1. Life histories of the highly diverse and endangered North American freshwater mussel fauna are poorly known. We investigated reproductive traits of eight riverine mussel species in Alabama and Mississippi, U.S.A.: Amblema plicata, Elliptio arca, Fusconaia cerina, iizmpsilis ornafa, Obliquaria refzexa, Pleurobema decisum, Quadrula asperata and Q. pustulosa, and compare our results with existi...

Heterozygote advantage, or overdominance, remains a popular and persuasive explanation for the maintenance of genetic variation in natural populations in the face of selection. However, despite being first proposed more than 80 years ago, there remain few examples that fit the criteria for heterozygote advantage, all of which are associated with disease resistance and are maintained only in the...

Bacteriophages (phages), the viruses of bacteria, form visible lesions within bacterial lawns (called plaques), which are employed ubiquitously in phage isolation and characterization. Plaques also can serve as models for phage population growth within environments that display significant spatial structure, e.g. soils, sediments, animal mucosal tissue, etc. Furthermore, phages growing within p...

Length-weight relationship, length at first maturity and sex ratio of the Nile perch Lates niloticus (L.) were studied from 342 fish samples collected between February 1995 and May 1996. The relationship between total length (TL) and total weight (TW) for both sexes was curvilinear and statistically significant. The regression equation for the males was TW=0.0044TL3.27 (r2=0.978, P<0.001) and t...

Experiments in laboratory populations of Drosophila melanogaster have shown a negative genetic correlation between early-life fecundity on the one hand and starvation resistance and longevity on the other. Selection for late-life reproductive success resulted in long-lived populations that had increased starvation resistance but diminished early-life fecundity relative to short-lived controls. ...