Northern Coast Of Brazil Research Articles

Genetic characterisation of populations of the critically endangered Goliath grouper ( Epinephelus itajara, Serranidae) from the Northern Brazilian coast through analyses of mtDNA

The Goliath grouper ( Epinephelus itajara ) is one of the most endangered species of fish of the subfamily Epinephelinae. Slow to develop and mature, and dependent on mangrove habitats for breeding, the species also suffers intense harvesting, which has reduced drastically in numbers in many areas. To contribute to the understanding of the characteristics of E. itajara populations, we conducted a molecular genetics study of the species, focusing on populations from the Northern Brazilian coast. The mtDNA control region (D-loop) of 116 individuals from five localities (Bragança, Ajuruteua, Parnaíba, Fortaleza and Natal) was analysed, and a sequence of 499 base pairs identified. Analyses of the sequences indicated that genetic variability was generally lower in E. itajara than in other endangered species of the genus. AMOVA found no significant grouping structure among the populations. Nested Clade Analysis revealed a significant association between genetic variability and geographic distribution among only three populations (Ajuruteua, Parnaíba and Natal). Genetic diversity was higher in populations from the Amazon region, which may be related to the better conservation of mangrove habitats in this area. Therefore, the present study could be used for the implementation of conservation and management measures in order to protect and consolidate these populations.

Genetic characterisation of populations of the critically endangered Goliath grouper ( Epinephelus itajara, Serranidae) from the Northern Brazilian coast through analyses of mtDNA

The Goliath grouper (Epinephelus itajara) is one of the most endangered species of fish of the subfamily Epinephelinae. Slow to develop and mature, and dependent on mangrove habitats for breeding, the species also suffers intense harvesting, which has reduced drastically in numbers in many areas. To contribute to the understanding of the characteristics of E. itajara populations, we conducted a molecular genetics study of the species, focusing on populations from the Northern Brazilian coast. The mtDNA control region (D-loop) of 116 individuals from five localities (Braganca, Ajuruteua, Parnaiba, Fortaleza and Natal) was analysed, and a sequence of 499 base pairs identified. Analyses of the sequences indicated that genetic variability was generally lower in E. itajara than in other endangered species of the genus. AMOVA found no significant grouping structure among the populations. Nested Clade Analysis revealed a significant association between genetic variability and geographic distribution among only three populations (Ajuruteua, Parnaiba and Natal). Genetic diversity was higher in populations from the Amazon region, which may be related to the better conservation of mangrove habitats in this area. Therefore, the present study could be used for the implementation of conservation and management measures in order to protect and consolidate these populations.

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

First confirmed record of Feresa attenuata (Delphinidae) for the Northern Brazilian Coast

In Brazil only one confirmed stranding is known from an emaciated specimen collected along the southeastern coast. The aim of this work is to report a recent record of a pygmy killer whale from the coast of Maranhão State, northern Brazil. On 22 October 2005, through regular surveys conducted by Projeto Cetáceos do Maranhão team, a beach-worn skull of a pygmy killer whale was found on the Mangue Seco beach, at Caju Island, Maranhão State. The specimen was identified through peculiar features, such as a short beak, 11 teeth per row in the maxile and the distance between the anterorbital notch and the end of the toothrow. This stranding suggests that pygmy killer whales may use oceanic waters close to Maranhão continental shelf. This is the second confirmed stranding of F. attenuata for the Brazilian Coast and the first along the northern coast. The present record increases our poor knowledge on the cetacean fauna of the northern Brazilian coast.

First occurrence of Dolicholagus longirostris larvae (Maul 1948) (Osmeriformes, Bathylagidae) near the mouth of the Amazon River

The family Bathylagidae contains eight genera and 22 species, of which only five occur in the Southwest Atlantic. Until recently, only adult specimens of the bathylaginin Melanolagus bericoides had been recorded off southern Brazil, between the Santa Marta Cape and Rio Grande (31° S and 49° W). The present work reports the first occurrence of Dolicholagus longirostris larvae on the northern Brazilian coast, expanding its distribution in the Southwest Atlantic. The two specimens found were collected near the mouth of the Amazon River (02° 00' 19" N, 47° 03' 30" W, and 00° 49' 06" N, 46° 25' 09" W).

Anatomical investigation of the slender catshark Schroederichthys tenuis Springer, 1966, with notes on intrageneric relationships (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)

The slender catshark Schroedericthys tenuis Springer, 1966, originally described from two immature males, is redescribed on the basis of 12 specimens of both sexes, juveniles and adults (as well as the holotype and paratype). The supplementary specimens were collected off the northern coast of Brazil between Amapá and Pará states. Aspects of its external morphology, color pattern, dermal denticles, dentition, vertebral counts, and the cephalic, clasper and pectoral fin skeleton are described in detail and fully illustrated. These features are compared with those of congeneric species. Our observations support preliminary results of work in progress that S. maculatus Springer, 1966, S. tenuis and S. saurisqualus Soto, 2003 form a monophyletic group, mostly on the basis of neurocranial morphology, and that S. bivius (Smith, 1838) and S. chilensis (Guichenot, 1848) should be removed from Schroederichthys.

Reproductive biology and spatio-temporal distribution of Stellifer rastrifer, Stellifer naso and Macrodon ancylodon (Sciaenidae) in the Caeté estuary, northern Brazil

This study analyses the spatial and temporal distribution of the dominant Sciaenids in the Caeté estuary on the northern coast of Brazil. Samples were taken by otter trawls in four areas of the Caeté estuary between October 1996 and August 1997 six bimonthly. Stellifer rastrifer, Stellifer naso and Macrododon ancylodon presented the highest biomass out of eleven species of Sciaenidae caught. Minimum and mean length at first maturity were calculated and the main spawning periods determined. Changes in the spatio-temporal distribution of the three species were related to seasonal changes in estuarine salinity and spawning pulses. Larvae and juveniles of S. rastrifer, S. naso and M. ancylodon were found in the inner estuary while larger specimens were more abundant in the outer estuary with higher salinities. M. ancylodon spawned from October to February and rested from April to August whereas S. rastrifer and S. naso spawned throughout the year, though with two peaks, in October-December and June.

Biemna trisigmata sp. n., a new sponge from the North coast of Brazil (Demospongiae, Poecilosclerida)

A new species of Biemna Gray, 1867, B. trisigmata sp. n., is described from the northern Brazilian coast, Amap State. The new species is compared to other tropical West Atlantic species of Biemna, from which it differs in having three categories of sigmas and two categories of microxeas.

Food categories reconstruction and feeding consumption estimates for the Sciaenid Macrodon ancylodon (Bloch & Schneider), and the congeneric fishes Stellifer rastrifer (Jordan) and Stellifer naso (Jordan) (Pisces, Perciformes) in the Caeté Estuary, Northern Coast of Brazil

A quantitative method to estimate fish feeding consumption and energy intake from different food categories through the reconstruction of ingested preys based on hard not digestible body structures is presented. In order to establish the equations of the functional relationships between preys weight and body structures, stomachs of 1.086 specimens of Macrodon ancylodon (Bloch & Schneider, 1801), Stellifer rastrifer (Jordan, 1889), and Stellifer naso (Jordan, 1889) fish species were dissected. Consequently, preys reconstruction enabled a quantitative evaluation of food categories consumption. Results indicate a marked difference in diet composition and energy requirements according to fish species ontogenetic development.

Critical comments on the South Atlantic puzzle of reef fish biogeography [J.‐C. Joyeux, S.R. Floeter, C.E.L. Ferreira & J.L. Gasparini (2001) Biogeography of tropical reef fishes: the South Atlantic puzzle. Journal of Biogeography, 28, 831–841

Critical comments on the South Atlantic puzzle of reef fish biogeography [J.‐C. Joyeux, S.R. Floeter, C.E.L. Ferreira &amp; J.L. Gasparini (2001) Biogeography of tropical reef fishes: the South Atlantic puzzle. <i>Journal of Biogeography</i>, 28, 831–841

Seasonal changes in density, biomass, and diversity of estuarine fishes in tidal mangrove creeks of the lower Caeté Estuary (northern Brazilian coast, east Amazon)

The present study investigated the assemblage of fish species in an intertidal mangrove forest during high tide in a macrotide region. We describe the seasonal changes in the fish assemblage composition in relation to biomass, density, and species number in tidal creeks of the Furo do Meio, Caete Estuary, Brazil. A total of 29 107 individuals of 49 species in 26 families were caught using a block net. Their total weight was 526 kg (total density 0.11 ind. m -2 and total biomass 2.1 g m -2 ). Analysis of the catch data showed that the number of species varied significantly between creeks, and that total fish biomass differed significantly between seasons. The densities and biomass of the 2 most important species, Cathorops pleurops and Colomesus psittacus, were significantly different between seasons. The densities and biomass of C. pleurops, Pterengraulis atherinoides, Pseudauchnipterus nodosus, and Stellifer naso showed significant temporal differences. Significant differences between creeks were observed in the density and biomass of Anchovia clupeoides and Rhinosardinia amazonica. The abundance-biomass comparison (ABC) plots for the fish fauna in the creeks of the Furo do Meio showed that the dominant species increased in number and weight at the beginning of the rainy season. As a result of increased rainfall in March and April, salinity declined to values between 6 and 8 psu. At that time, the dominant species made up more than 60% of the total biomass and density and Hill's index of diversity (N1) declined, whereas the number of species (NO) and evenness (E2) did not change. After April, rainfall decreased, and density and biomass returned to levels similar to those before the rainy season. The number of species and the density and biomass in the mangrove tidal creeks are compared with published data for other tropical and subtropical estuaries. Migration trends were inferred from the results of the seasonal fluctuations of density and biomass of the most important species in the Furo do Meio, and are compared with data from other studies in the main channel of the Caete Estuary.

Spatial and temporal distribution of Myrophis punctatus (Ophichthidae) and associated fish fauna in a northern Brazilian intertidal mangrove forest

The mangrove forest along the northern Brazilian coast is not inundated during low tide. However, many fish species stay in the mangrove forest during this time. Tidal behaviour strategies are described for fish species that linger in the mangrove forest during low tide. The samples were taken at the end of the dry season (December 1996) and at the end of the rainy season (July 1997). Fish were captured using an ichthyotoxic plant extract (Ichthyotere cunabi). Spatial and temporal fish density and biomass were analyzed statistically. Thirty-six samples were taken with a total density of 2.8 ind m-2 and a total biomass of 17.4 g m-2 distributed among seven families and 14 species. Myrophis punctatus was the most important species in number (1.66 ind m-2) and weight (12.68 g m-2) of all catches. The total fish densities were not significantly different among areas and between months, although, total biomass differed significantly in time and space. The densities and biomass for the three most dominant species (M. punctatus, Poecilia spp. and Gobionellus smaragdus) differed significantly among species. Only the biomass of these species showed significant monthly differences. The only significant main effect on variance in the densities and biomass of M. punctatus were encountered between months. In addition, the factor area was significantly different for the variable number of species.

Oxygen isotopes versus CLIMAP (18 ka) temperatures: A comparison from the tropical Atlantic

Glacial-interglacial differences in δ 18 O values of Globigerinoides sacculifer have been mapped in the western and central tropical Atlantic using data from surface and core sediments. Glacial-interglacial differences in the western tropical Atlantic, if attributed to temperature changes only, are at odds with temperature reconstructions performed by CLIMAP. In the Ceara Rise region delta δ 18 O values exceeding 2‰ are recorded. They can only be partly attributed to changes in the precipitation-evaporation regime, i.e., higher salinities and 18 O-enriched precipitation. An additional cooling of 1–2 °C as compared to CLIMAP9s results is required to balance the δ 18 O record. Thus, temperature changes from glacial to modern times amount to 2– 3 °C in the tropical Atlantic off the northern coast of Brazil.

The distribution of Caiman crocodilus crocodilus and Caiman yacare populations in Brazil

Abstract The distribution and relationships among populations of Caiman crocodilus crocodilus and Caiman yacare were investigated throughout Brazil. Caiman c. crocodilus inhabits the drainages of the Rio Solimões/Rio Amazonas, Araguaia, Araguari, Itapicuru, Paranaiba, Negro, Tapajos, Tocantins, Xingú, and the rivers draining to the Atlantic Ocean on the northern coast of Brazil. It does not occur in the Rio Saõ Francisco. Caiman yacare is endemic to the Rio Mamoré, Rio Guaporé, Rio Paraguai and Rio Paranã river systems and all of their lowland drainages. The northernmost limit for C. yacare lies between Costa Marques (12°25'S, 64°10'W) and Guajara Mirim, Pacaas Novos on the Rio Mamoré (10°55'S, 65°15'W). Small populations of apparently hybrid individuals were observed in the upper Rio Acré, the Rio Abunã, the upper Rio Madeira, and the Rio Mamoré between Guajara Mirim and Abunã. Caiman c. crocodilus and C. yacare populations are geologically separated and morphologically distinct. The taxonomic recognition of Caiman species with overlapping distributions in the states of Mato Grosso and Mato Grosso do Sul appears to be without merit.

Eastern Venezuela Basin's Post-Jurassic Evolution as a Passive Transform Margin Basin

Passive transform margins are segments of rifted continental margins bounded by transform faults that are active during rifting and that become inactive during drifting. Examples include the northern coast of Brazil and its matching margin along the Liberia-Nigeria coast. We propose that the northern margin of the Eastern Venezuela Basin was dominantly a passive transform margin during the Cretaceous and early Paleogene, rather than a purely passive margin. Published microplate reconstructions of the southern Caribbean show Jurassic separation of the Bahamas platform from northern South America along a northwest-trending transform fault postulated to lie just northeast of Trinidad and the Guianas. We conjecture that the [open quotes]Deflexion de Barcelona[close quotes] (a northwest-trending zone of strike slip faults along the southwestern edge of the Serrania del Interior) is controlled by a basement geofracture that is the onshore expression of Jurassic transform fault southwest of and subparallel to the southwestern Bahamas transform. Implications of this conjecture for the Eastern Venezuela Basin include: (1) absence of McKenzie-type regional crustal stretching, Mesozoic thermal anomaly, and Mesozoic thermal-tectonic subsidence; (2) abrupt rather than gradual seaward changes in crustal thickness; (3)abrupt lateral changes in thickness and facies of Mesozoic sediments, as in the Piaui-Ceara basins ofmore » northern Brazil; (4) tendency for structural styles developed during Neogene compression to include more strike-slip faults and en enchelon fold sets (because of reactivation of Mesozoic transforms) than would be expected by structural inversion of a purely passive margin.« less

Rainfall and surface kinematic conditions over central Amazonia during ABLE 2B

Meteorological and chemical data collected during the wet season Amazon Boundary Layer Experiment near Manaus, Brazil, are used to investigate the rainfall, rainfall systems, and surface kinematics of the central Amazon basin wet season. Analysis of the Geostationary Operational Environmental Satellite (GOES‐West) imagery indicates that, based on location of initial development, there are three main types of convective systems which influence a mesoscale network near Manaus. Coastal Occurring Systems (COS) are mesoscale to synoptic scale sized systems of generally linear orientation which form along the northern coast of Brazil and propagate across the Amazon basin. The Basin Occurring Systems (BOS) form in the basin east and north of Manaus and also propagate toward the network. Locally Occurring Systems (LOS) form in and around the mesoscale network and rarely are larger than 1000 km2. Composites of hourly rainfall totals and satellite‐derived cloud cover show that rainfall and cloudiness associated with COS occurred in the network between 1400 and 1800 UT, while BOS rainfall was most common between 1000 and 1400 UT. Little rain or cloud cover was seen before 1600 UT during days influenced by LOS. Chemical analysis of the rainwater delivered by these systems also shows significant differences in the concentrations of formate, acetate, pyruvate, sulfate, and hydrogen ion. In addition, aerosol concentrations measured near Manaus indicate large influxes of aerosols (sodium, chlorine, and silicon) into central Amazonia after the passage of BOS and COS. The satellite‐based classification indicates a definite intraseasonal variation in regard to the dominant rain‐producing system. During April 11–20, BOS occurred on 8 days and produced 98% of the rainfall. Eight COS occurred during April 21 to May 3 and accounted for 89% of the rainfall. The final part of the experiment, May 4–14, was influenced solely by LOS. Harmonic analysis of surface divergence during this period exhibits a peak at 24 hours. This peak, representing the diurnal heating cycle, does not exist earlier in the experiment when BOS and COS are more frequent.

Origin and Significance of Evaporites in Basins Around Atlantic Margin

Immediately before the rifting and disruption of Pangaea, that great continent lay athwart the Triassic equator. The continental interior was arid, and isostatic adjustments following rifting produced drainage flowing away from the newly formed elongate troughs. These climatic and physiographic conditions inevitably led to the deposition of evaporites as the sea entered the rift zones whose margins now form the edges of the continents around the Atlantic. As a result, the sediment sequence in the Atlantic coastal basins shows a change from continental to evaporitic to normal marine conditions, except where evaporites were deposited directly onto newly formed oceanic crust. The age of these evaporites gives a chronology for the establishment of a permanent body of water be ween the separating fragments of Pangaea. The North Atlantic appeared in the north in Late Triassic time and became established farther south by the Middle Jurassic. The South Atlantic became established during Aptian time. The Gulf of Mexico was formed in Middle Jurassic time by the subsidence of continental material. The union of the two parts of the incipient ocean occurred during or later than Albian time and the resulting free circulation of water in the Atlantic eliminated the restriction necessary for the continued accumulation of evaporite deposits. No such deposits are known, therefore, from the northern coast of Brazil or from the northern side of the Gulf of Guinea.

Preliminary results of drift-bottle releases and recoveries in the Western Tropical Atlantic

In February-March 1963, during the Equalant Operation for the ICITA program, 476 drift-bottles were released at the equatorial waters off the northern Brazilian coast (01ºS to 09ºN and 043ºW to 053ºW). Thirty-five, bottles were recovered (7,4%). Those were classed in five groups according to their different velocity ranges and areas of recovery (Trinidad Island; Lesser Antilles; Caribbean and Florida area; north Brazil; northeastern Brazil). The recoveries of bottles released within 300 nm off the northern and northeastern coast of Brazil confirmed a strong current along the north and northeast coast in northwestern direction (South Equatorial Current and branches). In late February-early March the bottles showed maximum velocities of this current (3,6 knots). The region off the northern coast of Brazil, between 05ºN and 09ºN up to 050ºW seems to have been under the influence of an eastward component of the surface current in this same period, while at late March this influence appears to have been weaker. In the region from Trinidad Island to Yucatan Peninsula the current seems to be stronger on the northeastern side of the Caribbean Sea.

The Caetano Prospect: An Eighteenth-Century View of Recife in Brazil

No city of south america has been more frequently or more carefully depicted in views of all kinds than Recife, the capital of Pernambuco, a port on the northern coast of Brazil, which this year is celebrating the 300th anniversary of one of the great events in its history. The iconography of Recife begins with the Dutch, who are responsible for its growth as a town. Before their conquest of Pernambuco in 1630, Recife had been only a village of fishermen dependent upon the old Portuguese town of Olinda, located a short distance to the north. Olinda, however, lacked port facilities, for it was built on hills dominating an open beach. Recife, on the other hand, is located at the confluence of the rivers Beberibe and Capibaribe, where there is a deep harbor protected from the sea by reefs of sandstone, which gives the place its name. The situation was, therefore, ideal for the needs of the Dutch West Indies Company, which for commercial purposes had brought about the conquest of the rich sugar and dye-wood-producing Portuguese colony of Pernambuco.