Leptomonas wallacei is a trypanosomatid that develops promastigotes and cystic forms in the gut of the hemipteran insect Oncopeltus fasciatus. Insect trypanosomatids are thought to be solely transmitted from one host to another through the ingestion of parasite-contaminated feces. However, here we show that L. wallacei cysts present on the eggshells of eggs laid by O. fasciatus can also act as ...

Healthy specimens of Colisa fasciatus exposed to sub lethal concentration of hexavalent chromium (4.8 mg/L) for 15 days revealed no significant alterations in any testicular architecture during its different phases. However, 30 days exposure revealed distarded shape of lobule and lobular wall, scattered interstitial leydig cells during preparatory phase of testicular cycle where as during spawn...

The effects of an increasing downriver pollution gradient on the reproductive system of Astyanax fasciatus were investigated in the Rio dos Sinos, RS. The comparison of mean oocyte diameters, gonadal indices and gonado-somatic relationships of specimens captured in polluted areas with individuals from unpolluted reference sites revealed a significant decrease of these parameters with increasing...

Restriction fragment length polymorphism (RFLP) analysis of mitochondrial DNA (mtDNA) was employed to characterize species and populations of Astyanax, a Neotropical freshwater fish genus. Samples of five species, A. altiparanae, A. fasciatus, A. lacustris, A. scabripinnis paranae and A. schubarti, from the Upper Paraná and São Francisco river basins were analyzed. Two out of the ten restrictio...

-An evaluation is reported of methods used to prepare mosses for analysis when required for monitoring metal pollution. Fontinalis antipyretica and Rhynchostegium riparioides taken from the River Ho~gne, Belgium, were used for the study. The stages in preparation studied critically were the storage of the moss after it had been collected from the river, washing, choice of which particular fract...

Age.?Minimum, 18 ; maximum, 34; average, 233. Presentation.?Vertex, 30 ; pelvic, 2 ; face, 1. Position.?Left occipitoanterior, 23 ; right occipito-posterior, 5 ; right occipitoanterior, 2; left mento-auterior, 1; left sacroanterior, 1; right sacro-posterior, 1. Duration of Labour.?First stage: Minimum, 4 h. 30 m.; maximum, 62 h.; average, 15 h. 5 m. Second stage : Minimum, 25 m.; maximum, 6 h.:...

Sağlam et al. recently argued that the Devil's Hole pupfish (Cyprinodon diabolis), a conservation icon with the smallest known species range, was isolated 60 kya based on a new genomic data set. If true, this would be a radically long timescale for any species to persist at population sizes <500 individuals, in contrast to conservation genetics theory. However, here we argue that their analyses...

The parasitic copepod Gauchergasilus euripedesi (Montú, 1980) Montú &amp;amp; Boxshall, 2002 was described from plankton samples and specimens found in four fish species the estuarine area of Patos Lagoon, state Rio Grande do Sul (RS), Brazil. Later, one different reported parasitized with G. same locality. Species Astyanax Baird Girard, 1854 ( henseli Melo Buckup, 2006 lacustris (Lütken, 1875)...

Interspecific competition between G. ashmeadi, G. triguttatus and G. fasciatus for GWSS egg masses was investigated in the laboratory using three experimental designs. Overall parasitism by G. ashmeadi was consistently higher (up to 76.0%) compared with G. triguttatus and G. fasciatus, for all three experimental designs. Exposing females to individual egg ages (1, 3 or 5 days) showed that G. as...