Browsing by Author "Floeter, Sergio R."
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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.
- Ecological traits influencing range expansion across large oceanic dispersal barriers: insights from tropical Atlantic reef fishesPublication . Luiz, Osmar J.; Madin, Joshua S.; Ross Robertson, D.; Rocha, Luiz A.; Wirtz, Peter; Floeter, Sergio R.How do biogeographically different provinces arise in response to oceanic barriers to dispersal? Here, we analyse how traits related to the pelagic dispersal and adult biology of 985 tropical reef fish species correlate with their establishing populations on both sides of two Atlantic marine barriers: the Mid-Atlantic Barrier (MAB) and the Amazon-Orinoco Plume (AOP). Generalized linear mixed-effects models indicate that predictors for successful barrier crossing are the ability to raft with flotsam for the deep-water MAB, non-reef habitat usage for the freshwater and sediment-rich AOP, and large adult-size and large latitudinal-range for both barriers. Variation in larval-development mode, often thought to be broadly related to larval-dispersal potential, is not a significant predictor in either case. Many more species of greater taxonomic diversity cross the AOP than the MAB. Rafters readily cross both barriers but represent a much smaller proportion of AOP crossers than MAB crossers. Successful establishment after crossing both barriers may be facilitated by broad environmental tolerance associated with large body size and wide latitudinal-range. These results highlight the need to look beyond larval-dispersal potential and assess adult-biology traits when assessing determinants of successful movements across marine barriers.
- Restructuring of the ‘Macaronesia’ biogeographic unit: a marine multi-taxon biogeographical approachPublication . Freitas, Rui; Romeiras, Maria; Silva, Luís; Cordeiro, Ricardo; Madeira, Patrícia; González, José Antonio; Wirtz, Peter; Falcón, Jesús M.; Brito, Alberto; Floeter, Sergio R.; Afonso, Pedro; Porteiro, Filipe; Viera-Rodríguez, María Ascensión; Neto, Ana Isabel; Haroun, Ricardo; Farminhão, João N. M.; Rebelo, Ana Cristina; Baptista, Lara; Melo, Carlos S.; Martínez, Alejandro; Núñez, Jorge; Berning, Björn; Johnson, Markes E.; Ávila, Sérgio P.The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term "Macaronesia". This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islands.