Dr. Urzua-Osorio, Angel

Environmental variables are key drivers of reproductive traits in marine organisms, which can have significant economic consequences in commercial species. Pleuroncodes monodon is an important resource of the industrial fisheries’ fleet of the Humboldt Current System. This species is subject to seasonal variations in pivotal variables such as temperature and food availability, as well as, climatic events. We herein analyse the variations in reproductive parameters and in the eggs’ biochemical profiles in relation to environmental conditions. Differences in all studied parameters were found between 2014 and 2015. In 2015, fecundity (measured as total number of eggs) and protein content were higher than 2014, but lipid content showed the opposite pattern. Seasonal and interannual variations were also observed in the energy content per egg; whilst the brood energy content did not show seasonal or interannual variation. This information is of utmost importance for integrative management of this commercial good as the data measures dynamic variations in the species populations. Currently, this squat lobster is overexploit and so far, no seasonal nor interannual variations have been considered in its management plan. The present study provides evidences that the female lobsters need different management strategies to maintain sustainable fisheries of Concepcion, Chile.

Pleuroncodes monodon, an important fishery resource and key species in the Humboldt Current Large Marine ecosystem, has a prolonged reproductive period from winter until end of summer, and during this time females incubating their embryos are exposed to seasonal variation in food availability and in temperature. Additionally, in order to ensure successful reproduction and survival of embryos, changes occur in the main internal reserves and/or sources of energy of P. monodon. The aim of this study was to determine the extent of seasonal variation (winter vs summer) in the lipid content and fatty acid composition of ovigerous females and their embryos. The results show that a higher percentage of saturated and polyunsaturated fatty acids are found in females in winter. Similarly, the composition of fatty acids in embryos found here indicates that winter embryos have more saturated fatty acids and essential fatty acids (C18:2n6cis, C18:3n6 and C22:6n3) than do summer embryos. According to PCA analysis of fatty acid profile, samples from summer may be distinguished into two isolated groups with conspicuous variations in fatty acids profile of embryo and hepatopancreas. While in winter, the opposite pattern occurs in the fatty acid profile of embryo and hepatopancreas. These variations may be related to relevant physiological processes (reproduction and growth) and of their ontogeny (development and survival of offspring). Seasonal variation in the lipid content and composition of fatty acids of P. monodon could directly impact this species’ reproduction and survival and subsequently could have consequences on the food web and fishery exploitation.