A New Species of \u3ci\u3eSyncuaria\u3c/i\u3e Gilbert, 1927 (Nematoda: Acuarioidea: Acuariidae) in the Wood Stork, \u3ci\u3eMycteria americana\u3c/i\u3e L. (Aves: Ciconiiformes: Ciconiidae) from the Área de Conservación Guanacaste, Costa Rica

Syncuaria mycteriae n. sp. (Nematoda: Acuarioidea) was collected under the lining of the gizzard of a wood stork, Mycteria americana L., from the Área de Conservación Guanacaste, Costa Rica. The new species can be distinguished from all known species of Syncuaria by having irregular dotted ornamentations on the caudal alae of males, a complex distal end of the left spicule comprising three protuberances, and a spicule ratio of 1:9.3. Preliminary phylogenetic analysis of 11 Syncuaria spp. based on 9 morphological characters produced two equally parsimonious cladograms with a consistency index of 85%, differing only in the placement of S. hargilae. The phylogenetic analysis suggests that the new species is the sister species of S. leptoptili, whose male members have a single protuberance on the left spicule. Furthermore, the analysis suggests that the plesiomorphic host group for the genus is Ciconiiformes, specifically Ciconiidae (host for 5 species), with two species occurring in Threskiornithidae (also Ciconiiformes), possibly as a result of cospeciation, and two species each occurring in Pelecaniformes and Podicipediformes, resulting from four episodes of speciation by host switching