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A single Pomacanthus maculosus was filmed during a scuba diving survey on a rocky reef from southern Brazil. The body shape and coloration pattern confirmed the species identification. The biological and ecological characteristics of P. maculosus and the long distance of Brazil from its original distribution strongly suggest of an anthropogenic pathway of dispersion. [ABSTRACT FROM AUTHOR]

Aim Sea-level changes and coastal geomorphology (extension of continental shelves) have affected the pattern of diversification of brackish/freshwater fish populations due to the confluence of basins/estuaries during low sea-level periods (opportunity) and isolation during high sea-level periods. It is hypothesized that populations from estuaries in extensive continental shelves, which have greater potential for confluence, should have more opportunities for gene exchange than those in narrow continental shelves. To test this, we assessed the distribution of the genetic diversity and the patterns of diversification of the estuarine silverside, Atherinella brasiliensis, from the Brazilian coast. Location Eight estuaries along the southern and north-eastern portions of the Brazilian coast. Materials and methods Sequences of the mitochondrial control region (D-loop) and the cytochrome B were used to assess the distribution of genetic diversity, and these mitochondrial fragments and two nuclear introns were used to assess the patterns of diversification of A. brasiliensis. The palaeochannels that were exposed along the Brazilian coast during the Last Glacial Maximum were reconstructed using bathymetry data and the GIS method. Results The populations of A. brasiliensis from the estuaries of the north-eastern Brazilian coast (narrower and shallower continental shelf) showed higher levels of genetic differentiation and larger (more haplotypes) endemic lineages than the populations in the southern coast (broader and deeper continental shelf). Furthermore, south coast lineages showed more evidence of genetic exchange among populations, which have resulted in a reticulated relationship between lineages and estuaries. The reconstruction of palaeochannels revealed more connections among southern than north-eastern basins. Main conclusions Our results support the hypothesis that continental shelf extension and sea-level changes have influenced the diversification of A. brasiliensis. By extension, they also support the hypothesis of diversification by taxon pulse, which makes predictions based on the opportunities for expansion during periods of low sea level and the width of the continental shelf. We suggest this as a model for the genetic diversification and distribution of estuarine species along the Brazilian coast and other regions of the world. [ABSTRACT FROM AUTHOR]

The consistency and environmental correlates of habitat- and season-related differences among shallow-water fish assemblages inhabiting estuarine beaches (EB) and tidal flats (TF) were examined in the subtropical Paranaguá estuary, which borders a World Heritage listed area. Assemblages were diurnally sampled each month (May 2003–March 2004) using small-meshed beach seines. Forty-six and 49 species were captured at EB (24 families) and TF (23 families), with most individuals at the latter (66 and 54% by number and biomass). Resident fishes accounted for 74% of individuals, but only 31% of all species. Most species were juvenile marine transients, but occurred sporadically and in low numbers. Three residents ( Sphoeroides testudineus , Atherinella brasiliensis and Sphoeroides greeleyi ) dominated assemblages and contributed the most to the index of relative importance of each habitat. Habitat-related differences in assemblages and key population parameters were complex and generally depended on the month sampled rather than water salinity or temperature (owing to comparable temporal variability). Ocean proximity was probably the cause of some differences, with more recruits of marine species early in the wet season at EB, but later at TF. Nevertheless, some resident gobiids and paralichthyids displayed habitat partitioning, possibly related to sediment preferences. There were strong seasonal differences in assemblages, primarily due to more juveniles of resident and transient species during the wet and possibly reflecting more optimal conditions for the young-of-the-year survival due to increased primary and secondary productivity. Environmental correlates of salinity and temperature with assemblage parameters were generally weak, but increasing water temperature prior to the wet season may be a key driver for reproduction, so that larvae are delivered during the wet season. The shallow, low-energy sandy beaches and tidal flats are used by a large diversity of fish, and consequently need to be considered in conservation and biodiversity estuary management plans. [ABSTRACT FROM AUTHOR]

The global panorama of biodiversity loss has motivated international agreements to enhance the protection of the oceans. Given the conflicting interests arising from multiple uses of seascapes and finite funds for conservation, developing cost-effective strategies for marine biodiversity conservation is crucial to support decision making. Here, we identified sites in Brazilian waters that would maximize species representation and avoid potential conflicts with relevant economic activities. We compared conservation benefits provided by three conservation-planning scenarios that incorporated the distribution of 750 marine vertebrate species, while considering established marine protected areas (MPAs) and blocks concessioned for the oil and gas industry. The results showed that a MPA network encompassing 10% of the study area with high conservation priority would cover between 85.8 and 86.5% of species distributions, on average. We found that incorporating existing MPAs and areas concessioned for oil and gas exploitation in the prioritization process caused only a small loss in representation of near-threatened and threatened species. Our results highlight, therefore, that it is possible to reconcile current offshore oil and gas production with the expansion of the national MPA network, without significant losses in species' representation. These results represent a preliminary assessment of spatial priorities for conservation of marine vertebrates in Brazilian waters. They can be used to prompt a dialog with social actors, in order to expand the national MPA system. [ABSTRACT FROM AUTHOR]

While the number of species is a key indicator of ecological assemblages, spatial conservation priorities solely identified from species richness are not necessarily efficient to protect other important biological assets. Hence, the results of spatial prioritization analysis would be greatly enhanced if richness were used in association to complementary biodiversity measures. In this study, geographic patterns in estuarine fish species rarity (i.e. the average range size in the study area), endemism and richness, were mapped and integrated to identify regions important for biodiversity conservation along the Brazilian coast. Furthermore, we analyzed the effectiveness of the national system of protected areas to represent these regions. Analyses were performed on presence/absence data of 412 fish species in 0.25° latitudinal bands covering the entire Brazilian biogeographical province. Species richness, rarity and endemism patterns differed and strongly reflected biogeographical limits and regions. However, among the existing 154 latitudinal bands, 48 were recognized as conservation priorities by concomitantly harboring high estuarine fish species richness and assemblages of geographically rare species. Priority areas identified for all estuarine fish species largely differed from those identified for Brazilian endemics. Moreover, there was no significant correlation between the different aspects of the fish assemblages considered (i.e. species richness, endemism or rarity), suggesting that designating reserves based on a single variable may lead to large gaps in the overall protection of biodiversity. Our results further revealed that the existing system of protected areas is insufficient for representing the priority bands we identified. This highlights the urgent need for expanding the national network of protected areas to maintain estuarine ecosystems with high conservation value. [ABSTRACT FROM AUTHOR]

Abstract: As part of attempts to improve and promote acceptance of the Nordmøre-grid in a Brazilian artisanal penaeid canoe-trawl fishery, the effects of bar spaces on the catches of key teleosts and crustaceans were investigated. Compared to a traditional codend, three Nordmøre-grids comprising 24-, 20- and 17-mm bar spaces, respectively, significantly and incrementally reduced the total weight of unwanted brachyurids (by 75, 95 and 97%), without affecting the catches of targeted seabob shrimp (Xiphopenaeus kroyeri). The various grids had few significant impacts on the catches of any teleosts; attributed to their small sizes and species-specific differences in behavioural responses. The results confirm the utility of the Nordmøre-grid for addressing a key bycatch concern among local fishers, and provide insight into ongoing development of appropriate modifications to improve selectivity in this, and other regional fisheries. [Copyright &y& Elsevier]