Transandean railroads: the interruption of service and prospects for resumption

Building the infrastructure and then operating a railroad which starts on the Pacific coast of South America and which, a few score kilometres inland, must climb close to 4,000 metres above sea level in the Andes mountains has always presented challenges both for the civil engineers responsible for its construction and for the managers in charge of its operation.As at mid-2001, two of the four transandean railroads that ran 20 years ago are out of service, owing to adverse weather conditions, and a third is not operating as a result of institutional problems.Nevertheless, two of the three railroads that are now shut down could resume service soon. Furthermore, there is a possibility that a new transandean railroad could be built that would cross the Andes mountains further south, at an altitude of less than 1,750 meters.

Identification and phylogenetic inferences on stocks of sharks affected by the fishing industry off the Northern coast of Brazil

The ongoing decline in abundance and diversity of shark stocks, primarily due to uncontrolled fishery exploitation, is a worldwide problem. An additional problem for the development of conservation and management programmes is the identification of species diversity within a given area, given the morphological similarities among shark species, and the typical disembarkation of processed carcasses which are almost impossible to differentiate. The main aim of the present study was to identify those shark species being exploited off northern Brazil, by using the 12S-16S molecular marker. For this, DNA sequences were obtained from 122 specimens collected on the docks and the fish market in Bragança, in the Brazilian state of Pará. We identified at least 11 species. Three-quarters of the specimens collected were either Carcharhinus porosus or Rhizoprionodon sp, while a notable absence was the daggernose shark, Isogomphodon oxyrhyncus, previously one of the most common species in local catches. The study emphasises the value of molecular techniques for the identification of cryptic shark species, and the potential of the 12S-16S marker as a tool for phylogenetic inferences in a study of elasmobranchs.

Low levels of genetic diversity depicted from mitochondrial DNA sequences in a heavily exploited marine fish (Cynoscion acoupa, Sciaenidae) from the Northern coast of Brazil

The acoupa weakfish (Cynoscion acoupa - Sciaenidae) is a marine species of croaker with estuarine-dependent behavior, found in the western Atlantic from Panama to Argentina. It is one of the most exploited food fish on the northern coast of Brazil. In this study, DNA sequences were determined from the entire control region (D-loop) of the mitochondrial genome of 297 individuals collected during seven different months between December 2003 and August 2005 on the northern coast of Brazil (Amapá and Pará). Genetic variability expressed by haplotype (h = 0,892) and nucleotide (p = 0,003) diversities were low compared to other heavily exploited marine fish species from the western Atlantic and eastern Asia. AMOVA depicted a lack of genetic structuring among the samples from different years, indicating the presence of a single stock of C. acoupa within the sample area. The possible reasons for the low levels of genetic diversity are discussed. These results demonstrate a need for the monitoring of C. acoupa harvesting and the preservation of the estuaries within its geographic range, considering that this large fish depends on estuarine ecosystems during part of its life cycle.

Population structure of Lutjanus purpureus (Lutjanidae - Perciformes) on the Brazilian coast: further existence evidence of a single species of red snapper in the western Atlantic

ABSTRACT: The present study focus on the mitochondrial control region to investigate phylogeographic patterns and population structure in Lutjanus purpureus, and to evaluate the genetic similarity between L. purpureus and L. campechanus. For the initial analysis, 810 base pairs sequence from control region were obtained from 239 specimens of L. purpureus collected from four localities off the Brazilian coast. The results revealed the presence of a single panmictic population characterized by high values of genetic diversity. The 299 base pairs hypervariable portion were used for the combined analysis of L. purpureus and L. campechanus, being 275 haplotypes identified in the 414 specimens. Phylogenetic tree and haplotype network did not indicate phylogeographic substructuring between the two species, but rather an intense intermingling of individuals. Considering their marked morphological similarity, the molecular data presented here indicatethat only one species of red snapper exists in the western Atlantic.

Effect of coastline properties and wastewater on plankton composition and distribution in a stressed environment on the north coast of Olinda-PE (Brazil)

Foi realizado um estudo sobre a estrutura das comunidades planctônicas ao longo das praias de Casa Caiada e Rio Doce (Pernanbuco, Brasil). A área de estudo sofre grande influência antrópica onde as condições ambientais são controladas pela presença de estruturas costeiras, reduzindo a intensidade da circulação neste ambiente; e pelos efluentes clandestinos de esgoto que aportam águas poluídas para dentro do sistema protegido. Os resultados obtidos indicam que nas zonas protegidas as águas apresentam alta turbidez, temperaturas elevadas, salinidades reduzidas e altas concentrações de nutrientes e oxigênio. Estas condições são responsáveis pela redução da diversidade do plâncton e pelo aumento da biomassa das espécies mais resistentes. As diferenças registradas com respeito a áreas similares, porém não impactadas, parecem indicar que a estrutura planctônica pode ser usada como um indicador da qualidade ambiental, sugerindo uma baixa qualidade das praias em estudo.

Model of wetland development of the Amapá coast during the late Holocene

Os tipos de vegetação atual, sequências sedimentares, dados de pólen e datações por radiocarbono obtidas em três testemunhos de sedimento da planície costeira de Calçoene foram utilizados para estabelecer uma história paleoecológica durante o Holoceno superior das zonas úmidas costeiras do Amapá conforme as mudanças no regime de inundação, nível do mar e clima. Baseado nestes três registros, quatro fases de desenvolvimento da vegetação são apresentadas e provavelmente refletem a interação entre o fluxo de energia na acumulação do sedimento e a influência das águas salobras e doces na vegetação. Este trabalho sugere alternâncias entre períodos caracterizados por influências marinha e fluvial. O perfil longitudinal não revelou a ocorrência de manguezais nos sedimentos depositados por volta de 2100 anos A.P. Durante a segunda fase, a lama preencheu progressivamente as depressões e canais de maré. Provavelmente, os manguezais iniciaram seu desenvolvimento nas margens dos canais, e os campos herbáceos nos setores elevados. A terceira fase é caracterizada por uma interrupção no desenvolvimento dos manguezais e a expansão da vegetação de várzea devido a uma diminuição na influência das águas marinhas. A última fase é representada pela expansão de manguezais e várzeas. A correlação entre os padrões atuais de distribuição das unidades geobotânicas e a paleovegetação indica que os manguezais e as florestas de várzea estão migrando sobre os campos herbáceos nos setores topograficamente mais elevados do litoral em estudo, o que pode estar relacionado a um aumento do nível relativo do mar.

Spatial distribution of the amazon river prawn Macrobrachium Amazonicum (Heller, 1862) (Decapoda, Caridea, Palaemonidae) in two perennial creeks of an estuary on the northern coast of Brazil (Guajará Bay, Belém, Pará)

Macrobrachium amazonicum é o crustáceo dulcícola mais frequentemente consumido pelas populações ribeirinhas da Amazônia. Entretanto, apesar de sua relativa abundância e vasto conhecimento da espécie a partir de dados de cultivo, pouco se conhece sobre sua biologia no ambiente natural, especialmente quanto à forma de utilização de canais fortemente influenciados pelas marés. Amostras desse camarão foram coletadas em setembro/06 (período seco) e março/07 (período chuvoso), em dois canais perenes da Baía do Guajará, Pará, utilizando armadilhas (matapis) como as utilizadas pelos pescadores locais para identificar a distribuição espacial dos organismos. Os canais de maré são utilizados por camarões de todos os tamanhos nas duas estações do ano, inclusive para a reprodução. A maior abundância de indivíduos da espécie foi encontrada no período seco, nas áreas a montante dos canais. Postula-se que a abundante matéria orgânica alóctone e a busca de locais protegidos podem ser os fatores que explicam a concentração da abundância e da atividade reprodutiva nas áreas a montante dos canais.

Frugivory by the White-bearded Manakin (Manacus manacus, Pipridae) in restinga forest, an ecosystem associated to the Atlantic forest

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Environmental factors modulating the abundance and distribution of Callinectes danae (Decapoda: Portunidae) from two areas of the southeastern coast of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Environmental factors influencing the distribution of three species within the genus Persephona Leach, 1817 (Crustacea, Decapoda, Leucosiidae) in two regions on the northern coast of Sao Paulo State, Brazil

Patterns of spatio-temporal distribution of Brachyura are determined by the interaction among life history traits, inter and intraspecific relationships, as well as by the variation of abiotic factors. This study aimed to characterize patterns of spatio-temporal distribution of Persephona lichtensteinii, Persephona mediterranea and Persephona punctata in two regions of the northern coast of Sao Paulo State, southeastern region of Brazil. Collections were done monthly from July 2001 to June 2003 in Caraguatatuba and Ubatuba, using a shrimp fishery boat equipped with double-rig nets. The patterns of species distribution were tested by means of redundancy analysis (RDA) and generalized linear mixed models (GLMM) in relation to the recorded environmental factors (BT: bottom temperature, BS: bottom salinity, OM: organic matter and granulometry (Phi)). The most influent environmental factor over the species distribution was the Phi, and the ascendant order of influence was P. lichtensteinii, P. punctata and P. mediterranea. The greater abundance of P. mediterranea showed a conservative pattern of distribution for the genus in the sampled region. The greater occurrence of P. punctata and P. lichtensteinii, in distinct transects than those occupied by P. mediterranea, seems to be a strategy to avoid competition among congeneric species, which is related to the substratum specificity.

Annual, seasonal and spatial abundance of the seabob shrimp Xiphopenaeus kroyeri (Decapoda, Penaeidae) off the Southeastern coast of Brazil

We investigated the influence of environmental factors in spatial and temporal distribution of the seabob shrimp Xiphopenaeus kroyeri in Santos Bay and São Vicente Estuary, state of São Paulo, Brazil. Monthly samples were obtained, from May 2008 through April 2010, from four locations in the estuary and four in the bay. No individual was collected in the estuary and this was attributed to the low salinity means recorded in this environment. We collected 109,153 individuals in the bay and there was no difference in abundance between the two years comprised by the study period. The similarity in spatial distribution can be related to sediment grain size that in all sampling locations showed great amount of very fine sand. The largest amount of reproductive females was obtained in early 2010, when temperature was high, and this could have increased the juvenile recruitment in April 2010. According to our results, the distribution of X. kroyeri in the study area is influenced by temperature, which is related to reproduction, and salinity, limiting the entrance of individuals in the estuarine region.

Slipper lobsters (Scyllaridae) off the southeastern coast of Brazil: relative growth, population structure, and reproductive biology

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Population ecology of the planktonic shrimp lucifer faxoni borradaile, 1915 (crustacea, sergestoidea, luciferidae) of the southeastern coast of brazil

Luciferid shrimps have short life spans and a rapid turnover of generations, engage in sequential spawning, and protect their eggs during incubation. This study investigates the ecology of Lucifer faxoni Borradaile, 1915 in the littoral zone, Ubatuba region, São Paulo. Sampling was conducted monthly from July 2005 to December 2006 using a Renfro net trawled over a distance of 50 m for a total sampling effort of 50 m² at each station. Nine stations were sampled, ranging from 1 to 15 m deep. Three stations each were grouped into zones 1, 2 and 3 (Z1, Z2 and Z3). Monthly values of salinity, temperature and rainfall were recorded at each station. The pre-buccal somite length (SL) of each specimen was measured. The results showed that in shallower zones (Z1 and Z2), 6306 individuals were captured, whereas in the deeper zone (Z3), 3808 specimens were captured, but no significant differences in SL was detected between the specimens from Z1 and Z2 and those from Z3 (ANOVA, p=0.25). The abundance of shrimps did not differ significantly between seasons (Tukey’s test, p=0.02) except in the spring. The sex ratio differed significantly over the seasons (χ², p<0.05). The results were closely associated with environmental factors with respect to the spatial and seasonal distribution of L. faxoni. Rainfall affected salinity directly, and contributed to the displacement of these shrimps to deeper areas.

Cetacean Notes. I. Sei and Rorqual Whales on the Mississippi Coast, a Correction. II. A Dwarf Sperm Whale in Mississippi Sound and Its Helminth Parasites

I. Gunter and Christmas (1973) described the events leading to the stranding of a baleen whale on Ship Island, Mississippi, in 1968, giving the species as Balaenopteru physalus, the Rorqual. Unfortunately the identification was in error, but fortunately good photographs were shown. The underside of the tail was a splotched white, but there was no black margin. The specimen also had fewer throat and belly grooves than the Rorqual, as a comparison with True’s (1904) photograph shows. Dr. James Mead (in litt.) pointed out that the animal was a Sei Whale, Balaenoptera borealis. This remains a new Mississippi record and according to Lowery’s (1974) count, it is the fifth specimen reported from the Gulf of Mexico. The stranding of a sixth Sei Whale on Anclote Keys in the Gulf, west of Tarpon Springs, Florida on 30 May 1974, was reported in the newspapers and by the Smithsonian Institution (1974). II. Gunter, Hubbs and Beal (1955) gave measurements on a Pygmy Sperm Whale, Kogia breviceps, which stranded on Mustang Island on the Texas coast and commented upon the recorded variations of proportional measurements in this species. Then according to Raun, Hoese and Moseley (1970) these questions were resolved by Handley (1966), who showed that a second species, Kogia simus, the Dwarf Sperm Whale, is also present in the western North Atlantic. Handley’s argument is based on skull comparisons and it seems to be rather indubitable. According to Raun et al. (op. cit.), the stranding of a species of Kogia on Galveston Island recorded by Caldwell, Ingles and Siebenaler (1960) was K. simus. They also say that Caldwell (in litt.) had previously come to the same conclusion. Caldwell et al. also recorded another specimen from Destin, Florida, which is now considered to have been a specimen of simus. The known status of these two little sperm whales in the Gulf is summarized by Lowery (op. cit.).

Observations on a Cyclic Decline of Lemmings (Lemmus) on the Arctic Coast of Alaska during the Spring of 1949

The importance to the biotic community of various species of lemmings in arctic and subarctic regions has long been recognized, but there is little known about the ecology of these mammals. of the two species that occur on the Arctic Slope of Alaska, namely, the collared lemming, Dicrostonyx groenlandicus rubricatus (Richardson), and the brown lemming, Lemmus trimucronatus alascensis Merriam, during the spring of 1949 the writer had the good fortune to observe a cyclic decline in the population of the brown lemming on the Arctic Coast of Alaska. Observations were made during the peak density preceding this decline and were continued for more than a year subsequent to it. It is the purpose of this paper to present the results of these studies.