Granulinema gen. n. a new dracunculoid genus with two new species (G. carcharhini sp. n. and G. simile sp. n.) from the bull shark, Carcharhinus leucas (Valenciennes), from Louisiana, USA

Two new species of dracunculoid nematodes, G. carcharhini sp. n. and G. simile sp. n., representing a new genus Granulinema gen. n. (Dracunculoidea: Micropleuridae) are described from the bull shark, Carcharhinus leucas, from Louisiana (Lake Borgne), USA; the site of their localization in the host is unknown (probably abdominal cavity). The nematodes of both species were found in tissue juice and only males, juvenile females and body fragments of more advanced but nongravid females were obtained. Granulinema gen. n. differs from Micropleura, the only other genus in the family Micropleuridae, mainly by the presence of marked, dark excretory corpuscles in lateral excretory canals, pointed tail in females, greater number (6) of postanal pairs of caudal papillae in males, and by the presence of conspicuous transverse cuticular ornamentations on the body surface of mature females. The two new species can be easily distinguished from each other by the length of their spicules (0.78-0.90 mm in G. carcharhini sp. n. and 0.20-0.36 mm in G. simile sp. n.); moreover, there are two pairs of preanal papillae in the male of G. carcharhini sp. n., while there are three pairs in G. simile sp. n.