Browsing by Author "Ferreira, Carlos E. L."
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- Abundance, diet, foraging and nutritional condition of the banded butterflyfish (Chaetodon striatus) along the western AtlanticPublication . Liedke, Ana M. R.; Barneche, Diego R.; Ferreira, Carlos E. L.; Segal, Barbara; Nunes, Lucas T.; Burigo, Ana P.; Carvalho, Jose A.; Buck, Sonia; Bonaldo, Roberta M.; Floeter, Sergio R.The feeding behaviour and diet plasticity of a given species are usually shaped by the relationship between species physiology and the quality and availability of resources in the environment. As such, some species may achieve wide geographical distributions by utilizing multiple resources at different sites within their ranges. We studied the distribution and feeding of Chaetodon striatus, the most widespread butterflyfish in the Atlantic, by assessing its density and foraging rates in eight sites enclosing 44 degrees of latitude. We also evaluated the relationship between fish density and foraging rates with nutritional condition and diet across study sites, and the gut length relative to body size. Density and foraging rates did not differ among studied sites. In 169 stomachs analysed, we found 52 different items (12-23 per site). Polychaeta and Cnidaria were the most important items in seven study sites. Therefore, C. striatus may be considered as a non-coral generalist feeder, as it feeds on a wide variety of items and substrata along the studied range, with no consistent selectivity pattern for foraging substratum across sites. Individuals from all sites but Salvador (NE Brazil) had similar RNA/DNA ratios, suggesting that C. striatus nutritional condition is similar along its extensive distribution. Our findings highlight the importance of assessing different sites within the distribution range of generalist butterflyfishes, and different variables, to a better comprehension of the feeding ecology of these species.
- Unlocking the history of a trans‐Atlantic invader: did the human slave trade impact Brown mussel dispersal?Publication . Calazans, Sávio H.; Lourenço, Carla R.; Nicastro, Katy; Tagliaro, Claudia H.; Zardi, Gerardo I.; Ferreira, Carlos E. L.; C. Fernandes, Flavio; Silva, Edson P.; Hoffman, Eric A.; Floeter, SergioAim Brown mussels exhibit a trans-Atlantic distribution putatively caused by either native dispersal or artificial gene flow, likely in concert with the transport of enslaved people from Africa. Evolutionary history and demographic models of this widespread species may clarify how the present-day distribution was impacted by natural versus artificial dispersal. Particularly, dating the timing of the South American/African split may determine whether the human slave trade likely impacted the contemporary distribution of brown mussels. Location Coastal Brazil, Morocco, South Africa, and Mozambique. Taxon Perna perna (Linnaeus 1758). Methods We genotyped a total of 644 samples from 18 populations at 10 microsatellite loci. We estimated genetic structure with clustering algorithms in STRUCTURE and GENETIX. We estimated genetic distances by characterizing patterns of pair-wise F-ST using the program FSTAT, evaluating differences among and between regions via AMOVA, and testing isolation by distance in IBDWS. To estimate and date the most likely pathway by which P. perna crossed the Atlantic Ocean we used Bayesian factors from thermodynamically heated coalescent simulations in the program MIGRATE-n. Results We found no general pattern of reduced or elevated levels of genetic diversity within any region across site or locus. We identified four genetic clusters: East South Africa (ESA), West South Africa (WSA), Brazil (BR) and North Africa (MO); F-ST ranged from 0.06 to 0.11 among regions and exhibited a significant pattern of isolation by distance. Migration models indicated that P. perna dispersed from WSA to MO and from there to BR of approximately 2,000 years. Main conclusions Multiple lines of evidence suggest the Brazilian populations of P. perna have been a long-standing native population, originating from northern Africa and are unlikely a consequence of the African slave trade. Although, human introduction cannot be ruled out South American P. perna populations exhibited genetic characteristics indicative of a divergent, isolated and established population, featuring the genetic signature expected for a native population.