Description of a new species of Thynnascaris Dollfus, 1933 (Nematoda: Anisakidae) from the stomach of the marine teleost fish Rachycentron canadus (Linnaeus).

A new species of the nematode genus Thynnascaris obtained from the teleost Rachycentron canadus (Linnaeus) is reported. A detailed examination of this specimen has allowed us to erect a new species Thynnascaris to accommodate the worm. It shows remarkable differences from other known species of Thynnascaris in respect of body size, length of the oesophageal appendix and intestinal caecum, location of nerve ring and excretory pore, on the papillae on the lips arrangement, type of the striations on the cuticle, vulva position, arrangement of caudal papillae and size of the spicules. The new species is designated as Thynnascaris shyamasundarii.