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Based on light and scanning electron microscopical studies, two new and one specifically not identified gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from the ovary of marine fishes of the genus Epinephelus Bloch (Serranidae, Perciformes) in the Bay of Bengal, off the eastern coast of India: P. indica sp. nov. (male and females) from the honeycomb grouper E. merra Bloch, P. tropica sp. nov. (males and females) from the duskytail grouper E. bleekeri (Vaillant) and Philometra sp. (only females) from the cloudy grouper E. erythrurus (Valenciennes). Philometra indica is mainly characterized by the length of spicules 192–195 μm and the gubernaculum 84 μm, the distal tip of the gubernaculum without a dorsal protuberance, and by the presence of five pairs of caudal papillae. Philometra tropica is mainly characterized by the spicules conspicuously ventrally distended at their posterior halves, the distal tip of the gubernaculum with a dorsal protuberance, and the presence of three pairs of caudal papillae.
Investigations conducted off the northern Tunisian coast (central Mediterranean) allowed the authors to collect a male of the unicorn leatherjacket filefish, Aluterus monoceros (L.). The specimen is described in this note, including morphometric measurements and meristic counts. This finding constitutes the first record of A. monoceros off the Tunisian coast and the second record for the Mediterranean Sea. The occurrence of this species in the area and the Mediterranean Sea is discussed and commented.
Magnivitellinum corvitellinum sp. nov. is a parasite from the intestine of tamboatá Hoplosternum littorale, a freshwater catfish from Paraná River, Brazil. This species has an elongate body, a small cirrus-sac, testes in the posterior half of the body and well-developed follicular vitellines. It differs from the only other species in the genus, M. simplex, in having tegumental spines along the body, ventral sucker distinctly bigger than oral sucker, oesophagus absent and vitellaria extending from posterior margin of ventral sucker to near posterior extremity of body. An emendation of the generic diagnosis is proposed in view of the presence of tegumental spines along the body, absence of oesophagus, relative size of ventral and oral suckers and uterus covering caeca from the level of ventral sucker to the end of caeca. This is the fourth trematode species recorded parasitizing Hoplosternum littorale.
Aspects of the ecology of Brycinus nurse Ruppel, 1832 in the River Jamieson, Nigeria were studied. B. nurse constituted 19.8% of the characid catch and was unevenly distributed in the river with perennial occurrence in the downstream station. Peak abundance was at the beginning of the dry season. Fish size ranged from 7.0 to 19.0 cm standard length and weighed 40.5-171.0 g. The growth pattern was allometric. Condition factor ranged from 1.99 to 2.65 and varied with individual length of fish. Condition factor was slightly higher during the wet season. B. nurse fed primarily on plant fragments and seeds and Hymenoptera while algae and various alate insets were of secondary importance. Immature aquatic insects were incidental food items. B. nurse was essentially both day and night time feeder with only quantitative variations in dietary habits in relationship to size and season.
A new species of Acanthochondria (Copepoda, Poecilostomatoida, Chondracanthidae) parasitic on Brazilian codling Urophycis brasiliensis (Kaup, 1858) and the gulf hake U. mystaceus Ribeiro, 1903 from the Brazilian coastal zone, is described and illustrated. The new species of Acanthochondria differs from the other species of genus by a combination of characters that include shape of the head, shape of the trunk and size of the trunk posterior processes. This is the first record of Acanthochondria species from the South American Atlantic Ocean.
A new species of parasitic nematode, Philometra mexicana sp. nov. (Philometridae), is described based on males and females parasitizing the gonads of the marine perciform fish (rock hind) Epinephelus adscensionis (Osbeck) (Serranidae) off the coast of the southern Gulf of Mexico (reefs of the Enmedio Island, Veracruz), Mexico, collected on 10 April 1990. The new species is characterized mainly by very small males (body length 1.63–1.86 mm) with equally long, needle-like spicules (length 90–120 μm) and the gubernaculum (57–66 μm) without the usual dorsal barb on the distal end, the body length of gravid females (178–230 mm), the presence of a well-developed anterior bulbous inflation on the female oesophagus, and by the length of the first-stage larvae (420–435 μm). A comparison with other congeners parasitizing the gonads of marine fishes is provided. The cephalic end of the gravid female of Philometra margolisi Moravec, Vidal-Martínez et Aguirre-Macedo, 1995, another related species from the gonads of Epinephelus [E. morio (Valenciennes)] in Mexico, has been studied by SEM for the first time; it confirms the arrangement of the cephalic papillae as reported in the original species description. Philometra mexicana is the fifth species of Philometra reported from the gonads of marine fishes in the West Atlantic region.
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