Biology subjects

Cobo, F.

Publications and source records attributed to Cobo, F..

3 recordsLinked to original sources

bioRxiv2025

Population-specific bycatch risks in two vulnerable anadromous clupeids: insights from otolith microchemistry

Otolith microchemistry analysis revealed that bycatch of European shads--allis shad Alosa alosa (L. 1758) and twaite shad Alosa fallax (Lacepede 1803)-- in western Iberian commercial fisheries removes individuals from a wide array of natal origins, with the most abundant source rivers suffering the heaviest losses. Spatial variation in bycatch risk was evident: specific marine areas exhibited high natal-origin diversity, reflecting complex dispersal. A. alosa showed extensive medium- and long-distance movements-- including rare longitudinal displacements along the Cantabrian slope--and greater natal origin diversity than A. fallax, whose dispersal was largely restricted to middle-distance, latitudinal migrations. In both species, bycatches were dominated by the most abundant continental populations--Mondego and Minho for A. alosa, and Ulla and Minho for A. fallax--suggesting that these rivers function as source populations exporting individuals to sink populations through marine dispersal. Despite their differing dispersal ranges, both species displayed dual resident-dispersive contingents coexisting within the same populations, reflecting an interplay of river proximity, philopatry and resource availability. The stronger philopatry and constrained range of A. fallax imply heightened vulnerability to localized bycatch pressure near natal rivers, whereas A. alosas broader dispersal and higher origin diversity expose multiple populations to risk at a regional scale. These species-specific dispersal capacities and metapopulation structures critically shape bycatch vulnerability. Incorporating natal-origin and dispersal data into transnational, ecosystem-based management--such as targeted temporal or spatial fishing restrictions at mixing hotspots--will be essential to safeguard metapopulation dynamics, mitigate bycatch mortality, and maintain ecological connectivity among European shad populations.

ecology↗

bioRxiv2024

The relationship between gut and nasopharyngeal microbiome composition can predict the severity of COVID-19

Coronavirus disease 2019 (COVID-19) is a respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that displays great variability in clinical phenotype. Many factors have been described to be correlated with its severity, and microbiota could play a key role in the infection, progression, and outcome of the disease. SARS-CoV-2 infection has been associated with nasopharyngeal and gut dysbiosis and higher abundance of opportunistic pathogens. To identify new prognostic markers for the disease, a multicenter prospective observational cohort study was carried out in COVID-19 patients divided into three cohorts based on symptomatology: mild (n=24), moderate (n=51), and severe/critical (n=31). Faecal and nasopharyngeal samples were taken, and the microbiota was analyzed. Linear discriminant analysis identified M. salivarium, P. dentalis, and H. parainfluenzae as biomarkers of severe COVID-19 in nasopharyngeal microbiota, while P. bivia and P. timonensis were defined in faecal microbiota. Additionally, a connection between faecal and nasopharyngeal microbiota was identified, with a significant ratio between P. timonensis (faeces) and P. dentalis and M. salivarium (nasopharyngeal) abundances found in critically ill patients. This ratio could serve as a novel prognostic tool for identifying severe COVID-19 cases.

microbiology↗

bioRxiv2021

Population genetics reveals cryptic lineages and ongoing hybridization in a declining migratory fish species complex

Deciphering the effects of historical and recent demographic processes responsible for the spatial patterns of genetic diversity and structure is a key objective in evolutionary and conservation biology. Using population genetic analyses, we investigated the demographic history, the contemporary genetic diversity and structure, and the occurrence of hybridization and introgression of two species of anadromous fish with contrasting life history strategies and which have undergone recent demographic declines, the allis shad (Alosa alosa) and the twaite shad (Alosa fallax). We genotyped 706 individuals from 20 rivers and 5 sites at sea in Southern Europe at thirteen microsatellite markers. Genetic structure between populations was lower for the nearly semelparous species A. alosa, which disperses greater distances compared to the iteroparous species, A. fallax. Individuals caught at sea were assigned at the river level for A. fallax and at the region level for A. alosa. Using an approximate Bayesian computation framework, we inferred that the most likely long term historical divergence scenario between both species and lineages involved historical separation followed by secondary contact accompanied by strong population size decline. Accordingly, we found evidence for contemporary hybridization and bidirectional introgression due to gene flow between both species and lineages. Moreover, our results support the existence of at least one distinct species in the Mediterrannean sea: A. agone in Golfe du Lion area, and another divergent lineage in Corsica. Overall, our results shed light on the interplay between historical and recent demographic processes and life history strategies in shaping population genetic diversity and structure of closely related species. The recent demographic decline of these species populations and their hybridization should be carefully considered while implementing conservation programs.

evolutionary biology↗