Metal bioaccumulation and its genotoxic effects on eggs and hatchlings of giant Amazon river turtle (Podocnemis expansa).

The aim of this study was to assess whether possible metal contamination in the sediment of the nests of giant Amazon river turtle, Podocnemis expansa, could contaminate eggs and hatchlings, triggering genotoxic damage. Therefore, sediments of P. expansa nests from two sites in the Brazilian Amazon were evaluated, with the first being collected at Araguaia River and the second at Crixás-Açu River. Newly hatched offspring, eggs, and sediments were collected from the beaches of these two rivers and the quantification of metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) was carried out by atomic absorption spectroscopy. All targeted metals were found in both sediment and P. expansa biological samples collected on the beaches presenting higher concentrations in the sediment of Crixás-Açu River. Metals found in the eggshells before nesting and in the egg contents were maternally transferred. Moreover, augmented concentration of metals led by metal transfer from the nests sediments were detected in the eggshells after nesting (ENH) and in the newly hatched offspring (H). Probably this metal relocation to the newly hatchlings augmented the frequency of micronuclei in their blood, presenting 15.25‰ in hatchling found in Crixás-Açu River beaches and 10‰ in newly hatched animals from Araguaia River beaches. These results indicate the occurrence of maternal transfer of metals (essential or not) to the eggs in testudines as well as a transference from the sediments to the nesting eggs, triggering genotoxic effects on the hatchlings.

Spatiotemporal variation in Lepidochelys olivacea sea turtle nests and their influence on the abundance and reproductive phenology of the sapro-necrophagous beetle Omorgus suberosus.

The olive ridley sea turtle, Lepidochelys olivacea (Eschscholtz, 1829), nests en masse in the protected natural area of La Escobilla, Mexico. On this beach, Omorgus suberosus (Fabricius, 1775), a sapro-necrophagous beetle, feeds on the sea turtles' decomposing and live eggs and is considered to be a threat for the conservation of L. olivacea. However, the abundance and reproductive phenology of O. suberosus in relation to the spatial and temporal availability of this food resource are unknown. We tested two alternative hypotheses during the 2013-2014 nesting season of L. olivacea: (i) abundance and female reproductive phenology of beetles are determined by the spatial and temporal availability of decomposing eggs that accumulate during the turtle nesting season, and (ii) abundance and female reproductive phenology of beetles are related to the increase in the concentration of seasonal and/or new turtle nests. Twenty-four plots (1 m2) were sampled in three areas with different turtle nesting densities. Spatially, beetle abundance was greater where turtle nest density was high and decomposed eggs were abundant. At the temporal level, old nests (> 45 days after egg deposition) were abundant and the presence of seasonal and new nests (~ 45 or fewer days after egg deposition) appeared to trigger sexual maturation in female beetles. Immature female beetles were more abundant throughout the turtles' nesting season, and mature females were only abundant during the turtle arribadas with the highest number of seasonal nests. We conclude that abundance and female reproductive phenology of O. suberosus females are influenced by the quantity and quality of the resource. These findings are useful to understand the interaction of L. olivacea with other species and to strengthen the conservation plans of this turtle species.

Estructura de tallas de tortuga pico de loro Lepidochelys olivacea (Testudines: Cheloniidae) en Tumbes, Perú

En el presente trabajo se analizó la estructura de tallas de ejemplares de tortuga pico de loro Lepidochelys olivacea, varados y capturados incidentalmente en las playas de Tumbes, Perú (3º389,5"S - 80º362,48"W y 3º5721,3"S - 80º5745,72"W), desde noviembre de 2006 a octubre de 2011. El área de estudio se dividió en tres zonas contiguas, limitadas por las quebradas más activas (Bocapán, El Rubio y Peña Negra). Se registraron 39 ejemplares (74,4% varados y 25,6% capturados incidentalmente), cuyas tallas variaron de 45 a 75 cm LCC (62,5±5,7 cm LCC). El 64,1% correspondió a individuos sub-adultos (<65 cm LCC; n = 25). Espacialmente la mayor cantidad de registros ocurrieron en las zonas 3 y 2, en las cuales porcentajes superiores al 60% se consideraron sub-adultos; mientras que en la zona 1, el 83% fue adulto. Temporalmente en la época lluviosa se registró la mayoría de las observaciones (59%), en la cual el 78,3% de ejemplares se consideró sub-adulto; siendo mayor que en la época seca (43,8%). Las tallas presentaron diferencias significativas entre zonas y épocas climáticas. Se corroboró el patrón de distribución latitudinal por estados de madurez aparente (más adultos en el norte). La presencia del componente adulto indicaría que el litoral de Tumbes sería una potencial zona de anidamiento de L. olivacea, con mayores probabilidades de ovoposición en época seca, corroborada por los eventos de anidamiento recientes.

In this paper we analyzed the size structure of Olive Ridley turtle Lepidochelys olivacea, from individuals stranded and incidentally caught in beaches of Tumbes, Peru (3º389.5"S - 80º362.48"W; 3º5721.3"S - 80º5745.72"W), since November 2006 to October 2011. The study area was divided into three contiguous areas, which were limited by the most active streams (Bocapan, El Rubio and Peña Negra). There were 39 individuals (74.4% stranded and 25.6% caught incidentally), with sizes ranged from 45 to 75 cm CCL (62.5±5.7 cm CCL). 64.1% was considered sub-adult individuals (<65 cm CCL, n= 25). Spatially the largest number of records occurred in zones 3 and 2, in which percentages above 60% were considered sub-adults, while in zone 1, 83% was adult. Temporarily in the rainy season were registered the majority of the observations (59%), in which 78.3% of specimens was sub-adult, being higher than in the dry season (43.8%). Sizes showed significant differences between zones and climatic seasons. It was confirmed the latitudinal distribution pattern by apparent maturity stages (more adults in the north). Adults occurrences suggest that Tumbes coast would be a potential nesting area of L. olivacea, most likely to oviposit in dry season, it which is supported by recent nesting events.