PARASITICS INDEX AND MORFOLOGICAL DESCRIPTION OF Contracaeum sp. (NEMATODA: ANISAKIDAE) IN TRANSANDEAN SHOVELNOSE CATFISH Sorubim cuspicaudus (PIMELODIDAE) FROM SINÚ RIVER BASIN

Objective. To determine the presence of parasites in trans-andean shovelnose catfish Sorubim cuspicaudus. Materials and methods. 33 fishs were collected between April and December 2007; at the laboratory internal and external recognition, inspection and dissection of visceral cavity was carried out. The nematodes found were preserved in 5% glycerolformal, after, they were clarified, the internal structures displayed for meristical and identification was based on morphometric keys. For scanning microscopy (JEOL JSM-5910LV at an accelerating voltage of 15 kV) the parasites were transferred to 4% formaldehyde and then fixed in osmium tetroxide, dehydrated with ethanol series and covered with a film of gold (6-8nm) by electro-deposition (Denton Vacuum Desk II). Results: Nematodes were found only in the visceral cavity and identified as Contracaecum sp. in larval III state, of whitish color, two lips in the previous end, a cuticular conical tooth and slightly bluntly. The rear part is conical, with two attached glands, anus and mucro; tail post-anal is long without terminal spine. The prevalence of this parasite was of 96.9% and in all cases with slight infestation. Of the total samples analyzed, males (n=9) presented parasitic intensity of 24.88±18.70 parasites/fish; whereas females (n=24) presented a parasitic intensity of 69.52±22.77 parasites/fish. Conclusion. Contracaecum sp. was found in visceral cavity of trans-andean shovelnose catfish in larval III state.