Influence of incubation temperature, maternal effects, and paternity on quality of olive ridley hatchlings (Lepidochelys olivacea) from a mass-nesting beach in the Mexican Pacific.

Future climate change scenarios project that the increase in surface temperatures will affect ocean temperatures, inducing shifts in marine biodiversity. Sea turtles are species that are particularly vulnerable to the effects of climate change because temperature is a factor that influences embryonic development. We collected clutches of olive ridley turtles from a mass-nesting beach in the Mexican Pacific, which were incubated in ex situ conditions. When the hatchlings emerged, we measured the body condition index-which evaluates the weight-length relationship-and swim thrust, both were considered traits associated with fitness, termed "fitness proxies," and evaluated the effects of incubation temperature, maternal effects, and paternity on these fitness proxies. The body condition index was correlated positively and significantly with the arribada month and temperature during the last third of the incubation period but showed an inverse relationship with the maternal effect. While swim thrust was positively correlated with the maternal effect and the arribada month, there was an inverse relationship with incubation temperature during the first third of the period. Paternity, whether single or multiple, did not have a significant effect on either fitness proxies; however, it may have effects on the average fitness of a population of hatchlings. These results underscore the need to expand research on the sublethal effects of high incubation temperatures on the adaptation and survival of sea turtles, particularly in scenarios of rapid climate change.

A morphological and morphometric approach to study Ophiuroidea (Echinodermata): Size changes of Ophiocomella alexandri.

Studies on size changes of Ophiuroidea are limited, despite their importance and implications in taxonomy, phylogenetics, ecology, and distribution. These studies have traditionally been based on descriptive size series seldom integrating quantitative analyses to assess the morphological variability of species, despite their potential use to study size changes in brittle stars. To confirm the latter, size changes of Ophiocomella alexandri were studied here using this approach. The studied size series of O. alexandri included specimens from 1.64 to 23.64 mm disc diameter (DD). Quantitative and qualitative external morphological characters were examined on each specimen, and quantitative analyses (cluster, one-way permutational analysis of variance, and discriminant analysis) were employed to identify size groups within the species. The allometric relationship disc diameter-total arm length (DD-AL) was estimated for each size group and the combined size groups. Two size groups were identified: Group 1, subdivided into Subgroup 1.1 and Subgroup 1.2, and Group 2. Each size group presented particular characters which were described, discussed, and compared with relevant literature. The relationship DD-AL was positively allometric for Group 1 and combined size groups, and isometric for Group 2. The results highlight the potential of quantitative analyses to address size-related morphological changes in ophiuroids, and the importance of conducting this type of study to correctly identify species regardless of their size. This is the first study to describe size-related morphological changes of a brittle star from the Eastern Pacific, and the first one focused on a member of Ophiocomidae globally.