We examined the spatial and temporal variations of coastal and oceanic epipelagic copepods (rainy–dry seasons of 2009) in a tropical area of the south-west Atlantic. Zooplankton samples were obtained at 48 stations along six transects perpendicular to the coast, in the subsurface water between the 25 and 3000 m isobaths, by horizontal hauls using a Multinet. Abundance (42–64,753 ind. m−3), biomass (0.08–113 mg C m−3) and daily copepod production (0.17–163.20 mg C m−3 d−1) showed longitudinal and latitudinal variability. The highest values were observed over the southern continental shelf during the dry season. Temoridae, Undinula vulgaris and Paracalanus quasimodo dominated the biomass and daily copepod production during the rainy season; while Calanoides carinatus, Calanopia americana, Clausocalanidae, Temoridae, Paracalanidae and Subeucalanidae dominated during the dry season. The copepod assemblages formed four different groups: rainy season–continental shelf (1), dry season–continental shelf (2), rainy season–continental slope (3) and dry season–continental slope (4). Temperature, salinity, chlorophyll-a and suspended particulate matter explained 45% of the productivity distribution of the dominant copepod species. This study is the first attempt to examine the biomass and daily copepod production in oceanic waters in the south-west Atlantic Ocean, and it showed that copepod biomass and production in a tropical region can be relatively high compared with other regions of the world's oceans.

To verify the movements of the rough-toothed dolphin (Steno bredanensis) on the coast of Rio de Janeiro State, south-eastern Brazil, we performed a photo-identification comparison between the catalogued individuals of Rio de Janeiro City (22°54′10″S–43°12′27″W) (N = 30) during August and September 2011 and the Cabo Frio region (22°52′46″S–42°01′07″W) (N = 41) during March and August 2011. Two photo-identified individuals from Rio de Janeiro City were resighted in the Cabo Frio region, approximately 119.7 km east of the original Rio de Janeiro sighting and two other individuals identified in the Cabo Frio region were resighted in the Rio de Janeiro City area, approximately 117.0 km west of the original sighting. This study reports the first information about the movements of the species in Brazil within these coastal areas.

The temporal and spatial variation of Paralonchurus brasiliensis density (fish per m2) in relation to environmental factors was studied on the coasts of Ubatuba and Caraguatatuba, south-eastern Brazil. The fish were collected by shrimp fishery trawl on a monthly basis from January to December, 2002. Seven depths were previously established and for each one the temperature, salinity, organic matter content and grain size of the sediment (φ) was measured. The seasonal analysis of temperature and salinity indicated the presence of the water masses South Atlantic Central Water (SACW) and Coastal Waters (CW) acting in the study area. A total of 29,808 fish were collected during the study period. The highest densities were registered during the summer and autumn indicating an association with CW. The fish population moved to shallow depths during the intrusion of the cold water mass, SACW. The highest densities were registered in depths where the sediment composition ranged from fine sand to silt–clay. Thus, the temperature and type of the sediment are the main environmental factors which affect the spatial–temporal variation of P. brasiliensis density in south-eastern Brazil.

The present paper provides the first record of the brachyuran crab species as by-catch from shrimp fishery practices in northern Rio de Janeiro State, south-eastern Brazil (21°30′S–21°50′S). Monthly samples were collected from April 2006 to March 2007 along the coastal fishing ground, from 0 to 4 nautical miles offshore and from 10 to 15 m depth. Eight species and 6833 crab specimens were recorded: Arenaeus cribarius (N = 11), Callinectes ornatus (N = 5613), Cronius rubber (N = 16), Hepatus pudibundus (N = 523), Libinia ferreirae (N = 202), Persephona mediterranea (N = 1), P. punctata (N = 466) and Portunus spinimanus (N = 1). A seasonal pattern of the crabs' occurrence was not found. The catches per unit effort values of C. ornatus were significantly greater than the other crabs and its high number indicates a resident pattern along the coastal fishing ground in the study area. The by-caught specimens of C. ornatus can be used as bait in Balistidae (triggerfish) fishery practice by the local fishermen, but the other crab species are discarded after by-catch.

A comparison between the diet of the franciscana and the boto-cinza is presented through the proximate-composition and caloric value of their main prey. The fish Stellifer cf. rastrifer, Pellona harroweri, Anchoa filifera, Isopisthus parvippinnis and Trichiurus lepturus and the squids Loligo sanpaulensis and L. plei were analysed for water, protein, lipid and mineral contents and gross energy (GE). The fish are more important in the diet of the boto-cinza and squids are consumed mostly by the franciscana. Loligo sanpaulensis had the higher water content and protein was the largest fraction of the organic matter in all prey species. Squids presented greater GE values than fish. The data on prey composition and energy from this study are the first for these South American dolphins.

Descriptions of hexactinellid sponges collected by the RV ‘Marion Dufresne’ MD55 expedition on the Vitória–Trindade seamounts chain (off Espírito Santo State, south-eastern Brazil) in 1987 and stored in the MNHN (Muséum National d'Histoire Naturelle in Paris) are presented. Hyalonema (Cyliconema) conqueror sp. nov. (the first finding of this subgenus in the Atlantic Ocean) and H. (Prionema) dufresnei sp. nov. (the second record of this subgenus for the Atlantic Ocean) are described as new species. The holotype of H. (C.) conqueror sp. nov. was collected with a ROV at Campos Basin (off Rio de Janeiro State, south-eastern Brazil), while the paratypes originated from Vitória–Trindade seamounts chain and off Bahía State (eastern Brazil). Other hexactinellids reported here, Farrea sp., Sarostegia aff. oculata, Aphrocallistes aff. beatrix, Dactylocalyx aff. subglobosus and Euplectella suberea were known before to be widely distributed in the Atlantic Ocean. The total number of hexactinellid sponges known from Brazil has risen to 15 and from the south-western Atlantic to 23.

The present study aims to evaluate the vertical distribution of intertidal benthic organisms in different periods of the year, relating them to tide, air temperature, height and wave periodicity in breakwaters off the northern Rio de Janeiro State, and to compare the zonation at two sites (Pier and Barra) with distinct hydrodynamics, due to different wave swell. Quadrats of 400 cm2 were sampled by a photoquadrat method. The upper limit of the marine organisms was higher at the Barra site (intertidal zone of 3.8 m) than at the Pier site (intertidal zone of 2.2 m). The littoral fringe assemblage did not show significant differences between sites, but a larger range of this fringe and the upper eulittoral band at Barra was quite evident. This site was mostly characterized by species of more exposed areas such as Chaetomorpha sp. and Perna perna in the upper and lower eulittoral bands, and by C. teedii and Ulva fasciata in the sublittoral fringe. A seasonal difference was identified in the air exposure degree at the Pier site, which was higher in October 2005 and February 2006. The air temperature and wave height and periodicity differed significantly among the four studied periods. The typical seasonal species were F. clenchi (July 2005 and October 2005), Gigartina domingensis (July 2005), Grateloupia sp. (October 2005) and Porphyra acanthophora (October 2005 and February 2006). The intermediate benthic band of the intertidal zone occupied a narrow zone, changing its spatial location according to the season of the year. The hypothesis of annual variation of the benthic community zonation according to the seasonal variability of tides, air temperatures and wave's height and periodicity was accepted for the intermediate band of the intertidal zone, due to the taxonomic differences and the abundance of dominant species in the four seasons. The difference in the vertical distribution of the intertidal benthic assemblages of both breakwaters highlights a distinct wave exposure condition, and reflects the breakwaters' orientation and the wave swell at each site.

In the present study, we evaluate the influence of biotic and abiotic factors on temporal fluctuations of Sargassum filipendula in a subtropical shore. Monthly algal samples, abiotic components, amphipod grazer density, and epiphyte biomass were obtained from a Sargassum bed in south-eastern Brazil. Density of S. filipendula fronds decreased during the sampling period, whereas dry mass was more constant, although with a noticeable reduction in the warmer months. Hypnea musciformis was the most frequent epiphyte on S. filipendula, occurring in all sampling periods, although with significant temporal variation. Sargassum filipendula density and dry mass were both influenced by epiphyte dry mass, temperature, and amphipod grazers. Sargassum filipendula biomass negatively influenced total epiphyte biomass, whereas H. musciformis biomass was positively influenced by phosphate, nitrite, and S. filipendula density and negatively influenced by S. filipendula dry mass and amphipod grazer abundance. Algal temporal fluctuations can be related to local abiotic and biotic factors, but the variation observed for S. filipendula and its epiphytes suggest that these factors have quite distinct effects for these algae.

The effects of sublethal concentrations of the insect growth regulators (IGRs) diflubenzuron and methoprene on some fitness components of an Aedes aegypti (L.) population in south-eastern Brazil were investigated. The fourth instar larvae of the mosquito were exposed to 20 ppb methoprene and 3 ppb diflubenzuron, and adult survivors were evaluated for fitness parameters, including body size and biomass, fecundity, fertility, longevity and symmetry. The sublethal concentrations had negative effects on longevity, but biomass, fecundity and fertility were not affected by either IGR. In separate experiments, A. aegypti individuals' surviving concentrations of 2, 3 and 3.5 ppb diflubenzuron and 5, 10 and 20 ppb methoprene were used for morphological analyses (size and symmetry). Diflubenzuron had negative effects on the mosquito's body symmetry. The observed decreases in longevity and symmetry may have negative impacts on the population dynamics of A. aegypti.

In this note we present new records of Pontoporia blainvillei stranded along the north-eastern coast of the Rio de Janeiro State from 1999 to 2007. Three dolphins were found in the known distribution of the isolated population on the northern coast of Rio de Janeiro and showed evidence of entanglement in fishing nets. Surprisingly, one dolphin (GEMM 140) was found in Rio das Ostras, only 6.5 km south of the previously known limit of the species' distribution. However, the stranding data presented here support the hypothesis of the discontinuous distribution of this species.

Reef fish community structures at three sites in the state of Rio de Janeiro (Pedra Vermelha (PV), Cabo Frio Island—Arraial do Cabo; Mãe Island (MI), Itaipu—Niterói; Comprida Island (CI), Cagarras Archipelago—Rio de Janeiro) were investigated to assess differences in fish species composition, density and distribution of trophic groups, between sites, correlating the observed patterns of fish distribution with environmental factors. Thirty-six visual strip-transects yielded 67 species of 34 families. Studied locations shared at least 40% of all species, mostly of western Atlantic distribution. The three sites presented significant differences on diversity, density and species dominance. CI presented the highest values, except for total density, which was higher at PV, probably due to its partial degree of protection. MI showed the lowest values, suggesting possible impacts from the proximity to the shore. The main trophic categories were omnivores followed by mobile invertebrate feeders, in similarity to what was previously observed for south-eastern Brazil. Inherent habitat features of each location regarding depth, declivity, visibility and rugosity resulted in different species distribution and dominance patterns.

Mercury (Hg), cadmium (Cd) and zinc (Zn) concentration were analysed in muscular and liver tissues of two cetacean species, franciscana Pontoporia blainvillei and boto-cinza Sotalia guianensis, in order to compare their contamination levels in northern Rio de Janeiro State, south-eastern Brazil. The cutlassfish, Trichiurus lepturus, which is the preferential prey of the boto-cinza, have also been analysed. Liver tissue always presented higher concentrations when compared with muscle samples for all the studied metals. The boto-cinza showed higher concentrations for all metals in both tissues than in the franciscana, and the only exception was Cd. This result is probably related to the difference in size prey preference of each cetacean. Mercury was the only element that presented significant positive correlations with body length and age in both cetacean species. The cutlassfish showed rising Hg concentrations with weight and total length, suggesting a possible mercury pathway for marine mammals' contamination.

The canopy disturbance regime and the influence of gap methods on the interpretation of forest structure and dynamics were evaluated in a tropical semi-deciduous forest in south-eastern Brazil. We encountered a gap density of 11.2 gaps ha−1 and an average size which varied from 121 to 333 m2 depending on the gap delimitation method considered (minimum gap size was 10 m2). Although average size was slightly higher, the median value obtained (78 m2) was comparable to other tropical forest sites and the gap size-class distribution found supported the pattern described for such forest sites. Among 297 gap makers, snapping and uprooting were the most common modes of disturbance. The number and basal area of gap makers were good predictors of gap size. Almost 25% of all gaps suffered from repeated disturbance events that brought about larger gap sizes. Such processes, along with delimitation methods, strongly influenced the estimation of turnover rate and therefore the interpretation of forest dynamics. These results demonstrated the importance of further studies on repeated disturbances, which is often neglected in forest studies.

The composition of anuran assemblages was studied in 16 streams at the Serra do Cipó, south-eastern Brazil, in which 26 anuran species were found. Volume and isolation level of stream sections of 150 m were estimated; tadpoles, adult anurans, and potential tadpole predators were searched for over 16 consecutive months. Stream size, isolation, richness and diversity of tadpole predators, and some additional physical and biotic variables were measured and related to anuran species richness. Smaller streams tended to shelter more anuran species than larger ones, but neither stream size nor stream isolation explained variations in anuran species richness. Anuran species richness tended to increase with tadpole predator diversity. Tadpole species richness was influenced by predator species richness, and was highest when there were seven types of tadpole predators present. The distribution of few anuran species could be clearly related to particular physical and biotic variables. The behavioural flexibility of anurans and the similarity among streams may have contributed to this pattern.

A new species of leptodactylid frog is described from Parque das Mangabeiras, in Belo Horizonte, Minas Gerais, south-eastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and is characterized by medium size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger and toe discs with well-developed scutes, a weakly developed stripe on the upper lip, dorsum, arm, leg, and foot dark brown with small irregular brown and black dots, and absence of red and yellow spots in live specimens. The descriptions of the tadpoles and vocalizations, and information on natural history are provided. Hylodes perplicatus (Miranda-Ribeiro), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.