Spatial and temporal distribution of fish in Palmas bay, Ubatuba, Brazil

The aim of this study was to analyze the distribution and abundance of the fish fauna of Palmas bay on Anchieta Island in southeastern Brazil. Specimens were caught in the summer and winter of 1992, using an otter trawl at three locations in the bay. The specimens were caught in both the nighttime and daytime. Data on the water temperature and salinity were recorded for the characterization of the predominant water mass in the region, and sediment samples were taken for granulometric analysis. A total of 7 656 specimens (79 species), with a total weight of approximately 300 kg, were recorded. The most abundant species were Eucinostomus argenteus, Ctenosciaena gracilicirrhus, Haemulon steindachneri, Eucinostomus gula and Diapterus rhombeus, which together accounted for more than 73% of the sample. In general, the ecological indices showed no differences in the composition of species for the abiotic variables analyzed. The multivariate analysis showed that the variations in the distribution of the fish fauna were mainly associated with intra-annual differences in temperature and salinity, resulting from the presence of South Atlantic Central Water (SACW) in the area during the summer. The analysis also showed an association with the type of bottom and a lesser association with respect to the night/day periods.

Merluccius hubbsi (Teleostei: Merlucciidae): stock identification based on reproductive biology in the south-southeast brazilian region

The Argentine hake, Merluccius hubbsi, a demersal-pelagic species found from Rio de Janeiro, Brazil to the Tierra del Fuego, Argentina, has become an important target of the Brazilian bottom-trawler fleet since 2001. Earlier studies focusing on the species have suggested that more than one stock might occur off the Brazilian coast, in accordance with environmental features. In order to evaluate this hypothesis, fish were collected from four different areas in the Brazilian waters in which the hake is distributed, during the summers and winters of 1996-2001 and 2004, the females being used to analyze and compare spatial-temporal variations in ovarian maturation. Gonad indexes were also applied for the same purpose. Results indicate a north-south spawning gradient occurring as from summer at around 21°S to winter near 34°S, leading to the identification of two distinct stocks: one located between 21°S and 29°S (Southeastern stock) and the other between 29°S and 34°S (Southern stock), this latter shared with Uruguay and Argentina. Brazilian stocks present clear signs of overexploitation, the situation calling for an urgent solution.

Occurrence, distribution and abundance of Halobates micans Eschscholtz, 1822 (Heteroptera, Gerridae) along the southeastern Brazilian coast

Data collected during an oceanographic cruise along the southeastern Brazilian coast from Cape Frio (22° 58' S) and Paraná (27° 50' S) in March 1982 showed that the marine insect Halobates micans occurred along the Southeastern Brazilian Bight, but in lower abundance in low-temperature areas due to the intrusion and upwelling of South Atlantic Central Water, and in low-salinity areas in Coastal Water. Insect capture was higher at night and in the oligotrophic Tropical Water. The number of nymphs and adult females was higher, probably because of an active breeding season during the austral summer. Adult sex ratio was 1.3:1.0 (F:M). Floating gas vesicles of benthic Sargassum spp. and petroleum lumps were used by females for egg-laying.

Ecological aspects of the surf-zone ichthyofauna of Itamambuca Beach, Ubatuba, SP

Sandy beaches are among the most extensive environments in Brazil and are generally threatened by disorderly urban growth due to their location along the coast, where human populations tend to concentrate. This is especially true in southeastern Brazil, where the largest urban areas are located. Thus, better knowledge regarding these natural resources is of considerable importance. The surf zone of sandy beaches is inhabited by a number of fish species, including juveniles seeking both food and shelter from predators. An ecological survey was conducted in the surf zone of Itamambuca beach in the city of Ubatuba, São Paulo State, Brazil, in order to evaluate the composition, structure and dynamics of the fish fauna using community descriptors. Diurnal and nocturnal samples were taken with a beach seine at five oceanographic stations over a 12-month period. Water temperature and salinity were also recorded. A total of 2,147 individuals representing 34 species and 18 families were sampled. The main variation in fish fauna was detected on the diel level, followed by a spatial repartition possibly related to salinity. Seasonal variation was also observed. The five most important species in the overall context were Atherinella brasiliensis, Eucinostomus melanopterus, Mugil sp., Trachinotus goodei and Atherinella blackburni.

Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.

Epilithic community development on artificial reefs deployed along a cross-shelf environmental gradient off Paraná state, southern Brazil

Concrete modules were deployed on the bottom of the 11, 18 and 30 meters isobaths along a cross-shelf hydrographic gradient off Paraná State, Southern Brazil, with the purpose of studying the colonization of sessile epilithic macroinvertebrates on artificial surfaces. After one year of submersion a total of 63 species of epilithic organisms were identified, dominated by Ostrea puelchana, Chthamalus bisinuatus, Balanus cf spongicola, Astrangia cf rathbuni, Didemnum spp, poryphers and bryozoans. Diversity index and percent cover at reef stations placed at 11, 18 and 30 meters isobaths were respectively 2.28 and 66.7%, 2.79 and 96.6% and 1.66 and 77.4%. Differences of general community structure among the three assemblages were not clearly related to the general environmental conditions at the bottom layers near the reef stations. Turbidity and larval abundance are discussed as important factors affecting colonization processes. Results indicate that depths between 15-20 meters are more suitable for the implementation of large scale artificial reef systems in the inner shelf off Paraná and, possibly, throughout the inner shelves off southern Brazil with similar hydrographic conditions.

Brazilian offshore wave climate based on NWW3 reanalysis

This paper provides a description of the wave climate off the Brazilian coast based on an eleven-year time series (Jan/1997-Dec/2007) obtained from the NWW3 operational model hindcast reanalysis. Information about wave climate in Brazilian waters is very scarce and mainly based on occasional short-term observations, the present analysis being the first covering such temporal and spatial scales. To define the wave climate, six sectors were defined and analyzed along the Brazilian shelf-break: South (W1), Southeast (W2), Central (W3), East (W4), Northeast (W5) and North (W6). W1, W2 and W3 wave regimes are determined by the South Atlantic High (SAH) and the passage of synoptic cold fronts; W4, W5 and W6 are controlled by the Intertropical Convergence Zone (ITCZ) and its meridional oscillation. The most energetic waves are from the S, generated by the strong winds associated to the passage of cold fronts, which mainly affect the southern region. Wave power presents a decrease in energy levels from south to north, with its annual variation showing that the winter months are the most energetic in W1 to W4, while in W5 and W6 the most energetic conditions occur during the austral summer. The information presented here provides boundary conditions for studies related to coastal processes, fundamental for a better understanding of the Brazilian coastal zone.

Anthropogenic influences in a lagoonal environment: a multiproxy approach at the valo grande mouth, Cananéia-Iguape system (SE Brazil)

The Cananéia-Iguape system, SE Brazil, consists of a complex of lagoonal channels, located in a United Nations Educational, Scientific and Cultural Organization (UNESCO) Biosphere Reserve. Nevertheless, important environmental changes have occurred in approximately the last 150 yrs due to the opening of an artificial channel, the Valo Grande, connecting the Ribeira de Iguape River to the lagoonal system. Our objective is to assess the historical record of the uppermost layers of the sedimentary column of the lagoonal system in order to determine the history of environmental changes caused by the opening of the artificial channel. In this sense, an integrated geochemical-faunal approach is used. The environmental changes led significant modifications in salinity, in changes of the depositional patterns of sediments and foraminiferal assemblages (including periods of defaunation), and, more drastically, in the input of heavy metals to the coastal environment. The concentrations Pb in the core analyzed here were up to two times higher than the values measured in contaminated sediments from the Santos estuary, the most industrialized coastal zone in Brazil.

Ophionereis reticulata (Echinodermata, Ophiuroidea)

This study compared the arm regeneration frequencies in two different populations of Ophionereis reticulata (Say, 1825) in São Sebastião, Southeast Brazil and observed arm regeneration between age classes (juvenile and adults) and sexes (male and female). From the 1,170 individuals sampled, 1,089 (92.2%) showed signs of arm regeneration. The relative frequencies of regenerating arms in the two areas were not different (Baleeiro Isthmus: 91.3% and Grande Beach: 99.5%). Both areas also presented similar values for the number of arms regenerating/individual and in the frequency of regenerating individuals. The major part of the regenerating scars was concentrated in the distal portion of the arm. Sub-lethal predation is most likely the cause to the high rates of arm regeneration in O. reticulata. There was no significant differences in the regeneration rates between females (3.57 ± 1.36 arms regenerating/individual) and males (3.47 ± 1.42).

A new species of Trichogenes from the rio Itapemirim drainage, southeastern Brazil, with comments on the monophyly of the genus (Siluriformes: Trichomycteridae)

A new species of the formerly monotypic genus Trichogenes is described from a high-altitude stream of the rio Itapemirim system, an isolated Atlantic drainage in the State of Espírito Santo, southeastern Brazil. Trichogenes claviger, new species, differs from all other trichomycterids by the sexually dimorphic posterior process of the opercle, much elongated in males; the terminal mouth; the deeply bifurcated anterior neural spines and the presence of a large anterodorsal claw-like process on the neural arches of the anterior four free vertebrae. The new species also differs from its only congener, T. longipinnis, by a number of additional traits, including the the lack of branched anal-fin rays in specimens of any size; the broader than long posterior nostril; the deeper head (head depth 72.9-86.6% HL); the presence of a fine dark line along the base of the anal fin; the lack of dark spots on cheeks; the shape of the interopercle; the presence of odontodes on a bony expansion on the posterodorsal margin of the interopercle; the fewer vertebrae (35); the absence of an antorbital; and the fewer pleural ribs (eight). Small juveniles of the new species are also strikingly different from those of all other Trichomycteridae, including T. longipinnis, having a very large lateral eye, an upturned mouth, and compressed head. Trichogenes claviger occurs in shaded sectors of a blackwater sluggish stream with sandy substrate and patchy accumulations of vegetable debris, a habitat markedly different from the rocky torrential environment known for T. longipinnis. A comparison of the internal anatomy of the two species provides the basis for a hypothesis of a monophyletic Trichogenes. Data from the new species further support a sister-group relationship between Trichogeninae and Copionodontinae, as well as the position of that clade as sister group to all remaining Trichomycteridae.

Redescription of Hanleya brachyplax (Polyplacophora, Hanleyidae) from the south-southeastern Brazilian coast

Hanleya brachyplax Simone & Jardim in Rios, 2009 is described in detail. The species occurs off the southeastern and south coast of Brazil (São Paulo and Santa Catarina states) in depths from 250 to 408 m. It differs from its congeners in having uniform white valves; wide intermediate valves; the tail valve with straight profile in the antemucronal area, and a concave postmucronal surface; and a cream-colored girdle, covered by non-articulated spines. An anatomical investigation was also performed, showing the main muscle groups; the presence of gills in the posterior third of the pallial groove; auricle with six orifices; a very flat kidney, restricted to the posterior half of the animal; and a simple esophageal region. The odontophore has a single pair of long cartilages. The buccal musculature is also described.

Geographical and seasonal distributions of the seedeaters Sporophila bouvreuil and Sporophila pileata (aves: Emberizidae)

Many species in the genus Sporophila are migratory. Migration patterns, while poorly studied, may be influenced by seed production which can be very seasonal in some regions. The distribution of S. bouvreuil extends from the Amazon and Suriname south through a large part of the open regions of Brazil. Sporophila pileata, on the other hand, is found in southeastern and southern Brazil as well as Argentina and Paraguay. Both of these species migrate, but their movement patterns are poorly known. To better understand the geographical and the seasonal distributions of S. bouvreuil and S. pileata, we grouped the records into two categories: the breeding season (September to March) and the putative migration season (April to August). We found two areas of sympatry between S. bouvreuil and S. pileata in the Brazilian states of Minas Gerais and São Paulo. For S. bouvreuil we suggest that populations that breed in the Amazon migrate to the Cerrado or Caatinga, where they will encounter resident populations of the same species. These resident populations may take part in short distance migrations. Sporophila pileata, on the other hand, occur in the Cerrado and open areas within the Atlantic Forest and it is not yet possible to determine migratory tendencies or destinations in the non-breeding season.

Rediscovery of the putatively extinct ant species Simopelta minima (Brandão) (Hymenoptera, Formicidae), with a discussion on rarity and conservation status of ant species

Simopelta minima (Brandão, 1989) was originally described based on four workers collected in soil samples from a small cocoa plantation in Ilhéus, state of Bahia, northeastern Brazil. In the subsequent years after the description, this cocoa plantation was eliminated and the species was then considered extinct by the Brazilian environmental institutions. The recent rediscovery of S. minima workers in subterranean pitfall trap samples from Viçosa, state of Minas Gerais, southeastern Brazil, over 1.000 km distant from type locality, suggests that the rarity and vulnerability status of some ant species may be explained by insufficient sampling of adequate microhabitats, in time and space.

Peixes da Estação Ecológica Serra Geral do Tocantins, bacias dos Rios Tocantins e São Francisco, com observações sobre as implicações biogeográficas das "águas emendadas" dos Rios Sapão e Galheiros

Um levantamento preliminar da ictiofauna que ocorre na Estação Ecológica Serra Geral de Tocantins, situada no Sudeste do Estado do Tocantins e Noroeste do Estado da Bahia, é apresentado. A Estação Ecológica Serra Geral de Tocantins situa-se no divisor de águas entre as bacias do Rio São Francisco (Rio Sapão) e Rio Tocantins (bacias dos Rios Novo, Balsas e Manuel Alves). A cabeceira comum ou "água emendada" do Rio Sapão e Rio Galheiros, este um afluente do Rio Novo, situa-se no interior da estação e é considerada na literatura como uma possível área de intercâmbio ictiofaunístico entre a bacia do Rio São Francisco e a bacia do Rio Tocantins. Trinta e cinco espécies de peixes foram registradas dentro da Estação Ecológica Serra Geral de Tocantins e em seu entorno imediato, algumas delas desconhecidas da ciência e possivelmente endêmicas da região. Um total de 111 espécies de peixes foi registrado regionalmente (incluindo espécies de peixes registrados nos trechos do Rio Sapão e do Rio Novo/do Sono abaixo da estação). O acará Cichlasoma sanctifranciscense é aqui registrado pela primeira vez na bacia do Rio Tocantins. A ocorrência desta espécie, bem como do lambari Astyanax novae, no Rio Sapão e no Rio Novo/do Sono, são considerados os únicos exemplos inequívocos de transposição natural de espécies de peixes entre as bacias do Rio São Francisco e Tocantins efetuado pelas águas emendadas dos rios Sapão e Galheiros.

Population structure of the lancelet Branchiostoma caribaeum (Cephalochordata: Branchiostomidae) in the Baía de Guanabara, Rio de Janeiro, southeastern Brazil

Population structure of the lancelet Branchiostoma caribaeum Sandevall, 1853 was studied in four surveys, corresponding to austral seasons, in a tropical bay, southeast of Brazil. Abundance was higher in the spring and was positively correlated to coarse sediments, limiting its occurrence to some sectors of the sampling area. Body length and biomass differed seasonally but not between sexes. Sexually mature individuals occurred in all seasons, suggesting continuous breeding that is typical of tropical species. Variation in the frequency of small specimens indicates temporal differences in the intensity of breeding. The body length of recruits differed from other population of lancelets and the small length which B. caribaeum attained sexual maturity in Guanabara Bay may be related to local environmental stress or the great availability of food.