Redescription and genetic characterization of Philometra lagocephali Moravec et Justine 2008 (Nematoda: Philometridae) from Lagocephalus lunaris (Bloch and Schneider) (Tetraodontiformes: Tetradontidae) in the South China Sea.

Philometra lagocephali Moravec et Justine, 2008 was redescribed using light and scanning electron microscopy based on the new material collected from the lunartail puffer Lagocephalus lunaris (Bloch et Schneider) (Tetraodontiformes: Tetradontidae) in the South China Sea. Our specimens are identical with the original description in the body size of gravid female, the width of cephalic and caudal end, the number and arrangement of cephalic papillae, the relative length of the oesophagus to body length, the size of ventriculus, the morphology of oesophageal bulb and posterior end, and the body size of larvae. In addition, specimens of P. lagocephali were also characterized using molecular methods by sequencing and analysing the small ribosomal DNA (18S rDNA) and mitochondrial cytochrome c coxidase subunit 1 (cox1) target regions. Phylogenetic analyses of genus Philometra base on 18S rDNA sequences was made using Mega 5.2. The results confirmed P. lagocephali is a valid species. It's the first molecular study of this species. These new morphological and molecular data contributed to a more precise and rapid diagnosis of this hitherto poorly known philometrid nematode.