Author Correction: Agricultural landscapes and the Loire River influence the genetic structure of the marbled newt in Western France.

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Agricultural landscapes and the Loire River influence the genetic structure of the marbled newt in Western France.

Amphibians are particularly sensitive to landscape fragmentation. Potential barriers between breeding sites can negatively influence the dispersal of individuals and increase genetic structure between populations. In this study, we genotyped 10 microsatellites for 334 marbled newts (Triturus marmoratus) at 11 different locations in Western France. Samples were collected in different regions with contrasting agricultural landscapes (low and high proportion of arable land in the north and south, respectively). We found a strong genetic structure between the northern and southern sampling sites. Isolation by distance was recorded after 62 km, but within the northern region, little or no genetic structure was detected over large distances (up to 114 km). Genetic structure at shorter distance (43 km) was found between sites situated in landscapes with larger amounts of arable lands. A significant positive relationship was found between the pairwise genetic distance (Fst) between sites and the amount of arable land together with the distance between sites. Our results suggest that the Loire River might act as a corridor for the marbled newt, while arable land might act as a barrier. Finally, although a large city is located between sampling sites, no effect was detected on population structure.

UV wavelengths experienced during development affect larval newt visual sensitivity and predation efficiency.

We experimentally investigated the influence of developmental plasticity of ultraviolet (UV) visual sensitivity on predation efficiency of the larval smooth newt, Lissotriton vulgaris. We quantified expression of SWS1 opsin gene (UV-sensitive protein of photoreceptor cells) in the retinas of individuals who had developed in the presence (UV+) or absence (UV-) of UV light (developmental treatments), and tested their predation efficiency under UV+ and UV- light (testing treatments). We found that both SWS1 opsin expression and predation efficiency were significantly reduced in the UV- developmental group. Larvae in the UV- testing environment displayed consistently lower predation efficiency regardless of their developmental treatment. These results prove for the first time, we believe, functional UV vision and developmental plasticity of UV sensitivity in an amphibian at the larval stage. They also demonstrate that UV wavelengths enhance predation efficiency and suggest that the magnitude of the behavioural response depends on retinal properties induced by the developmental lighting environment.

Genetic seascape of the threatened Caribbean elkhorn coral, Acropora palmata, on the Puerto Rico Shelf.

It has been proposed that the elkhorn coral, Acropora palmata, is genetically separated into two distinct provinces in the Caribbean, an Eastern and a Western population admixing in western Puerto Rico and around the Mona Passage. In this study, the genetic structure of A. palmata sampled at 11 Puerto Rican localities and localities from Curaçao, the Bahamas and Guadeloupe were examined. Analyses using five microsatellite markers showed that 75% of sampled colonies had unique genotypes, the rest being clone mates. Genetic diversity among genets was high (HE = 0.761) and consistent across localities (0.685 to 0.844). FST ranged from -0.011 to 0.047 supporting low but significant genetic differentiation between localities within the previously reported Eastern and Western genetic provinces. Plots of genetic per geographic distances and significant Mantel tests supported isolation-by-distance (IBD) within Puerto Rico. Analysis with the software Structure favored a scenario with weak differentiation between two populations, assigning eastern Puerto Rican locations (Fajardo and Culebra), Guadeloupe and Curaçao to the Caribbean Eastern population and western Puerto Rican locations (west of Vega Baja and Ponce), Mona and the Bahamas to the Caribbean Western population. Vieques and San Juan area harbored admixed profiles. Standardized FSTs per 1,000 km unit further supported higher differentiation between localities belonging to different Structure populations, with IBD being stronger within Puerto Rico than on larger regional scales. This stronger genetic transition seems to separate localities between putative Eastern and Western provinces in the eastern Puerto Rican region, not around the Mona Passage.