Trematodes have complex life cycles with infective stages in multiple hosts including species of conservation concern. We conducted a field survey of seven ponds in Teton County, Wyoming for trematode prevalence and richness. We collected snails from each location and determined trematode prevalence by shedding snails and determined trematode richness by dissection of infected snails. At each l...

The genetic diversity of trematodes within second intermediate hosts has important implications for the evolution of trematode populations as these hosts are utilized after the parasites reproduce asexually within first intermediate hosts and before sexual reproduction within definitive hosts. We characterised the genetic clonal diversity of the marine trematode Maritrema novaezealandensis with...

The influence of latitude, substrate type, tidal level, and host shell size on trematode species-richness and prevalence were assessed using published data on 255 samples from 54 species of marine intertidal gastropods. The analyses were performed at different levels of statistical independence: among all samples, across snail species, and using phylogenetically independent contrasts. Repeatabi...

Geographic variability in abundance can be driven by multiple physical and biological factors operating at multiple scales. To understand the determinants of larval trematode prevalence within populations of the marine snail host Littorina littorea, we quantified many physical and biological variables at 28 New England intertidal sites. A hierarchical, mixed-effects model identified the abundan...

Meningoencephalitis caused by aberrant trematode migration is described in two California sea lions (Zalophus californianus) admitted to a rehabilitation hospital between May and August 2001. Both animals displayed seizure activity and were euthanized due to poor response to therapy. Gross abnormal findings included liver flukes (Zalophotrema hepaticum) in the bile ducts and areas of swelling a...

Infection by trematode parthenitae (larval, asexual trematodes) has severe consequences for molluscan hosts, resulting in cessation of reproduction and early mortality. Here we present evidence that the freshwater snail Planorbella trivolvis can lose infections by trematode parthenitae. Of 8 P. trivolvis infected by reniferin parthenitae, 6 died within 2 wk, whereas the remaining 2 snails lost ...

Pesticides can elevate trematode infections in amphibians. However, direct adverse effects of pesticides on embryos and free-living stages of trematodes have not been thoroughly explored, despite the potential for these effects to reduce amphibian trematode infections. We measured the effects of atrazine, glyphosate, carbaryl, and malathion on embryo and miracidium (free-living stage) survival ...

Juga yrekaensis freshwater snails were tested for trematode stages and for Ehrlichia risticii DNA using a nested PCR assay. Snails were collected monthly from two Potomac horse fever (PHF) endemic locations in northern California (Montague and Weed). The trematode infection rate varied between 40 and 93.3% in large snails (shell size >15mm) and between 0 and 13.3% in small snails (<15mm). The h...

Life history traits expressed by organisms vary due to ecological and evolutionary constraints imposed by their current environmental conditions and genetic heritage. Trematodes often alter the life history of their host snails by inducing parasitic castration. Our understanding of the variables that influence the resulting changes in host growth, fecundity and survivorship is insufficient to c...

background: a known species lutztrema (lutziella) microacetabularae rhode, 1966 is being described for the first time from pakistan. this species is characterized by having body long and slender, oral sucker subterminal, acetabulum smaller than oral sucker lying in anterior third of the body, pharynx small, esophagus promi-nent which become gradually wider and bifurcates in to two rudimentary c...