Halipegus eschi n. sp. (Digenea: Hemiuridae) in Rana vaillanti from Guanacaste Province, Costa Rica

SPECIES OF GORGODERINA (DIGENEA: GORGODERIDAE) IN RANA VAILLANTI AND RANA CF. FORRERI (ANURA: RANIDAE) FROM GUANACASTE, COSTA RICA, INCLUDING A DESCRIPTION OF A NEW SPECIES

Gorgoderina parvicava, G. diaster, and G. megacetabularis n. sp. are reported inhabiting the urinary bladders of Rana vaillanti and R. cf. forreri from northwestern Costa Rica. Gorgoderina megacetabularis n. sp. differs from all other species of the genus by the combination of the following characters: small body size (2.78-3.17, mean 2.92 mm), sucker ratio (1:3.1-3.7), and by the presence of 2 compact, oval, unlobed vitelline masses. Redescription of G. diaster including previously undescribed details on the reproductive apparatus and morphometric data is provided. This is the first record of the 3 species of Gorgoderina in Costa Rica and is the first record of G. diaster in R. vaillanti and R. cf. forreri.

HELMINTH INFRACOMMUNITIES OF RANA VAILLANTI BROCCHI (ANURA: RANIDAE) IN LOS TUXTLAS, VERACRUZ, MEXICO

A total of 76 adult individuals of Rana vaillanti were collected in Laguna Escondida, Los Tuxtlas, Veracruz, Mexico, and their helminth infracommunity structure was determined. Among the 21 helminth taxa collected (10 digeneans, 8 nematodes, and 3 acanthocephalans), the digenean Langeronia macrocirra reached the highest prevalence (64.4%), mean abundance (6.6), and mean intensity (10.4), as well as the highest total number of individuals (499). Only 2 frogs were uninfected, the remainder harbored between 1 and 7 helminth species and 1-102 individuals; mean species richness and abundance were 3.49 +/- 0.22 and 16.1 +/- 16.3, respectively. Langeronia macrocirra dominated in 50.6% of the infracommunities, with relatively low Berger-Parker index values (0.56); for this reason, the evenness was high (0.70 +/- 0.31), and consequently, diversity values are the highest recorded to date in species of Rana. However, patterns of helminth infracommunity richness and diversity were similar to those previously observed in amphibians. This structure is attributed to the feeding habits (between 66.7 and 81% of helminth species parasitizing R. vaillanti enter using the food web dynamics) and low vagility (the remainder species infect by host penetration).