A total of 107 leptodactylid frogs representing 6 species, Leptodactylus fuscus (n 5 15), Leptodactylus leptodactyloides (n 5 9), Leptodactylus mystaceus (n 5 2), Leptodactylus ocellatus (n 5 31), Leptodactylus petersii (n 5 31), and Leptodactylus pustulatus (n 5 19), collected in the Brazilian state of Tocantins, were examined for helminths. One species of Digenea (Catadiscus marinholutzi), 6 ...

Halipegus eschi n. sp. is described from the esophagus of Rana vaillanti from Guanacaste Province, Costa Rica. The new species differs from other known species of Halipegus on the basis of relative testis size, lateral extent of the uterus, vitelline follicle arrangement, egg size, and polar filament length.

Quantitative fecal egg counts represented as the number of eggs per gram of feces (EPG) are generally a reliable parameter to estimate the worm burden of intestinal and hepatic parasitoses. Although Haplorchis taichui (Digenea: Heterophyidae) is one of the most common minute human intestinal flukes, little is known about the relationship between EPG and the actual worm burden in patients or the...

A new echinostome cercaria, Cercaria kuwaitae XI sp.n., from the prosobranch gastropod Cerithidea cingulata (Gmelin) from Kuwait Bay is described. The new cercaria is characterized by 23 collar spines and primary excretory tubules with distinct diverticula. The cercaria encysts in the snail host and is similar to those of Acanthoparyphium sp. The surface topography of the redia, cercaria and me...

MCKINDSEY, C.W., and MCLAUGHLIN, J.D. 1994. Transmission of Cyclocoelum mutabile (Digenea) to snails: the influence of temperature on the egg and miracidium. Can. J. Zool. 72: 1745 175 1. This study examined the survival and hatching dynamics of eggs of the digenean Cyclocoelum mutabile and the survivorship and infectivity of the miracidia under different temperature regimes. Hatching did not o...

The mature spermatozoa of Stephanostomum murielae and Stephanostomoides tenuis are described by transmission electron microscopy. They present several ultrastructural features previously reported in other digeneans. Their spermatozoa possess two axonemes of different length showing the 9 + '1' trepaxonematan pattern, four attachment zones, two mitochondria (with an anterior moniliform one in S....

The present study analysed the taxonomic status and phylogenetic relationships of two species of xiphidiocercariae of the 'microcotylae' group, Cercaria pugnax La Valette St. George, 1855, from Viviparus viviparus (Linnaeus) in the Ukraine and Cercaria helvetica XII Dubois, 1928 from Bithynia tentaculata (Linnaeus) in Lithuania. Molecular phylogenetic analyses based on sequences of the ITS2 reg...

The ultrastructural organization of the mature spermatozoon of the digenean Atractotrema sigani (from Siganus lineatus off New Caledonia) was investigated by transmission electron microscopy. The male gamete of A. sigani exhibits the general morphology described in digeneans with the presence of two axonemes of different lengths showing the 9 + "1" pattern of the Trepaxonemata, a nucleus, two m...

Evolutionary trends in body size have been identified within several lineages, but not all have followed Cope’s rule, which states that average body size within a taxon tends to increase over time. In organisms such as parasites, space constraints may have shaped the evolution of body sizes, favouring small-bodied taxa capable of exploiting new niches. Here, the average adult body sizes of fami...