FREE-LIVING DORYLAIMID NEMATODES FROM NATURE RESERVES IN COSTA RICA. THE GENUS <I>PACHYDORYLAIMUS</I> SIDDIQI, 1983

Resumo

Esquivel, A., P. Guerrero., R. Pena-Santiago and T. Powers. 2007. Free-living dorylaimid nematodes from nature reserves in Costa Rica. The genus Pachydorylaimus Siddiqi, 1983. Nematropica 37:317-333. A taxonomic study of three species, two known and one new, belonging to the genus Pachydorylaimus Siddiqi, 1983 from natural areas in Costa Rica is presented. Pachydorylaimus holovachovi sp. n. is described and can be distinguished by its body 0.90-1.00 mm long, lip region 14-17 æm wide, odontostyle 13-15 aem long, odontophore morphology with differentiated hyaline spindle-shaped area surrounding its junction to pharyngeal lining but lacking distinct basal flanges, total stylet length 35-44 æm, pars refringens vaginae absent, V = 43-47, female tail straight and tapering to an acute tip (57-78 æm, c = 12.5-15.8, c' = 2.0-3.0), and males unknown. Costa Rican populations of P. notabenus and P. schizodontus are compared with their respective original descriptions. Descriptions, measurements and illustrations (light microsccope pictures) are provided for the three species; a line illustration of P. holovachovi sp. n. is presented as well as SEM photographs of P. holovachovi and P. notabenus. Finally, a key to identification of Pachydorylaimus is given together with a compendium of their main measurements and ratios. Pachydorylaimus notabenus is a new record for Costa Rican nematode fauna.