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Triploid Oncorhynchus mykiss is an important economic fish worldwide. Fishing stress can affect its growth and meat quality. This study first explored the effects of fishing stress on fatty acid and amino acid in triploid O. mykiss. Results showed fishing stress significantly reduced the content of docosadienoic acid, Gly, Arg, and DAA (P < 0.05). Targeted lipidomics analysis furthered suggested that some lipid molecules belonging to TG, DG, PC, Cer, ChE, and So were significantly up-regulated; while some lipid molecules belonging to Cer, LPE, LPC, PS, PC, and SM were significantly down-regulated, suggesting an accelerated glycolipid metabolism. Eventually, the glycolipid metabolism-related enzyme activity and gene expressions were examined, and the results indicated that O. mykiss was anti-oxidative stress by affecting relevant glycolipid metabolism signaling pathways and participating in cellular redox homeostasis. Findings of this study provide a theoretical foundation for further investigation into the mechanisms through which fishing stress affects O. mykiss. [Display omitted] • Significant changes in fatty acid and amino acid content of triploid O. mykiss after fishing stress. • Dysregulated lipid molecules were involved in glyceride metabolism and sphingolipid metabolism. • Fishing stress disrupts glycolipid metabolism. [ABSTRACT FROM AUTHOR]

Elasmobranchs are particularly vulnerable to overexploitation and population depletion, especially due to their life‐history traits, such as low reproductive output and slow growth. Given that capture‐induced parturition (abortion or premature birth) is a common consequence of fisheries in elasmobranchs, but still little studied, we investigated how the abortion/premature birth process varies in response to reproductive traits in a freshwater stingray, Potamotrygon amandae. Our results revealed that capture‐induced parturition was affected by reproductive traits, such as litter size (one to seven) and gestation stage. The event occurred faster in pregnant females with high litter size during late pregnancy. Also, as found in other elasmobranchs, litter size was positively correlated with maternal size. These findings indicate that larger pregnant females in late pregnancy are more vulnerable to capture‐induced parturition. This study improves our understanding of the capture‐induced parturition process in stingrays, and provides useful information for management strategies and future recommendations for elasmobranch conservation. [ABSTRACT FROM AUTHOR]

The fate of bycatch species released back into the water is crucial to estimate population status and consequent decisions to implement adequate management measurements for elasmobranchs. The shortnose guitarfish, Zapteryx brevirostris, is an endemic species of the Southwest Atlantic. It is currently listed as 'Vulnerable' both in the International Union for Conservation of Nature and Brazilian red lists. Although this species displays high tolerance to capture and transportation by fishers from the capture site to the fish market, a significant reduction in survival rates is observed during the reproductive period. Thus, the aim of the present study was to examine post‐capture and post‐commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil. Results showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory. Stress plasma markers were also evaluated, to determine the physiological consequences of capture‐induced parturition to pregnant females. Results showed alteration in all markers measured (plasma urea, pH, lactate, phosphorus, and potassium) with values for dead pregnant females being different from non‐pregnant females and those which survived capture and subsequent abortions. The mortality caused by fisheries bycatch may prove difficult to manage, with immediate release and specific handling protocols for pregnant females implemented through environmental education environmental education and fishermen training programs, potential options to maintain adequate maternal survival and recruitment for this species. There is a growing concern about elamobranch overfishing worldwide, as well as an urgent need for the implementation of containment plans for bycatch, representing a very significant volume of annual catches for batoids and sharks. This study provides new information to understand the impact caused by incidental capture in an endemic and threatened guitarfish, suggesting practices to assist with satisfactory management plans for the shortnose guitarfish, Zapteryx brevirostris, especially during their reproductive season. [ABSTRACT FROM AUTHOR]