First finding of a male Aphanolaimus coomansi (Tsalolichin, 1988) in tropical areas

The rare aquatic nematode Aphanolaimus coomansi Tsalolichin, 1988 was found in some habitats in Costa Rican Conservation Areas, permitting additional taxonomical details to be added to the original description. The first desc ription of a male of the species is also given in this paper. The male's re levant characteristics include: 22 pairs of epidermal glands, reproductive system with single posterior reflexed testis, six preanal tuboid supplement s and long spicules, gubernaculum weakly cuticularized and tail region prov ided with well developed setae. A. coomansi is easy to distinguish from oth er South American species. Some useful diagnostic characteristics are the s mall body length, few number of body annuli, the origin of the lateral fiel d near the head end and short cephalic setae.