Efecto de la reubicación de nidos en el éxito reproductivo de la tortuga marina Lepidochelys olivacea (Testudinata: Cheloniidae) / Effect of nest relocation on the reproductive success of the marine turtle Lepidochelys olivacea (Testudinata: Cheloniidae)

Resumen Introducción: Para incrementar el número de crías de tortugas marinas, es necesario mejorar estrategias de conservación, como incubación de nidos, en condiciones de vivero que contrarresten los efectos de las condiciones climáticas extremas. Objetivo: Comparar cinco parámetros de éxito reproductivo (éxito de eclosión, huevos sin desarrollo aparente, crías muertas, mortalidad embrionaria y período de incubación) de la tortuga marina Lepidochelys olivacea. Métodos: Se evaluó la incubación de nidos bajo dos períodos de reubicación de nidos (P1 ~28.8 °C agosto-septiembre y P2 ~27.1 °C octubre-noviembre, temperatura ambiental promedio, bajo condiciones de vivero, en el 2018 en Guerrero, México. Resultados: Se encontraron diferencias significativas en el éxito de eclosión y la mortalidad embrionaria entre los períodos de reubicación de nidos (P < 0.001). En P1, se observaron valores más bajos de éxito de eclosión (77.0 % P1 vs 88.6 % P2) y valores más altos de mortalidad embrionaria (13.7 % P1 vs 3.3 % P2) comparados con los de P2. Es importante señalar que, en el presente estudio la mortalidad embrionaria se presentó en una etapa tardía de desarrollo, es decir, en embriones casi completamente desarrollados. No se encontraron diferencias entre periodos respecto a los parámetros de huevos sin desarrollo aparente, crías muertas y período de incubación. Conclusiones: Las diferencias entre las condiciones ambientales durante el primer período de reubicación de nidos en comparación con el segundo período parecen afectar el éxito de eclosión y mortalidad embrionaria de L. olivacea. Por lo tanto, es importante tomar medidas al respecto durante esta etapa de incubación para tratar de mejorar la incubación de nidos bajo condiciones de vivero.

Abstract Introduction: In order to increase the number of sea turtle hatchlings, it is necessary to improve conservation strategies, such as nest incubation in hatchery conditions that counteract the effects of extreme climatic conditions. Objective: To compare five reproductive success parameters (hatching success, eggs with no apparent embryonic development, dead hatchlings, embryonic mortality, and incubation period) of the sea turtle Lepidochelys olivacea. Methods: The incubation of nests was evaluated under two periods of nest relocation, P1 ~28.8 °C (August and September) and P2 ~27.1 °C (October and November), average ambient temperature, under hatchery condition, in 2018 in Guerrero, Mexico. Results: Significant differences were found in hatching success and embryonic mortality between nest relocation periods (P < 0.001). In P1, lower values of hatching success (77.0 % P1 vs 88.6 % P2) and higher values of embryonic mortality (13.7 % P1 vs 3.3 % P2) were observed compared to those of P2. It's important pointing that, in the present study, embryonic mortality occurred at a late stage of development, that is, in almost fully developed embryos. No differences were found between periods regarding the parameters eggs with no apparent embryonic development, dead hatchlings and incubation period. Conclusions: The differences between the environmental conditions during the first period of nest relocation compared to the second period, respectively, seem to affect the hatching success and embryonic mortality of L. olivacea. Therefore, it is important to take action on this issue during this incubation stage to try to improve the incubation of nests under hatchery conditions.

Diversity of Epibionts Associated with Lepidochelys olivacea (Eschscholtz 1829) Sea Turtles Nesting in the Mexican South Pacific.

The present study contributes to the knowledge of epibionts recorded on sea turtles that nested on a beach in the South Pacific of Mexico. A total of 125 Lepidochelys olivacea turtles nested on Llano Real beach, Guerrero, Mexico, were examined. We collected 450 conspicuous organisms from 8 species from 43 turtles. The corresponding data analysis was carried out to obtain the relative abundance, the relationship between turtle sizes and the presence of organisms, the similarity of species between the sampling months, and the interspecific relationships between the epibionts and the turtles observed. Chelonibia testudinaria was the most abundant species, while Remora remora was the least abundant species. The turtles were divided into six body sections, with the greatest abundance of these organisms located in the head-neck section of turtles, and there was a significant difference in the size of the turtles that presented epibionts and those that did not. C. testudinaria showed greater similarity between sampling months, and the interspecific relationships recorded were commensalism, parasitism, amensalism, and protocooperation. This research contributes the first record of epibionts in L. olivacea nesting in Guerrero, Mexico.

Temporal variation in infection levels and reproductive traits of the acanthocephalan Pseudoleptorhynchoides lamothei in the blue sea catfish Ariopsis guatemalensis (Günther, 1864).

Current data on reproductive biology and population dynamics of the acanthocephalans are scarce mainly in regions from the tropical Pacific. An analysis was done to identify possible factors that influence variation in infection levels of the acanthocephalan Pseudoleptorhynchoides lamothei Salgado-Maldonado, 1976 in its final host, the blue sea catfish Ariopsis guatemalensis (Günther, 1864), and describe its main reproductive traits. A total of 1,094 A. guatemalensis were collected from Tres Palos Lagoon from August 2014 to December 2015. Prevalence of P. lamothei varied from 1.47% to 38.33%, and mean abundance from 0.03 to 4.44 helminths per examined host. In female P. lamothei relative fecundity increased with total length. Temporal variations in P. lamothei infection levels were attributed mainly to changes in host feeding and reproductive behaviour in response to local environmental factors as climatic season, and variations in water temperature.