Browsing by Author "Awruch, Cynthia"
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- Cutting-Edge methods in Teleost and Chondrichthyan reproductive biologyPublication . Mechaly, Alejandro S.; Awruch, Cynthia; Cabrita, Elsa; Costas, Benjamín; Fernandes, Jorge M.O.; Gallego, Victor; Hirt-Chabbert, Jorge; Konstantinidis, Ioannis ; Oliveira, Catarina; Ramos Júdez, Sandra; Ramos-Pinto, Lourenço ; Fatsini Fernández, ElviraReproduction is a fundamental biological process for producing offspring and ensuring the continuation of the species. With nearly 35,000 fish species worldwide exhibiting a very diverse range of reproductive systems and strategies, the study of fish reproduction is a significant challenge. Research into various fish reproductive models is driven by their use in human biomedical applications, improving the diversification and sustainability of aquaculture species, and developing strategies for biodiversity conservation. These models must be approached from an animal ethics perspective, considering the welfare of the species under study and applying the 3Rs principle (Replacement, Reduction and Refinement). This principle focusses on replacing animals with alternative methods wherever possible, reducing the number of animals used and refining procedures to minimize suffering. While destructive sampling of wild aquatic species should be minimized, the need remains to provide information on reproduction as an important parameter for delineating management and conservation programs. One of the practices that helps reduce and replace the use of animal testing is the scientific study of individuals obtained through bycatch. This is the case for some chondrichthyans, and endangered fish species included in conservation programs. Regarding fish species that are kept under human care (commonly called captivity), studies on reproduction are essential to improve well-being and increase production of farmed species. Research on fish reproduction requires expanding basic knowledge of broodstock management tools, such as gamete quality assessment, reproductive behavior studies, the use of hormone therapies to stimulate reproduction, and the development of non-lethal or less invasive methods using body fluids (e.g., mucus, seminal plasma, blood plasma, or urine) to study reproductive status, as well as novel markers from state-of-the-art omics research. This review describes a multidisciplinary approach that includes the aforementioned reproductive management tools, indicators of welfare, and next-generation sequencing techniques using samples collected by minimally invasive methods.
- Genetic diversity in the American elephantfish (Chimaeriformes: Callorhinchus callorynchus) and among its congenersPublication . Erk, Cornelia Pia; Concha, Francisco J.; Awruch, Cynthia; Finucci, Brittany; Cristiani, Franco; Guzmán‐Castellanos, Ana B.; Silva, Charlene da; Veríssimo, AnaUnderstanding genetic population structure and connectivity is essential for effective species-specific management and conservation strategies. The American elephantfish Callorhinchus callorynchus is targeted and retained as incidental catch in commercial and recreational fisheries in Chile and Argentina. Its wide-ranging distribution across southern South America may require transnational co-operation to ensure sustainable use, but its current population structure is not known. In this work, we analysed the levels of genetic diversity and differentiation within C. callorynchus in South America using two mitochondrial markers, the control region (CR) and the cytochrome oxidase subunit I gene (CO1). Moreover, we assessed levels of genetic diversity within, and divergence among, the three extant callorhinchids (genus Callorhinchus), a group that exhibits allopatric geographical distributions in the southern hemisphere. Overall, sequence analyses of the mitochondrial CR and the CO1 revealed extremely low levels of sequence variation both within and among Callorhinchus species. Genetic homogeneity was found throughout the range of C. callorynchus coupled to low-frequency haplotype sharing across spatially distant locations in Chile and Argentina, suggesting gene flow along the South American coast. Moreover, our analyses supported a scenario of recent population expansion of the species in South America. Given the absence of dispersive eggs or juvenile stages in chondrichthyans, gene flow is mainly mediated by actively swimming adults. Based on the available data, gene flow in callorhinchids appears to occur along continuous coastal regions, with deep oceanic waters serving as strong barriers. Findings here provide an important baseline for future research on dispersal and gene flow in holocephalans.