Two New Huffmanela Species, H. japonica n. sp. and H. shikokuensis n. sp. (Nematoda: Trichosomoididae), from Marine Fishes in Japan

Abstract

Two new species of trichuroid nematodes. Huffmanela japonica n. sp. and Huffmanela shikokuensis n. sp., are established on the basis of their egg morphology and biological characters; the eggs of both species occur in the musculature of marine fishes from the Inland Sea of Japan. The dark-shelled eggs of H. japonica are found locally in masses ("black spots") in the flesh of Upeneus bensasi (Temminck et Schlegel) (Mullidae, Perciformes) and are characterized mainly by their shape and size (58-69 x 26-30 microm), an aspinose superficial transparent envelope enclosing the egg proper, relatively small polar plugs, and by their thick egg wall (4-5 microm). The eggs of H. shikokuensis are also dark-colored and are found evenly distributed in the musculature of Stephanolepis cirrhifer (Temminck et Schlegel) (Monacanthidae, Tetraodontiformes); they are characterized mainly by their shape and size (78-90 X 36-45 microm), by a very thin and aspinose superficial transparent envelope, large polar plugs, and relatively thin egg wall (3 microm). Histological sections of the host's infected musculature showed the presence of H. shikokuensis nematodes inside the muscle cells and in the intercellular spaces. A key to Huffmanela species based on egg morphology is provided.