Northeastern Coast Of Brazil Research Articles

Behavioural seasonality of the estuarine dolphin, Sotalia guianensis, on the north-eastern Brazilian coast

This study tested the association between variation in precipitation and behavioural seasonality in Sotalia guianensis , at the Curral inlet (6o13′00″S 35o3′00″W) in north-eastern Brazilian coast. From October 1999 to September 2003, observations were carried out four days a month. Behaviours were registered instantaneously each five minute interval. The observation period consisted of six hours into the daytime (0600 to 1700 h). Two observers inspected the area simultaneously, from a fixed location at the top of the cliff. During June to November, socialization (Md JN = 1.524; Md DM = 0.667; U = –2.848; P = 0.004) and forage (Md JN = 3.268; Md DM = 1.762; U = –2.881; P = 0.004) were significantly higher than from December to May, although the number of individuals (Md JN = 6.000; Md DM = 5.000; U = –1.395; P = 0.163) did not change over the year. Such behavioural seasonality was not associated with dry/rainy periods (number of individuals: Md RS = 5.000; Md DS = 6.250; U = –1.672; P = 0.095; socialization: Md DS = 0.947; Md RS = 1.464; U = –0.858; P = 0.391; and forage: Md DS = 3.017; Md RS = 2.292; U = –1.506; P = 0.132). These results support behavioural seasonality in an equatorial odontocete population.

A new species of Euprognatha Stimpson, 1871 (Crustacea, Brachyura, Inachoididae) from off coast of northeastern Brazil

A new species of Euprognatha Stimpson, 1871 from off coast of Brazil (Canopus Bank, 02º15.3'00"S - 38º16.0'00"W) is described and illustrated, namely Euprognatha limatula n. sp. The new species is compared to its congeners. Lectotypes are designated for E. acuta A. Milne-Edwards, 1880 and E. granulata Faxon, 1893. A key to the species of Euprognatha is provided.

Population analysis of Scomberomorus cavalla (Cuvier, 1829) (Perciformes, Scombridae) from the Northern and Northeastern coast of Brazil

Scomberomorus cavalla is a pelagic fish species widely distributed on the Atlantic west coast, and a noticeable decrease in its capture level in the USA and Gulf of Mexico is occurring, compared to the levels reached by the species in the past. Likewise, in some areas of Brazil, there has been indication of over-harvesting. However, there are no molecular studies focusing on the management of such an important item. Thus, in the present study, 380 nucleotide base pairs of the mitochondrial DNA D-Loop region of samples from Macapá, Bragança, and Fortaleza were sequenced. Phylogenetic and population analyses revealed that there is only one panmitic population, and low levels of genetic variability were verified. These results, as well as the noticed over-harvesting of S. cavalla, represent very important data to determine the management of such stock in order to prevent a collapse or the risk of future extinction.

Fishes (Elasmobranchii and Actinopterygii) of Picãozinho reef, Northeastern Brazil, with notes on their conservation status

Shallow reefs on the northeastern coast of Brazil are rich, productive and diverse environments, with great ecological and economical importance. Picãozinho is located 1,500 m off the coast of João Pessoa city, Paraíba state, NE Brazil. The aim of this work is to provide an updated list of the reef fishes of Picãozinho, based on a survey of approximately 350 hours of direct observation using free dive techniques, and complemented by collection data and other unpublished records. A total of 102 species of 43 families were recorded. Of these, 36 are new occurrences for the reef and seven are species that have been recently resurrected from synonymy, mainly with Caribbean species previously cited for Brazil.

Total-Hg and organic-Hg in Cephalopholis fulva (Linnaeus, 1758) from inshore and offshore waters of NE Brazil

To investigate whether source proximity or bioavailability is the major factor controlling both Hg concentration and Hg speciation in marine fishes, total- and organic-Hg content in muscle and liver tissues from different populations of Cephalopholis fulva (piraúna) from inshore and offshore waters of the Brazilian northeastern coast were analyzed. Average total-Hg in muscle (104 ng x g(-1) w.w.) and liver (2,865 ng x g(-1) w.w.) tissues, as well as organic-Hg concentrations in muscle (169 ng x g(-1) w.w.) and liver (1,038 ng x g(-1) w.w.), were much higher in the offshore population of C. fulva than in the inshore ones. In the inshore population total-Hg and organic-Hg average concentrations in muscle tissue were similar and reached only 49 ng x g(-1) w.w., while in liver they reached 412 ng x g(-1) w.w. for total-Hg and 180 ng x g(-1) w.w., for organic-Hg. Concentrations of both Hg species in the two populations were higher in liver than in muscle. The average percentage contribution of organic-Hg to the total Hg content was higher in muscle (98-100%) than in liver (42-53%), but similar between the two populations. Total-Hg and organic-Hg concentrations in muscle and liver from the offshore population showed significant (P < 0.05) positive correlation with fish length. However, in the inshore population only the total-Hg and organic-Hg in muscle tissues correlate significantly with fish size. Although the coastal environments are enriched in total Hg relative to open waters, the significant higher Hg concentrations in the offshore population of C. fulva and the significant correlation found between organic-Hg in liver with fish size suggest higher bioavailability of Hg in offshore waters relative to inshore ones.

An updated checklist of decapod crustaceans (infraorders Astacidea, Thalassinidea, Polychelida, Palinura, and Anomura) from the northern and northeastern Brazilian coast

A checklist of the decapod crustacean species from the infraorders Astacidea, Thalassinidea, Polychelida, Palinura, and Anomura from the northern and northeastern (N/NE) Brazilian coast based on literature and material deposited in the carcinological collection of the Universidade Federal de Pernambuco, Recife, Brazil, is provided. The list includes marine and estuarine species reported at least once to each of the studied area, including the oceanic islands and banks along the N/NE Brazil. A total of 146 species is reported, corresponding to an increase of 32.7% when compared to the data published in Paulo Young’s Catalogue (1998). The most representative infraorder concerning number of species is Anomura, represented in N/NE Brazil by 90 species and 10 families, followed by Thalassinidea, with 36 species and 6 families, Palinura, with 14 species and 4 families and, finally, Astacidea, which comprises 6 species and 2 families. Families with highest species richness were Porcellanidae (20), Diogenidae (19), Paguridae (18) and Galatheidae (15), all of them included in the infraorder Anomura. Zoogeographic affinities regarding the species are briefly discussed

Spatial and temporal variation of Hypnea musciformis carrageenan (Rhodophyta - Gigartinales) from natural beds in Rio de Janeiro State, Brazil

Hypnea musciformis (Wulfen in Jacqu.) J. V. Lamour. is a native source of kappa-carrageenan, a commercially important galactan, exploited for decades on the northeastern Brazilian coast. Further studies to obtain information about the effects of abiotic factors on the carrageenan yield and quality of specimens from the southeastern Brazilian coast (Rio de Janeiro State) are needed. In this study, the carrageenan yield and quality of H. musciformis was analyzed over a period of 1 year in populations from Rio de Janeiro state. One epiphytic population was collected at a site situated at the entrance of the Sepetiba Bay (Praia Vermelha), another in the middle of the bay (Praia Grande) and a third (Praia Rasa) in a place exposed to the open sea. An epilithic population was also collected at Praia Rasa. In the sampling period, different changes were observed in the carrageenan yield and quality (viscosity and sulphate content) of the H. musciformis (August 1994 to June 1995) at the different sites and habitats (epilithic and epiphytic). Kappa carrageenan was the only one of its type detected. Only one population showed a correlation between viscosity and degree of sulphate content. Our analyses suggest that abiotic factors, such as water movement, desiccation stress, low salinity and extreme temperatures, were the main abiotic factors that influenced the changes in carrageenan of the populations studied. Thus, for a rational use of natural beds of H. musciformis, it is desirable to estimate the changes in carrageenan and algal biomass in the place to be exploited.

Embarcações motorizadas: uma ameaça aos peixes-boi marinhos (Trichechus manatus) no Brasil

O aumento do tráfego de embarcações motorizadas em áreas utilizadas para alimentação, descanso e reprodução pelos peixes-boi marinhos tem não só afugentado estes animais, mas resultado em potenciais casos de colisões. Este trabalho tem como objetivo relatar casos de interações entre embarcações motorizadas e peixes-boi marinhos (Trichechus manatus) no litoral Nordeste do Brasil. As interações ocorreram nos Estados do Ceará, Paraíba e Sergipe com três espécimes, sendo um destes com quatro registros. Foram observados transtornos clínicos como edema da região frontal, proptose ocular, emagrecimento e múltiplos cortes ao longo do corpo. Sendo assim, o aumento do tráfego de embarcações, e a falta de normativas e de fiscalização que assegurem a efetiva proteção de determinadas áreas, representam um risco direto para a conservação dos peixes-boi marinhos no litoral Nordeste do Brasil.

Imposex in Two Muricid Species (Mollusca: Gastropoda) from the Northeastern Brazilian Coast

Imposex is the occurrence of male sexual features in female prosobranch mollusks exposed to organotin compounds. Since imposex has measurable characteristics, it has been used as a bioindication tool for the presence of this kind of pollutants. Thus, this work aimed to monitor organotin pollution over areas under the influence of ten main harbors of North-eastern Brazilian coast. Imposex intensity was measured using the indexes VDSI, RPSI, RPLI and the percentage of imposexed females. At least one sampling site in each studied harbor showed imposex, suggesting a widespread contamination by organotin compounds. However, the observed imposex levels are lower than those obtained by other monitoring works in highly industrialized regions of Europe and Asia, confirming that organotin contamination levels are higher in the most industrialized regions of the world. Approximately 39% of all sampling sites (32 sites) did not show imposexed females, suggesting that this feature does not occur naturally in Stramonita haemastoma and Stramonita rustica.

New records of Monstrilloida Sars, 1901 (Crustacea, Copepoda) on the Brazilian northeastern coast

During a series of zooplankton surveys carried out from 2001 through 2005 off the coast of the state of Bahia, Brazil, 98 individuals of monstrilloid copepods were collected. These belong to five species (Monstrilla grandis, Cymbasoma cf. longispinosum, Cymbasoma cf. rigidum, Cymbasoma gracilis, and Cymbasoma quadridens). The first three are recorded for the first time in the Bahia coastal region. The geographical range of C. quadridens is expanded to the Brazilian northeastern coast. The results presented herein increase to nine the number of nominal species of Monstrilloida known from off Bahia; the environmental diversity of Caravelas Channel with highly productive areas and coral reef zones harbor an abundant and diverse monstrilloid fauna that should be surveyed in more detail.

New record of Laeonereis acuta (Treadwell, 1923) (Nereididae: Polychaeta) in Northeast coast of Brazil

In the present study, we report the presence of the nereidid polychaete Laeonereis acuta near to the estuarine areas of Parnaíba River, extending its distribution towards the north of the northeastern Brazilian coast.

Current distribution of the exotic copepod Pseudodiaptomus trihamatus Wright, 1937 along the northeastern coast of Brazil

Instituto Oceanografico da Universidade de Sao Paulo Departamento de Oceanografia Biologica (Praca do Oceanografico 191, 05508-120 Sao Paulo, SP, Brasil) **rmlopes@usp.br The introduction of exotic species is a major cause of depletion and extinction of native populations, a threat only surpassed by habitat destruction (Williamson, 1999). Exotic organisms may inflict negative impact upon native species by several ways, including transmission of pathogens and parasites, genetic degradation, habitat utilization, direct predation or competition for food, and other food web interactions (Williamson, 1996). Aquaculture activities account for a large number of accidental introductions worldwide because of non-intentional releases of small-sized organisms associated with target imported species (Carlton, 1996; Weigle

Maturation of Squalus mitsukurii and Cirrhigaleus asper (Squalidae, Squaliformes) in the southwestern equatorial Atlantic Ocean

Specimens of Squalus mitsukurii (n = 206) and Cirrhigaleus asper (n = 93) were opportunistically collected from the catches of a research vessel using traps and benthic longlines off the coast of northeastern Brazil between March 1997 and August 2002. For both species, larger females than males were captured. Catches of S. mitsukurii were biased toward females (1:4.6), while no significant disequilibrium in sexes was detected for C. asper (1:0.86). Common regressions for total length (TL) and eviscerated weight (EW) were calculated as LnEW = 3.13LnTL-6.217 (S. mitsukurii) and LnEW = 3.22LnTL-7.01 (C. asper). Based on changes to the reproductive tract, females and males of each species were categorized into several stages of maturation. Sizes at sexual maturity for female (n = 169) and male (n = 37) S. mitsukurii were 77.8 and 65.0 cm TL, respectively. Gravid S. mitsukurii had between 3 and 11 embryos that ranged in size from 2.0 to 22.5 cm TL (n = 262). No significant bias in the sex ratio of embryos was detected. A clear relationship between embryonic development and maturation of the ovary demonstrated that female S. mitsukurii are ready to ovulate immediately after parturition. Female (n = 43) and male (n = 50) C. asper approached sexual maturity at 110.0 and 91.0 cm TL, respectively. Uterine fecundity in gravid C. asper ranged from 12 to 19 embryos that varied in size between 4.0 and 21.9 cm TL. Unlike S. mitsukurii, there was no concurrent development of the ovary and embryos. The results are discussed in terms of the reproductive plasticity of S. mitsukurii and the need for further life history studies on both species.

Transcriptome analysis of expressed sequence tags from the venom glands of the fish Thalassophryne nattereri

Thalassophryne nattereri (niquim) is a venomous fish found on the northern and northeastern coasts of Brazil. Every year, hundreds of humans are affected by the poison, which causes excruciating local pain, edema, and necrosis, and can lead to permanent disabilities. In experimental models, T. nattereri venom induces edema and nociception, which are correlated to human symptoms and dependent on venom kininogenase activity; myotoxicity; impairment of blood flow; platelet lysis and cytotoxicity on endothelial cells. These effects were observed with minute amounts of venom. To characterize the primary structure of T. nattereri venom toxins, a list of transcripts within the venom gland was made using the expressed sequence tag (EST) strategy. Here we report the analysis of 775 ESTs that were obtained from a directional cDNA library of T. nattereri venom gland. Of these ESTs, 527 (68%) were related to sequences previously described. These were categorized into 10 groups according to their biological functions. Sequences involved in gene and protein expression accounted for 14.3% of the ESTs, reflecting the important role of protein synthesis in this gland. Other groups included proteins engaged in the assembly of disulfide bonds (0.5%), chaperones involved in the folding of nascent proteins (1.4%), and sequences related to clusterin (1.5%), as well as transcripts related to calcium binding proteins (1.0%). We detected a large cluster (1.3%) related to cocaine- and amphetamine-regulated transcript (CART), a peptide involved in the regulation of food intake. Surprisingly, several retrotransposon-like sequences (1.0%) were found in the library. It may be that their presence accounts for some of the variation in venom toxins. The toxin category (18.8%) included natterins (18%), which are a new group of kininogenases recently described by our group, and a group of C-type lectins (0.8%). In addition, a considerable number of sequences (32%) was not related to sequences in the databases, which indicates that a great number of new toxins and proteins are still to be discovered from this fish venom gland.

Reproductive Behavior in a Captive-Released Manatee (&lt;I&gt;Trichechus manatus manatus&lt;/I&gt;) along the Northeastern Coast of Brazil and the Life History of Her First Calf Born in the Wild

Reproductive Behavior in a Captive-Released Manatee (&lt;I&gt;Trichechus manatus manatus&lt;/I&gt;) along the Northeastern Coast of Brazil and the Life History of Her First Calf Born in the Wild

Bathymetric trends of northeastern Brazilian snappers (Pisces, Lutjanidae): implications for the reef fishery dynamic

The investigation of bathymetric distribution of five snappers caught along the Brazilian Northeastern coast by artisanal fleets through the analysis of the catch composition and relative abundance (CPUE) showed that, on the overall, fished mean size increased along depth and that particular species dominated the catch according to the depth strata. Mutton snapper, L. analis, yellowtail snapper, L. chrysurus, and dog snapper, L. jocu were mainly caught at intermediate depth (20-80m) whereas lane snapper, L. synagris, and silk snapper, L. vivanus, inhabit respectively shallow (&lt;20m) and deep (&gt;80 m) waters. Each fleet category exploited preferentially a particular combination of species and their size range. The fleet dynamic of the Northeast Brazil is technologically heterogeneous and determines the catch composition. Geographical distribution of the fishery and technical interaction between fleets and gears should be considered by the management of these species in order to maintain the sustainability of the stock and to guarantee the continuance of the resource.

Longshore transport on the northeastern Brazilian coast and implications to the location of large scale accumulative and erosive zones: An overview

Using the average directions of the principal wavefronts that approach the northeastern Brazilian coast, which are coincident with the directions of the prevailing winds, a wave climate model was defined, for approximately 3000 km of coast by construction wave refraction diagrams. A resulting sediment transport model that was obtained by numerical modeling starting with refraction diagrams, taking into account the wave approach angles and their heights permitted the reproduction, on a regional scale, of the sediment dispersion pattern. Several drift cells were identified, the limits of which were based on alterations in the direction or intensity of potential net longshore drift. Although also dependent on other factors such as the supply of fluvial sediments to the coastal zone and to wind activity, the coastal sections that present progradation, erosion or non-deposition, can be reasonably explained, in a first order approximation, by these variations. As a generalization, geomorphic drift indicator match patterns of regional scale sediment dispersal.

The most northern record of Gervais' beaked whale, Mesoplodon europaeus (Gervais, 1855), for the Southern Hemisphere

This paper reports the most northern record of Mesoplodon europaeus for the southern hemisphere based on a specimen of beaked whale that stranded on Bitupita Beach (02°53'94S; 41°16'41W), on the northeastern coast of Brazil, on 23 November 2001. Identification of this individual was based on the position of the two mandibular teeth in the lower jaw. The teeth were flattened laterally, embedded in the lower jaw at the mandibular symphysis, and located posterior to the middle of the jaw. Until recently, the distribution of this species was considered limited to the northern hemisphere of the Atlantic Ocean, based on the occurrence of stranding events and sightings. The presence of M. europaeus at lower latitudes in the southern hemisphere, and the relatively fresh condition of this carcass suggest the possible existence of a broad two-hemisphere distribution the Atlantic Ocean.

Characterization and classification of two soils derived from basic rocks in Pernambuco State Coast, Northeast Brazil

Geomorphic surfaces that present soils derived from basic rocks under warm and humid climate are unique scenarios for studying tropical soils. This paper aimed to characterize and classify two pedons derived from basalt at the Atlantic Forest Zone, Pernambuco State, Northeastern coast of Brazil. Two representative pedons (P1 and P2) were selected on a hillslope at the Cabo de Santo Agostinho municipality. Field macromorphological descriptions were carried out and soil horizon were sampled for physical, chemical, mineralogical and micromorphological characterization. The soils were classified, according to the Brazilian System of Soil Classification (and US Soil Taxonomy) as: "Latossolo Vermelho-Amarelo distroférrico argissólico" (Typic Hapludox) (P1) and "Nitossolo Vermelho distroférrico típico" (Rhodic Paleudult) (P2). Pedon 1 differs from Pedon 2 in some aspects. For instance, P1 presents more yellowish colors, absence of clay illuviation, more friable consistence and the prismatic structure undergoes transformation to angular and subangular blocks. Pedon 2 presents ferri-argilans and leptocutans which indicate that vertical and lateral illuviation of clay is an active process in their formation. These chemically poor and mineralogically uniform soils are a result of the high temperature and rainfall of the studied area.

Taxonomy and distribution of the green algal genus Halimeda (Bryopsidales, Chlorophyta) in Brazil

Halimeda is a genus of calcified coenocytic green algae with a well known ecological importance in some tropical areas. Bleached calcified segments of Halimeda may accumulate in large deposits of economic potential as is the case in the northeastern coast of Brazil. In a survey of the genus in Brazil based on recent collections and examination of abundant material deposited on Brazilian herbaria we identified seven species: Halimeda cuneata Hering, H. discoidea Decaisne, H. gracilis Harvey ex J. Agardh, H. incrassata (Ellis) Lamouroux, H. opuntia (Linnaeus) Lamouroux, H. simulans Howe and H. tuna (Ellis & Solander) Lamouroux. These species are described in detail, with emphasis on diagnostic characters. Our study has shown that the shape and size of the utricula in surface view, under scanning electron microscopy, can be utilized to discriminate some species. Fertile specimens of Halimeda cuneata and H. discoidea are reported for the first time in the region. Data on vertical and geographical distribution are presented for each species and the southern limit of the genus in the western Atlantic was extended.