When faced with the risk of predation, tadpoles of many amphibian species are known to modify their phenotype. In this work we studied the effect of an exotic species, the red swamp crayfish (Procambarus clarkii), on the phenotype of two species of amphibians with different reproduction habitats: the Iberian painted frog, Discoglossus galganoi, that normally reproduces in temporary water bodies and the common toad, Bufo bufo, that reproduces in permanent water bodies. The responses were compared with the ones shown in the presence of a native predator, dragonfly (Aeshnidae) larvae. Behaviour, growth and morphology of tadpoles were monitored in a factorial experiment with five treatments. Our results showed that only the permanent habitat species altered its behaviour and life-history traits in the presence of P. clarkii; however, this was mediated by chemical cues from consumed conspecifics. Antipredator responses of B. bufo towards the exotic crayfish were similar to the ones towards the native predator, while D. galganoi responded to the dragonfly larvae but not to P. clarkii. This may be the result of infrequent colonization events of temporary habitats by the crayfish. Therefore, the consequences of the introduction of P. clarkii might be more serious for D. galganoi and other species living in temporary habitats. Species breeding in permanent habitats, more prone to having generalized antipredator responses, may be relatively protected against this exotic crayfish although the effectiveness of these responses still needs to be tested.
Protocols for the conservation of threatened plants are often constrained by the absence of data on germination ecology. However, seed bank managers periodically monitor the viability of stored seed collections using germination tests. Here, we argue that data from those tests can and should be used to provide information on germination requirements of threatened species. Twelve taxa endemic to Portugal were used as a test case to determine the effect of incubation temperature and pretreatments upon germination and to identify major factors eliciting germination and releasing dormancy. We achieved maximum germination percentages >95% for nine taxa. Temperature significantly affected the final germination and mean germination time in most taxa. Maximum and faster germination at cool temperatures (15 °C or alternate 20/10 °C) was the prevailing trend. Cold stratification improved germination in one species, suggesting physiological dormancy. Scarification increased the germination percentage of one species among those expected to exhibit physical dormancy. Seed bank data provided valuable information on germination ecology, which can be used in in-situ conservation and as a baseline for further germination studies. Given the increasing threats to plant diversity, accessibility to seed bank data are paramount.
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