Lopes C.M.,Federal University of Rio Grande do Sul |
Ximenes S.S.F.,Federal University of Rio Grande do Sul |
Gava A.,Federal Foundation University of Rio Grande |
De Freitas T.R.O.,Federal University of Rio Grande do Sul
Heredity | Year: 2013
Identifying factors and the extent of their roles in the differentiation of populations is of great importance for understanding the evolutionary process in which a species is involved. Ctenomys minutus is a highly karyotype-polymorphic subterranean rodent, with diploid numbers ranging from 42 to 50 and autosomal arm numbers (ANs) ranging from 68 to 80, comprising a total of 45 karyotypes described so far. This species inhabits the southern Brazilian coastal plain, which has a complex geological history, with several potential geographical barriers acting on different time scales. We assessed the geographical genetic structure of C. minutus, examining 340 individuals over the entire distributional range and using information from chromosomal rearrangements, mitochondrial DNA (mtDNA) sequences and 14 microsatellite loci. The mtDNA results revealed seven main haplogroups, with the most recent common ancestors dating from the Pleistocene, whereas clustering methods defined 12 populations. Some boundaries of mtDNA haplogroups and population clusters can be associated with potential geographical barriers to gene flow. The isolation-by-distance pattern also has an important role in fine-scale genetic differentiation, which is strengthened by the narrowness of the coastal plain and by common features of subterranean rodents (that is, small fragmented populations and low dispersal rates), which limit gene flow among populations. A step-by-step mechanism of chromosomal evolution can be suggested for this species, mainly associated with the metapopulation structure, genetic drift and the geographical features of the southern Brazilian coastal plain. However, chromosomal variations have no or very little role in the diversification of C. minutus populations. © 2013 Macmillan Publishers Limited All rights reserved.
Amorim F.N.,University of Sao Paulo |
Cirano M.,Federal University of Bahia |
Soares I.D.,Federal Foundation University of Rio Grande |
Lentini C.A.D.,Federal University of Bahia
Continental Shelf Research | Year: 2011
The Camamu Bay (CMB) is located on the narrowest shelf along the South American coastline and close to the formation of two major Western Boundary Currents (WBC), the Brazil/North Brazil Current (BC/NBC). These WBC flow close to the shelf break/slope region and are expected to interact with the shelf currents due to the narrowness of the shelf. The shelf circulation is investigated in terms of current variability based on an original data set covering the 2002-2003 austral summer and the 2003 austral autumn. The Results show that the currents at the shelf are mainly wind driven, experiencing a complete reversal between seasons due to a similar change in the wind field. Currents at the inner-shelf have a polarized nature, with the alongshore velocity mostly driven by forcings at the sub-inertial frequency band and the cross-shore velocity mainly supra-inertially forced, with the tidal currents playing an important role at this direction. The contribution of the forcing mechanisms at the mid-shelf changes between seasons. During the summer, forcings in the two frequency bands are important to drive the currents with a similar contribution of the tidal currents. On the other hand, during the autumn season, the alongshore velocity is mostly driven by sub-inertial forcings and tidally driven currents still remain important in both directions. Moreover, during the autumn when the stratification is weaker, the response of the shelf currents to the wind forcing presents a barotropic signature. The meso-scale processes related to the WBC flowing at the shelf/slope region also affect the circulation within the shelf, which contribute to cause significant current reversals during the autumn season. Currents at the shelf-estuary connection are clearly supra-inertially forced with the tidal currents playing a key role in the generation of the along-channel velocities. The sub-inertial forcings at this location act mainly to drive the weak ebb currents which were highly correlated with both local and remote wind forcing during the summer season. © 2010 Elsevier Ltd.
Ballester E.L.C.,Federal Foundation University of Rio Grande |
Abreu P.C.,Federal Foundation University of Rio Grande |
Cavalli R.O.,Federal Rural University of Pernambuco |
Emerenciano M.,Federal Foundation University of Rio Grande |
And 2 more authors.
Aquaculture Nutrition | Year: 2010
Farfantepenaeus paulensis juveniles (72 ± 24 mg), were reared in a suspended microbial flocs system and fed practical diets containing increasing amounts of crude protein (250, 300, 350, 400 and 450 g kg-1 CP). Development of microbial flocs was promoted by high aeration rates and fertilization with wheat bran and molasses. Flocs were composed of detritus in the form of flocculated matter colonized by heterotrophic bacteria, cocoid and filamentous cyanobacteria, flagellate and ciliate protozoa and rotifers. Proximate composition analysis of the suspended microbial floc showed CP levels of 304 g kg-1. After 45 days, mean shrimp survival were above 89%, with no significant differences between treatments. Shrimp fed diets with 350 g kg-1 or higher CP content achieved significant higher (P < 0.05) final weight (0.66-0.68 g), weight gain (0.58-0.61 g) and instantaneous growth rate (0.049-0.050), with feed conversion rates (2.17-2.30) significantly lower (P < 0.05). Results show that, when rearing is carried out in a suspended microbial flocs system, dietary CP levels can be kept at 350 g kg-1. Furthermore, results confirm that microbial-based systems allow shrimp culture without compromising the surrounding environment and shows the possible reduction of production costs and fish meal dependence. © 2009 Blackwell Publishing Ltd.
De Lima F.D.,Federal University of Rio Grande do Norte |
Leite T.S.,Federal University of Rio Grande do Norte |
Haimovici M.,Federal Foundation University of Rio Grande |
Lins Oliveira J.E.,Federal University of Rio Grande do Norte
Hydrobiologia | Year: 2014
Octopus insularis inhabits shallow waters along the coast and oceanic islands of northeastern Brazil, where it is the main target of commercial fishing of octopuses. This study aims to investigate the hypothesis that the tropical O. insularis has a distinct gonadal development and reproductive features when compare to its congener O. vulgaris from the subtropical regions. In order to describe its reproductive development, 545 octopuses were collected in the Northeastern Brazil. A good correspondence was observed between the gonad morphology and its histological structure. Oocytes in different development stages were observed in mature females. Most female in early maturity stages had sperm stored in the spermathecae, indicating that females copulate when still immature. There was no correlation between testis weight and the Needham complex, suggesting a protracted period of spermatophore production. Octopus insularis has a general gonadal development pattern similar to O. vulgaris, however, some differences were observed, as maturation at a smaller size, probably associated to a shorter life, and lower fecundity. The distinct reproductive features of O. insularis seem to be related to less variable conditions in the tropical environments. Management should take into account the differences and establish specific rules for the Northeast Brazil octopus fisheries. © 2013 Springer Science+Business Media Dordrecht.
Avigliano E.,University of Buenos Aires |
Velasco G.,Federal Foundation University of Rio Grande |
Volpedo A.V.,University of Buenos Aires
Environmental Biology of Fishes | Year: 2015
The marine catfish Genidens barbus is an anadromous species from South America. The aim of the present study was to evaluate the use of lapillus otolith microchemistry (Sr:Ca; Ba:Ca and Mg:Ca ratios) as an indicator of changes in habitat use and identify the potential breeding areas and fish stocks of G. barbus populations from the Plata Basin (Paraná River Delta and De la Plata River estuary-Argentina) and Lagoa dos Patos coastal lagoon (southern Brazil). Sr:Ca, Ba:Ca and Mg:Ca ratios were measured in the core area (inner 4 rings) and external area (outer 3–4 rings) of the otoliths by ICP-OES. The Sr:Ca ratio tended to be higher in the otolith external area than in the core area, while the Ba:Ca ratio followed the opposite pattern. This suggests the displacement of fish toward higher salinity areas. The Sr:Ca, Ba:Ca, Mg:Ca ratios in the core and external areas of the otoliths from the Plata Basin differed significantly from those of the otoliths from Lagoa dos Patos. This may indicate the occurrence of two different breeding sites and at least two fish stocks in the study region. © 2015, Springer Science+Business Media Dordrecht.
Muelbert M.M.C.,Federal Foundation University of Rio Grande |
de Souza R.B.,National Institute for Space Research |
Lewis M.N.,CONICET |
Hindell M.A.,University of Tasmania
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2013
Elephant Island (EI) is uniquely placed to provide southern elephant seals (SES) breeding there with potential access to foraging grounds in the Weddell Sea, the frontal zones of the South Atlantic Ocean, the Patagonian shelf and the Western Antarctic Peninsula (WAP). Quantifying where seals from EI forage therefore provides insights into the types of important habitats available, and which are of particular importance to elephant seals. Twenty nine SES (5 sub-adult males-SAM and 24 adult females-AF) were equipped with SMRU CTD-SLDRs during the post-breeding (PB 2008, 2009) and post-moulting (PM 2007, 2008, 2009, 2010) trips to sea. There were striking intra-annual and inter-sex differences in foraging areas, with most of the PB females remaining within 150. km of EI. One PB AF travelled down the WAP as did 16 out of the 20 PM females and foraged near the winter ice-edge. Most PM sub-adult males remained close to EI, in areas similar to those used by adult females several months earlier, although one SAM spent the early part of the winter foraging on the Patagonian Shelf. The waters of the Northern Antarctic Peninsula (NAP) contain abundant resources to support the majority of the Islands' SES for the summer and early winter, such that the animals from this population have shorter migrations than those from most other populations. Sub-adult males and PB females are certainly taking advantage of these resources. However, PM females did not remain there over the winter months, instead they used the same waters at the ice-edge in the southern WAP that females from both King George Island and South Georgia used. Females made more benthic dives than sub-adult males-again this contrasts with other sites where SAMs do more benthic diving. Unlike most other populations studied to date EI is a relatively southerly breeding colony located on the Antarctic continental shelf. EI seals are using shelf habitats more than other SES populations but some individuals still employ open water foraging strategies. Sea-ice was also very influential for PM females with more foraging occurring in heavier pack-ice. Larger females used areas with heavier ice-concentration than smaller females. The study demonstrates the importance of shelf and slope habitat to elephant seals, but also highlighted the influence of sea-ice and fine-scale bathymetry and local ocean condition in determining foraging habitat. © 2012 Elsevier Ltd.
Huong D.T.,Vietnam Academy of Science and Technology |
Hue L.T.,Vietnam Academy of Science and Technology |
Rodriguez M.C.,Federal Foundation University of Rio Grande |
Long H.N.,Vietnam Academy of Science and Technology
Nuclear Physics B | Year: 2013
We build a supersymmetric version of the minimal 3-3-1 model with just two Higgs triplets using the superfield formalism. We study the mass spectrum of all particles in concordance with the experimental bounds. At the tree level, the masses of charged gauge bosons are the same as those of charged Higgs bosons. We also show that the electron, muon and their neutrinos as well as down and strange quarks gain mass through the loop correction. The narrow constraint on the ratio tw=ww' is given by studying the new invisible decay mode of the Z boson. © 2013 Elsevier B.V.
Peixoto S.,University of Pernambuco |
Wasielesky W.,Federal Foundation University of Rio Grande |
Cavalli R.O.,University of Pernambuco
Aquaculture | Year: 2011
The interest in culturing indigenous penaeid species has increased lately due to Litopenaeus vannamei disease outbreaks, especially in southern Brazil. Although sustainable production of the pink shrimp Farfantepenaeus paulensis is greatly desired, it has been constrained by the current dependency on wild-caught broodstock. To overcome this problem, research efforts have focused on the development of domesticated stocks and optimization of their reproductive performance under laboratory conditions. We present the latest developments on maturation and reproduction of this closed thelycum species, aiming to improve the future outlook for a sustainable nauplii production. © 2010 Elsevier B.V.
Martins C.C.,Federal University of Paraná |
Braun J.A.F.,Federal Foundation University of Rio Grande |
Seyffert B.H.,Federal Foundation University of Rio Grande |
Machado E.C.,Federal University of Paraná |
Fillmann G.,Federal Foundation University of Rio Grande
Marine Pollution Bulletin | Year: 2010
Urban sewage is considered one of the most important sources of marine pollution in South America, because most coastal cities do not have proper facilities to treat and dispose of sewage. The Paranaguá estuarine system is an important estuarine environment of the South American coast where fishing, urban and tourist activities, industries and the main Brazilian grain shipping port are potential sources of pollution in this area. The anthropogenic input of sedimentary organic matter, represented by sewage contribution, was evaluated by fecal steroid concentrations. The coprostanol levels were comparatively low (<0.10μgg-1), except at the sites close to Paranaguá city, where the coprostanol concentration reached 2.22μgg-1 showing strong sewage contamination. Fecal steroid levels were comparable to the lower to midrange concentrations reported for coastal sediments worldwide. The results of this work demonstrated that sewage pollution can be considered a problem for a small part of the Paranaguá estuary. © 2010 Elsevier Ltd.
Vidal E.A.G.,Federal University of Paraná |
Fuentes L.,Spanish Institute of Oceanography |
da Silva L.B.,Federal Foundation University of Rio Grande
Fisheries Research | Year: 2010
The chromatophore pattern of cephalopods provides a rapid and relatively easy means to identify species. Therefore, this paper describes and compares the morphology and chromatophore pattern of Octopus vulgaris paralarvae from different geographic regions, specifically, the notheastern (Galicia, Spain) and the southwestern (Southern Brazil), Atlantic, and ultimately, contributes to knowledge for future discrimination of populations of O. vulgaris from both regions. The eggs and paralarvae of both localities were incubated in the laboratory and reared at 21 and 22. °C from hatching to 17 or 45 days of age. Important differences were observed on the chromatophores pattern of paralarvae from both regions. In the ventral mantle, between 23 and 36 chromatophores were found in the Brazilian paralarvae, whereas between 16 and 20 were found in the Spanish paralarvae. However, Brazilian paralarvae showed considerably less extrategumental chromatophores over the viscera (6-9) in the dorsal mantle than the Spanish paralarvae (6-20). Differences were also detected in the funnel, 4-6 chromatophores (four different patterns) versus 4 (single pattern), respectively. These results showed substantial differences between the chromatophore patterns of paralarvae from both regions, which could provide evidence for the existence of distinct populations or even cryptic O. vulgaris-like species along the Southern Brazilian coast. © 2010 Elsevier B.V.