Living in a multi-stressor world: nitrate pollution and thermal stress interact to affect amphibian larvae.

The interaction of widespread stressors such as nitrate pollution and increasing temperatures associated with climate change is likely to affect aquatic ectotherms such as amphibians. The metamorphic and physiological traits of amphibian larvae during the critical onset of metamorphosis are particularly susceptible to these stressors. We used a crossed experimental design subjecting Rana temporaria larvae to four constant rearing temperatures (18, 22, 26, 28°C) crossed with three environmentally relevant nitrate concentrations (0, 50, 100 mg l-1) to investigate the interactive and individual effects of these stressors on metamorphic (i.

Phenotypic variation in Xenopus laevis tadpoles from contrasting climatic regimes is the result of adaptation and plasticity.

Phenotypic variations between populations often correlate with climatic variables. Determining the presence of phenotypic plasticity and local adaptation of a species to different environments over a large spatial scale can provide insight on the persistence of a species across its range. Amphibians, and in particular their larvae, are good models for studies of phenotypic variation as they are especially sensitive to their immediate environment.

Progeny of Xenopus laevis from altitudinal extremes display adaptive physiological performance.

Environmental temperature variation generates adaptive phenotypic differentiation in widespread populations. We used a common garden experiment to determine whether offspring with varying parental origins display adaptive phenotypic variation related to different thermal conditions experienced in parental environments. We compared burst swimming performance and critical thermal limits of African clawed frog (Xenopus laevis) tadpoles bred from adults captured at high (∼2000 m above sea level) and low (∼ 5 m above sea level) altitudes.

Land cover, individual's age and spatial sorting shape landscape resistance in the invasive frog Xenopus laevis.

The description of functional connectivity is based on the quantification of landscape resistance, which represents species-specific movement costs across landscape features. Connectivity models use these costs to identify movement corridors at both individual and population levels and provide management recommendations for populations of conservation interest. Typically, resistance costs assigned to specific land cover types are assumed to be valid for all individuals of the population.

Ecophysiological models for global invaders: Is Europe a big playground for the African clawed frog?

One principle threat prompting the worldwide decline of amphibians is the introduction of nonindigenous amphibians. The African Clawed Frog, Xenopus laevis, is now one of the widest distributed amphibians occurring on four continents with ongoing range expansion including large parts of Europe. Species distribution models (SDMs) are essential tools to predict the invasive risk of these species.

Reproductive strategies of the kangaroo leech, Marsupiobdella africana (Glossiphoniidae).

The Kangaroo Leech, Marsupiobdella africana, is a hermaphroditic organism, with insemination taking place by the planting of a spermatophore on another leech. Spermatophores are mostly planted on the anterior of the recipient leech, but not always. Several spermatophores may be planted by different leeches on a single recipient.