Temporal and spatial variability in the isotopic composition of sea urchins along Portuguese coast.

Paracentrotus lividus is a sea urchin widely distributed throughout Mediterranean basin and Atlantic coast, highly appreciated for its gonads. It is broadly distributed along the Portuguese coast and its exploitation has potential to grow. Nevertheless, fluctuations on nutritional composition and sensory traits of P. lividus according to each habitat and seasonality are still little understood. Stable isotopes analysis has been recognised as a powerful tool for exploring environmental-ecological-biological processes in aquatic systems. It is also useful to give indications on how to improve available diets for the aquaculture of this species, contributing to a sustainable rearing. Herein, such technique was used to assess temporal and spatial differences in isotopic composition of P. lividus' gonads and intestines and to evaluate its application as a management tool for the identification of the most suitable locations and periods of the year to collect organisms with high quality gonads. Sampling campaigns were carried out between 2019 and 2020 in five rocky shores along the Portuguese coast (Viana do Castelo, Figueira da Foz, Peniche, Sines and Guia). Three rock pools were selected in each shore, and five specimens were collected per pool. The gonadosomatic index (GSI, %) was calculated and carbon and nitrogen elemental and isotopic composition were determined in gonads and intestine using isotope ratio mass spectrometry. Significant spatial and temporal fluctuations were registered among urchins collected along Portuguese coast. Such variations may be associated with latitudinal gradients along the coast and variations of environmental and ecological conditions within each area, especially those affecting algal biomass, on which urchins primarily feed. More research must be pursued to maximise the use of stable isotopes analysis as a management tool for supporting sustainable exploitation of natural stocks or even to contribute to nutritional studies with new diets for sea urchin production that consider the feeding of these animals in the wild.

A Validation Study of the German Version of the Sexual Inhibition/Sexual Excitation Scales-Short Form.

The dual control model of human sexual behavior proposes that sexual responses involve an interaction between sexual excitatory and sexual inhibitory systems. The Sexual Inhibition/Sexual Excitation Scales (SIS/SES; Janssen, Vorst, Finn, & Bancroft, 2002) as well as its short form (SIS/SES-SF; Carpenter, Janssen, Graham, Vorst, & Wicherts, 2011) assess individual propensities to become sexually excited and sexually inhibited. The present study utilized a dataset of 2221 German-speaking adults (n = 1214 women and n = 987 men) to examine the psychometric properties of the German version of the SIS/SES-SF. The results of the confirmatory factor analysis indicated that the three factors suggested in the original version can be generally replicated within the current study. Analyses of measurement invariance for gender revealed that the general three-factor structure as well as factor loadings can be regarded as equal for men and women. However, scalar invariance could not be fully obtained, indicating that the intercepts of some items were different for men and women. Taken together, the results of the presents study provide further evidence for the psychometric properties of the German version of the SIS/SES-SF.