Otolith shape and elemental signatures provide insights into the connectivity of euryhaline chelon labrosus inhabiting two close estuaries with different burdens of xenoestrogens in the southern bay of biscay

Intersex gonads have been observed in thicklip grey mullet Chelon labrosus, inhabiting estuaries with high burdens of xenoestrogens in the Southeast Bay of Biscay, but knowledge of population connectivity among estuaries is lacking for this euryhaline fish species. This study investigates the population structure of C. labrosus using otolith shape and elemental signatures of 60 adults (overall length ~ 38 cm) from two estuaries 21 nautic miles apart, one with a high incidence of intersex condition (Gernika), and the other one pristine (Plentzia). Otolith shape analyses were performed using elliptical Fourier descriptors, while elemental signatures of whole sagittae were obtained by inductively coupled plasma mass spectrophotometry. Univariate and multivariate statistics were applied to determine if otolith signatures show patterns of homogeneity between estuaries. The data indicated significant differences in the otolith shape and elemental composition between mullets of Gernika and Plentzia. Elemental differences were mainly driven by Sr, Li (both higher in Plentzia) and Ba (higher in Gernika). The 98% re-classification success rate obtained from stepwise linear discriminant function analysis suggests that Gernika and Plentzia individuals form separated population units. The limited connectivity between these two close estuaries would indicate a different life history of exposure to chemicals, which might explain the high prevalence of intersex condition in Gernika and its absence in Plenztia.info:eu-repo/semantics/publishedVersio

Lack of genetic structure in euryhaline Chelon labrosus from the estuaries under anthropic pressure in the Southern Bay of Biscay to the coastal waters of the Mediterranean Sea

Over the last decade, xenoestrogenic effects have been reported in populations of thicklip grey mullet Chelon labrosus from contaminated estuaries in the Bay of Biscay, resulting in intersex condition. To understand the level of gene flow in individuals of different Basque estuaries microsatellite markers were used to evaluate the population structure and connectivity of C. labrosus from estuaries of the Basque coast. 46 microsatellites were tested and 10 validated for the analysis of 204 individuals collected from 5 selected Basque estuaries and 2 outgroups in the Bay of Cadiz and Thermaic Gulf. The polymorphic microsatellites revealed 74 total alleles, 2–19 alleles per locus. The mean observed heterozygosity (0.49 ± 0.02) was lower than the expected one (0.53 ± 0.01). There was no evidence of genetic differentiation (FST = 0.0098, P = 0.0000) among individuals or sites. Bayesian clustering analysis revealed a single population in all sampled locations. The results of this study indicate widespread genetic homogeneity and panmixia of C. labrosus across the current sampling areas spanning the Atlantic and Mediterranean basins. The hypothesis of panmixia could therefore be well supported so individuals inhabiting estuaries with high prevalence of intersex condition should be considered as members of the same single genetic group as those inhabiting adjacent estuaries without incidence of xenoestrogenicity.This work was funded by the Spanish Ministry of Science. Innovation and Universities and EU-FEDER/ERDF (BORN2bEGG PGC2018-101442-B-I00) and the Basque Government (Grants to consolidated research groups IT1302-19 and IT1743-22). A.N. is a recipient of a pre-doctoral grant PIF17/172 from the University of the Basque Country (UPV/EHU). Authors wish to thank the help of two anonymous reviewers for significantly helping in better focusing the aim of the present work

Use of otolith shape and elemental signatures to infer the population structure of the Thicklip Grey Mullet Chelon labrosus in the Southern Bay of Biscay

Xenoestrogenic effects have been reported in thicklip grey mullet, Chelon labrosus, used as pollution sentinel organisms in estuaries in the Southeast Bay of Biscay with intersex gonads described in populations from some contaminated estuaries. Despite evidence of reproductive stress in this catadromous fish species, knowledge of mullet reproductive movements and connectivity between estuaries is lacking. This study investigates the population structure of C. labrosus using otolith shape and elemental signatures of 60 adult individuals collected from two estuaries found in the Southeast Bay of Biscay (Gernika and Plentzia). All samples were collected in June–July 2020. Otolith shape analysis was determined using elliptical Fourier descriptors, while elemental signatures (Sr:Ca, Li:Ca, Mg:Ca, Mn:Ca, Co:Ca, Ni:Ca, Cu:Ca and Ba:Ca) of whole sagittae were determined by inductively coupled plasma mass spectrophotometry. Both natural tags were analyzed with univariate and multivariate statistics to determine whether these signatures are geographically distinct and can be used to assess the degree of separation between individuals. The data showed significant differences in the otolith shape and elemental analyses, with canonical analysis of principal coordinates plots identifying two different groups, each one belonging to each estuary of origin. Differences in whole otolith elemental signatures between locations were driven by Sr:Ca, Li:Ca, and Ba:Ca. Sr:Ca and Li:Ca ratios were higher in Plentzia than in Gernika, while Ba:Ca was higher in Gernika. The high re-classification success rate using both tools obtained from stepwise linear discriminant function analysis supports these findings and suggests that Gernika and Plentzia individuals passed enough time in separated water compartments and should be regarded as two different population units. This could suggest that the intersex condition in mullets from Gernika is due to life-long exposure to xenoestrogens after homing during early larval development in that estuary, without migrations to other estuaries.info:eu-repo/semantics/publishedVersio

Guest house supervisors’ meaning cognition and its influence on job satisfaction in the context of Mombasa County, Kenya

The alignment between an employee’s work role and his/her beliefs, attitudes, values and behaviours (meaning) are critical human resource issues in guest house operations. This is because, compared to classified hotels, guest houses have a larger percentage of untrained personnel. For those with hospitality training, they are usually recruited as supervisors. This notwithstanding, the owners of guest houses tend to dictate and control almost all the operations, thus lowering employee empowerment; a major source of job satisfaction. This study sought to determine the influence of meaning, a dimension of psychological empowerment, on job satisfaction of guest house supervisors. A descriptive survey study design, focusing on the seventy-six registered guest houses in Mombasa County was used. The study utilized census, where all the supervisors in all the registered guest houses in Mombasa County were included. Primary data was collected through a semi-structured questionnaire. Pre-testing was done in three guest houses and the remaining seventy-three were included in the study. Data was analysed by means, percentages and standard deviations. Pearson correlation coefficient and linear regression were used to establish the relationship between the study variables. Findings revealed that there existed a positive and significant influence (p< 0.05) of meaning on job satisfaction (r= 0.765). This study could well be of critical importance to guest house entrepreneurs and managers who would be able to formulate and implement empowerment strategies for their supervisors and other staff. In addition, it will be helpful to organizations such as the Kenya National Chamber of Commerce and Industry, the Federation of Kenyan Employers, the Kenya Association of Hotelkeepers and Caterers and Pubs Entertainment and Restaurant Association of Kenya, in sensitizing their various members on the importance of aligning employee’s work roles to their beliefs, attitudes, values and behaviours

Apoptosis and autophagy-related gene transcription during ovarian follicular atresia in European hake (Merluccius merluccius).

Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of female fish when environmental conditions are unfavourable and at the expense of fecundity. This study investigated the transcription levels of apoptosis and autophagy-related genes during atresia in the European hake that can show episodes of increased follicular atresia throughout the reproductive cycle. 169 female individuals were collected from the Bay of Biscay, and the ovaries were analysed using histological and molecular methods. Different levels of atresia were histologically detected in 73.7% of the ovaries analysed and the TUNEL assay identified apoptotic nuclei in follicles from both previtellogenic and vitellogenic stages. Transcripts of beclin-1 and ptenb were up-regulated in the ovaries containing atretic follicles, whereas p53, caspase-3, cathepsin D and dapk1 were up-regulated only in ovaries presenting vitellogenic atretic follicles. Our results indicate different implications of apoptotic vs autophagic processes leading to atresia during oocyte development, vitellogenesis being the moment of maximal apoptotic and autophagic activity in atretic hakes. The analysed genes could provide early warning biomarkers to identify follicular atresia in fish and evaluate fecundity in fish stocks.This work was funded by the Spanish Ministry of Science, Innovation and Universities (ATREoVO AGL2015-63936-R and BORN2bEGG PGC2018-101442-B-I00) and by the Basque Government (Grant to consolidated research groups IT1302-19). A.N. is a recipient of a pre-doctoral grant from the University of the Basque Country (UPV/EHU). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript