Using non-lethal methods for data collection of individuals and participatory monitoring by fishermen, we provide the first empirical evidence of the use of a nursery area by neonate and young-of-the-year cownose rays Rhinoptera bonasus and R. brasiliensis in southeastern Brazil. Two methods were used to collect data: (1) information provided by fishermen (reports, pictures, and videos) and (2) field sampling by researchers. A total of 746 cownose rays were captured; 113 have been identified as R. bonasus, 15 as R. brasiliensis, and 618 were reported by fishermen and could not be identified to the species. Records of newborns were made only in late spring and summer in 2015, 2016, and 2017, which suggests an annual reproductive cycle, with birth in late spring, extending to summer. A repeated use of this area by R. bonasus suggests that it is potentially important to the reproduction of this species. However, R. brasiliensis requires more studies. Small increases in mortality, resulting from increased fishing or other anthropogenic stressors, can have a disproportionately large effect on population viability. Thus, management of areas used during critical stages of the life cycle of rays is crucial to their conservation.
New records of Megalops atlanticus Valenciennes, 1847 in the state of São Paulo, southeastern Brazil, are reported from recreational catches carried out in February 2017. Data collected is the first occurrence of this species in more than 50 years, extending its geographic distribution by about 250 km, from Cananéia, in the south, to Guarujá, on the central coast. Although rarely recorded, M. atlanticus is present off the coast of São Paulo. This possibly represents the southernmost distribution for M. atlanticus in the Southwest Atlantic. Citation: Garrone-Neto D, Rodrigues A (2018) Megalops atlanticus Valenciennes, 1847 (Elopiformes, Megalopidae): new records for the state of São Paulo, with comments on its occurrence in the southeastern coast of Brazil, Southwest Atlantic. Check List 14 (2): 323-327. https://doi.
Despite of the ecological importance of several batoids caught as bycatch, little attention is given to the individual resilience in risk assessments. The report of physical condition is imperative for a realistic understanding of the impacts caused by fishing, as a way to reduce the negative consequences of bycatch and improvement of management protocols. In this context, the present study provides an analysis of injuries observed in nine species of batoids caught by small scale fisheries by adopting a non-lethal approach. Levels of injury were determined according to severity and the relation between fishing time and injury/mortality was assessed. Results showed that injury levels and release condition were strongly influenced by fishing effort and time until release, with fishing effort lower than 110 min related with minor injuries, lower capture mortality rates (10.6%) and better release conditions. Since the frequency of batoids in small scale fisheries as accompanying fauna is high, the cooperation between researchers, fishermen and authorities is essential to reduce the negative consequences of bycatch. Based in the data presented here, we recommend that management plans establish fishing effort times and immediate release in areas of ecological importance for endangered species, thus helping to promote batoids conservation.
Aperfeiçoamento de Pessoal de Nível Superior -Brasil (CAPES) -Finance Code 001 for the Master scholarship.Although interspecific trophic interactions plays a principal role within elasmobranch communal nurseries, little is known over variation in foraging strategies adopted by young-of-year of sympatric species. To test the hypothesis of dietary resource partitioning between batoids within a communal nursery, we investigated two cownose ray species, Rhinoptera bonasus and R. brasiliensis, which occur in heterospecific groups, a strategy predicted to increase survival and foraging success. Using two biochemical tracers, fatty acids (FA) and stable isotopes (δ 15 N and δ 13 C), the combined effects of maternal investment and the formation of heterospecific groups implying competition for, or partitioning of available food resources were investigated. Through univariate and multivariate analyses of biochemical tracers in several tissues (fin clip, muscle, liver, red blood cells; RBC) and plasma, our results revealed significant interspecific differences in tracers between the two species. Total FAs ( P saturated FA, P monounsaturated FA and P polyunsaturated FA) and trophic biomarkers (i.e., docosahexaenoic acid, arachidonic acid, oleic acid and δ 15 N) were the principle tracers responsible for the differences detected. These data revealed that R. brasiliensis was less enriched in physiologically important essential FAs than R. bonasus. Our findings suggest that these congeneric species differ in maternal investment strategy and moderately partition food resources over relatively fine spatial scales within a single nursery habitat to limit competition. These results provide further knowledge on the foraging strategies adopted by batoids in communal nursery areas, information that is required for improving spatial conservation and management planning. K E Y W O R D S elasmobranch, fatty acids, life history strategy, maternal investment, stable isotopes, trophic ecology
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