structures on the distal end of gubernaculum, and by the structure of the male caudal end. Judging from the occurrence in the host, P. brevicollis is the main philometrid parasitizing the gonads of L. vitta, in which it can reproduce, whereas this fish probably serves as only the paradefinitive host for P. mira. Both P. brevicollis and P. mira are the first nominal species of Philometra described from fishes of the family Lutjanidae.
Two new nematode species, Philometra strongylurae sp. n. and Philometra tylosuri sp. n., are described from female specimens collected from needlefishes (Belonidae, Beloniformes) off the Fao coast, Basrah, Persian Gulf, in Iraq. Philometra strongylurae (gravid females with larvae) was recorded from the subcutaneous tissue, muscles of beak and gills of Strongylura leiura (type host) and S. strongylura, whereas P. tylosuri (nongravid females) from the musculature and the subcutaneous tissue of Tylosurus crocodilus. The former is characterized mainly by the presence of eight markedly large cephalic papillae, conspicuously large anterior oesophageal bulb and by the length of body (15-20 mm); the latter by eight minute cephalic papillae, poorly developed oesophageal bulb and by the body length (46-72 mm). A key to Philometra spp. with gravid females parasitic in the subcutaneous tissue, fins or musculature of fishes is provided.
Gravid females of two species of philometrid nematodes (Philometridae) were collected from marine perciform fishes in Japanese waters, mainly from the southern Sea of Japan. Based on light microscopy and scanning electron microscopy examinations, the previously described but poorly known species Philometra cryptocentri Yamaguti, 1961 is redescribed from specimens recovered from the abdominal cavity of Acanthogobius flavimanus (Temminck et Schlegel), Pterogobius elapoides (Günther) and P. zonoleucus Jordan et Snyder (all Gobiidae) (all new host records); the number (14) and arrangement of cephalic papillae in this species are described for the first time. The new species, Philometroides branchiostegi sp. n. from head tissues of Branchiostegus japonicus (Houttuyn) (Malacanthidae), based on a single specimen, is mainly characterized by the embossment of the entire body except for the cephalic end, presence of four submedian pairs of large cephalic papillae of external circle and two small lateral single papillae of internal circle, pair of large papilla-like caudal projections, the oesophagus with a distinct anterior inflation, by a markedly small body (length about 18 mm) and the larvae 306-465 µm long.
The first ultrastructural description of Ceratomyxa tenuispora Kabata, 1960 (Myxozoa, Bivalvulida) from Madeira Island (Portugal), a parasite found in the gall bladder of the commercially important black-scabbard fish, Aphanopus carbo Lowe is presented. This parasite possesses spherical to ellipsoidal disporous trophozoites. Spores have a central crescent-shaped body averaging 11.0 µm in length, 28.5 µm in thickness and 12.1 µm in width. The valves have two long opposite lateral processes (ribbon-like structures or tails), each averaging 173 µm in length. The total thickness of the spore averages 375 µm. The spore has two sub-spherical polar capsules (∼5.2 × 4.1 µm), each with a polar filament with 7 to 8 coils. Some ultrastructural aspects of the sporogonic stages are described. The trophozoites develop without contact with epithelial cells. The cytoplasmic membrane has numerous evenly distributed external slender projections about 0.3 to 0.7 µm long. The sporogenesis produces two spores without pansporoblast formation. In the matrix of the capsular primordium, microtubules with an unusual organisation were observed. A binucleate sporoplasm that contains several sporoplasmosomes and dense bodies fills the spore cavity and extends to the tails without penetrating them.