Echinorhynchus veli (George and Nadakal, 1978), an acanthocephalid worm infesting the estuarine flat fish, Synaptura orientalis, was collected from the Veli lake, Kerala. The parasite was recovered from the intestine of the host fish. The detailed surface morphology was studied with the help of scanning electron microscope. The study revealed a cylindrical, medially swollen proboscis with a flat apex, backward directed hooks, each with smooth surface, broad base, pointed tip and an epidermal elevation at the point of insertion. A pair of sensory pits was seen at the base of the proboscis. The neck was well developed with densely packed epidermal micropores. Paired sensory pits were seen at the base of the neck and a collar between it and the trunk. The epidermis of the trunk has microtriches and micropores. The female genital pore was circular, and terminal in an elevated orifice. In male, the copulatory bursa was directed ventrally, with well-defined rim and several sensory papillae.

Intensity of Echinorhynchusveli infection is more common in the fish. This study was conducted in department of Zoology, Mar Ivanios College, Nalanchira, Thiruvananathapuram, Kerala, India during the period of 2011-13. The fish samples were collected regular sampling of fish from Veli on the south-west coast of Kerala. In this state the winter season includes the months of January and February, followed by summer months of March, April and May. The rest of the year is the rainy season, which is divided into the South West Monsoon (June, July, August and September) and the North East Monsoon (October, November and December). The samples were collected and studied. In male and female the intensity of infection was high during the Monsoon season in the two annual cycles and low in summer and SW monsoon respectively. Echinorhynchusveli infection is more common in the rainy season.