30 research outputs found
Distribution and abundance of the argentinean (Artemesia longinaris) and the red prawns (Pleoticus muelleri) (Decapoda:Penaeoidea) in Southern Brazil during the commercial double-rig trawl fishery season
Declining in landings of more valuable prawn species, such as pink prawns(Farfantepenaeus paulensis and F. brasiliensis), expanded the targets of double-rig ottertrawlers to other species such as Artemesia longinaris and Pleoticus muelleri. In attempting to increase information on distribution and abundance of these prawns, 64 samples
were analyzed in summer/2005 during the commercial trawling fishery season off Rio
Grande do Sul coast. Samples were collected from a research vessel (NOc. Atlântico Sul – FURG) in depths varying between 5 and 29 as a contribution to SALVAR project. Temperature, salinity and substrate play an important role on distribution of A. longinaris, concentrating greater densities in areas of low temperature and high
salinity, associated to summer upwelling. Pleoticus muelleri showed a more homogenous
distribution and did not avoid areas of lower salinity under the influence of estuarine runoff. By using a swept area method, a total of 3369 tons of A. longinaris was estimated between isobaths of 10 and 20 meters. Pleoticus muelleri presented lower abundances and a total of 2527 tons was estimated by using the swept area method. Size distribution indicated that larger individuals of both species are located especially between 15 and 20. However, large individuals of A. longinaris clearly avoided the areas of lower salinity,
suggesting that spawning takes place outside the direct influence of Patos Lagoon estuary.
Conversely, P. muelleri takes advantage of lower salinity areas, avoided by A. longinaris, for spawning
Distribution and abundance of the argentinean (Artemesia longinaris) and the red prawns (Pleoticus muelleri) (Decapoda:Penaeoidea) in Southern Brazil during the commercial double-rig trawl fishery season
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Distribution and abundance of the argentinean (Artemesia longinaris) and the red prawns Pleoticus muelleri DECAPODA PENAEOIDEA in Southern Brazil during the commercial double-rig trawl fishery season.pdf: 1926009 bytes, checksum: 04becc8491ae3f1b7b6bdf9d8b99fa82 (MD5)Approved for entry into archive by Sabrina Andrade([email protected]) on 2012-06-28T20:11:18Z (GMT) No. of bitstreams: 1
Distribution and abundance of the argentinean (Artemesia longinaris) and the red prawns Pleoticus muelleri DECAPODA PENAEOIDEA in Southern Brazil during the commercial double-rig trawl fishery season.pdf: 1926009 bytes, checksum: 04becc8491ae3f1b7b6bdf9d8b99fa82 (MD5)Made available in DSpace on 2012-06-28T20:11:18Z (GMT). No. of bitstreams: 1
Distribution and abundance of the argentinean (Artemesia longinaris) and the red prawns Pleoticus muelleri DECAPODA PENAEOIDEA in Southern Brazil during the commercial double-rig trawl fishery season.pdf: 1926009 bytes, checksum: 04becc8491ae3f1b7b6bdf9d8b99fa82 (MD5)
Previous issue date: 2008Declining in landings of more valuable prawn species, such as pink prawns(Farfantepenaeus paulensis and F. brasiliensis), expanded the targets of double-rig ottertrawlers to other species such as Artemesia longinaris and Pleoticus muelleri. In attempting to increase information on distribution and abundance of these prawns, 64 samples
were analyzed in summer/2005 during the commercial trawling fishery season off Rio
Grande do Sul coast. Samples were collected from a research vessel (NOc. Atlântico Sul – FURG) in depths varying between 5 and 29 as a contribution to SALVAR project. Temperature, salinity and substrate play an important role on distribution of A. longinaris, concentrating greater densities in areas of low temperature and high
salinity, associated to summer upwelling. Pleoticus muelleri showed a more homogenous
distribution and did not avoid areas of lower salinity under the influence of estuarine runoff. By using a swept area method, a total of 3369 tons of A. longinaris was estimated between isobaths of 10 and 20 meters. Pleoticus muelleri presented lower abundances and a total of 2527 tons was estimated by using the swept area method. Size distribution indicated that larger individuals of both species are located especially between 15 and 20. However, large individuals of A. longinaris clearly avoided the areas of lower salinity,
suggesting that spawning takes place outside the direct influence of Patos Lagoon estuary.
Conversely, P. muelleri takes advantage of lower salinity areas, avoided by A. longinaris, for spawning
Growth and reproductive pattern of the caridean shrimp Palaemonetes argentinus (Decapoda:Caridea) in southern Brazil
In crustaceans, due to the absence of permanent hard parts which can be used for age determination, methods on length frequency distribuitions (e.g., Modal progression Analysis - MPA) are commonly employed for ageing. However, the linkage of the coborts followed during a period of time, brings uncertainty to the analysis. The present study suggests inclusion of biological aspects to validate the parameters estimatcd by the von Bertalanffy growth model (VBGM). The population of Palaemonetes argentinus analyzed here inhabits a closed lagoon near the Patos Lagoon (Lagoa dos Patos) estuary. Sample were collected fortnightly from june/1996 to December/1997 and carapace growth was estimated by using the VBGM. Biological aspects such as reproductive season, sex ratio and maximun carapace lengh were used to validate VBGM parameters. The growth paramets estimated were L=8.00 K=0.29/month; =0,34 for females and L= 6.67; K=0.34/month; =0.38 for males. The main reproductive season is spring, and brooding females were observed along the year, except on june-july/1996 and May-June/1997. The mean size of first maturity estimated was 6.5 (CL-mm). The validation of the VBGM parameters by using biological aspects has showed choerent results, reducing the uncertainty in choosing the modal groups that really describe the individual growth of the species
Est\ue1gios de desenvolvimento gonadal de f\ueameas do camar\ue3o-barba-ru\ue7a (Artemesia longinaris - Decapoda: Penaeidae)
Evolução da pescaria industrial de camarão-rosa (Farfantepenaeus brasiliensis e F. paulensis) na costa sudeste e sul do Brasil - 1968-1989
Foi analisada a série histórica de dados referentes à frota de arrasteiros de camarão-rosa do Estado de São Paulo para o perÃodo de 1968 a 1989, obtidos pelo Instituto de Pesca/SP. Este perÃodo foi separado em quatro qüinqüênios (1968-1972; 1973-1977; 1978-1983; 1984-1989) que identificam as diversas fases que caracterizaram a evolução da pescaria com base nos trabalhos de avaliação pesqueira. Uma clara mudança no padrão da pescaria foi observada ao longo dos qüinqüênios analisados. No primeiro perÃodo, a elevada CPUE das espécies-alvo sustentava bons rendimentos para a pescaria. Durante esse perÃodo, a pesca se distribuiu homogeneamente ao longo da costa do SE/S do Brasil, apresentando esforço de pesca bem distribuÃdo latitudinalmente e concentrado nas profundidades de maior abundância do camarão-rosa (40-80 m). A partir do segundo qüinqüênio, as capturas começam a se concentrar na região central, ainda na faixa de profundidade preferencial do camarão-rosa. Nessa fase da pescaria, é notável a diminuição da abundância relativa ao longo de toda área, reflexo do aumento do esforço de pesca aplicado sobre o estoque, embora os desembarques ainda tenham mantido um nÃvel considerado alto. O terceiro e quarto perÃodos são caracterizados pela queda na CPUE do estoque. A partir do terceiro qüinqüênio, a frota de arrasteiros passou a buscar novos recursos demersais, ampliando a sua área de atuação para profundidades que não mais refletem a distribuição do camarão-rosa. Como conseqüência dessa mudança no padrão de pesca, outras espécies passaram a ganhar importância nos desembarques, com o esforço migrando para profundidades maioresLong-term data obtained from São Paulo commercial pink shrimp fishery (Instituto de Pesca/SP) was analyzed from 1968-1989. Time series was divided in four different periods (1968-1972; 1973-1977; 1978-1983; 1984-1989), according to the trends observed in fishery assessment. A marked shift in fishery pattern was noticed along the different periods studied. During the first period, the high CPUE values of target species sustained highest yields of the entire period analyzed. The first period was characterized by a widespread distribution of fishing effort off SE/S Brazilian coast, concentrated within the depth range of highest abundance of pink shrimp (40-80 m). From the second period onwards, a concentration of catches in the central area was observed, even though within the depth distribution of the pink shrimp. During this phase, a marked decrease in relative abundance was noticed all over the distribution area, as a consequence of the increased fishing effort applied. The third and fourth periods were characterized by the low CPUE values. From the third period onwards, trawling fleet began to search for new demersal resources, migrating to the fishing grounds outside pink shrimp distribution area. As a consequence of this shift in the fishery pattern, other species started to became important in the land statistics, and the fishing effort moved offshor
Padrão reprodutivo, tamanho de primeira maturação e relações estoque/recrutamento do camarão-barba-ruça Artemesia longinaris no sul do Brasil
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Previous issue date: 2011Artemesia longinaris tem sido recentemente explorado pela pesca artesanal e industrial no Sul do Brasil. Para investigar a biologia reprodutiva desta espécie no Sul do Brasil, amostras mensais, entre as profundidades de 5 e 20 metros, foram analisadas entre Fevereiro/2002 e Janeiro/2003. Relações entre estoque desovante e recrutamento (RER) foram estimadas, assim como um modelo preliminar para previsão de biomassa. O esforço reprodutivo está concentrado na primavera, entretanto, foi observado um recrutamento contÃnuo ao longo do ano. A reprodução durante o outono é mais variável e susceptÃvel a chuvas intensas e consequentemente menores salinidades observadas na área de estudo. Uma migração reprodutiva, para profundidades em torno dos 15 metros, foi observada e o recrutamento inicia aproximadamente 1 mês após a desova. O tamanho médio de primeira maturação foi estimado em 16,76 mm e é atingido em aproximadamente 4 meses. Um ajuste significativo dos dados aos modelos de estoque-recrutamento (RER) foi obtido sob condições ambientais adversas, sugerindo que a redução do estoque desovante possa resultar em uma sobrepesca de recrutamento. Um modelo preliminar de previsão de abundância foi desenvolvido e o fator de maior influência no recrutamento foi a salinidade durante a principal temporada de desova (primavera). Já para os anos de condições ambientais desfavoráveis, o principal fator foi a biomassa do estoque desovante, enquanto que em anos de condições favoráveis a salinidade foi o principal fator.Artemesia longinaris has been recently exploited by commercial and artisanal fisheries in Southern Brazil. To investigate the reproductive biology of this species, monthly samples were analyzed between February/2002 and January/2003, in depths between 5 and 20 meters in surrounding area of the Barra do Rio Grande. Stock-recruitment relationships (SRR) were estimated, as well as a preliminary predictive model for recruit biomass. Reproductive effort is concentrated in spring; however, recruitment was observed year round. Reproduction in autumn is more variable, and susceptible to intense rainfall and consequent low salinity observed in the studied area. A reproductive migration to depths farther than 15 meters was observed, and recruitment in shallower waters starts approximately one month after hatching. Mean length at first maturity was estimatedin 16.76 mm and is achieved in approximately 4 months. Significant fit of stock-recruitment relationships (SRR) was observed for three models tested under adverse environmental conditions, suggesting that the reduction of spawning biomass combined with unfavorable environmental conditions may lead to recruitment overfishing. A preliminary predictive model was developed and the main factor influencing recruitment of the species is salinity in spawning season. The main factor influencing recruitment success under adverse environmental conditions is the biomass of spawning stock, while under favorable conditions salinity in spawning season plays a significant role
Reproductive pattern, size at first maturity and stock-recruitment relationships of the argentine stiletto shrimp (Artemesia longinaris, Decapoda, Penaeidae) in southern Brazil
Artemesia longinaris tem sido recentemente explorado pela pesca artesanal e industrial no Sul do Brasil. Para investigar a biologia reprodutiva desta espécie no Sul do Brasil, amostras mensais, entre as profundidades de 5 e 20 metros, foram analisadas entre Fevereiro/2002 e Janeiro/2003. Relações entre estoque desovante e recrutamento (RER) foram estimadas, assim como um modelo preliminar para previsão de biomassa. O esforço reprodutivo está concentrado na primavera, entretanto, foi observado um recrutamento contÃnuo ao longo do ano. A reprodução durante o outono é mais variável e susceptÃvel a chuvas intensas e consequentemente menores salinidades observadas na área de estudo. Uma migração reprodutiva, para profundidades em torno dos 15 metros, foi observada e o recrutamento inicia aproximadamente 1 mês após a desova. O tamanho médio de primeira maturação foi estimado em 16,76 mm e é atingido em aproximadamente 4 meses. Um ajuste significativo dos dados aos modelos de estoque-recrutamento (RER) foi obtido sob condições ambientais adversas, sugerindo que a redução do estoque desovante possa resultar em uma sobrepesca de recrutamento. Um modelo preliminar de previsão de abundância foi desenvolvido e o fator de maior influência no recrutamento foi a salinidade durante a principal temporada de desova (primavera). Já para os anos de condições ambientais desfavoráveis, o principal fator foi a biomassa do estoque desovante, enquanto que em anos de condições favoráveis a salinidade foi o principal fator.Artemesia longinaris has been recently exploited by commercial and artisanal fisheries in Southern Brazil. To investigate the reproductive biology of this species, monthly samples were analyzed between February/2002 and January/2003, in depths between 5 and 20 meters in surrounding area of the Barra do Rio Grande. Stock-recruitment relationships (SRR) were estimated, as well as a preliminary predictive model for recruit biomass. Reproductive effort is concentrated in spring; however, recruitment was observed year round. Reproduction in autumn is more variable, and susceptible to intense rainfall and consequent low salinity observed in the studied area. A reproductive migration to depths farther than 15 meters was observed, and recruitment in shallower waters starts approximately one month after hatching. Mean length at first maturity was estimatedin 16.76 mm and is achieved in approximately 4 months. Significant fit of stock-recruitment relationships (SRR) was observed for three models tested under adverse environmental conditions, suggesting that the reduction of spawning biomass combined with unfavorable environmental conditions may lead to recruitment overfishing. A preliminary predictive model was developed and the main factor influencing recruitment of the species is salinity in spawning season. The main factor influencing recruitment success under adverse environmental conditions is the biomass of spawning stock, while under favorable conditions salinity in spawning season plays a significant role
The mtdna control region of the barba-ruça shrimp artemesia longinaris (decapoda:penaeidae) and Its potential use as a marker for population analysis
O camarão Artemesia longinaris é endêmico do Atlântico Sudoeste, sendo explorado comercialmente desde a Argentina (Puerto Rawson – 21o37’S) até o Sudeste do Brasil (Rio de Janeiro – 43o00’S). Marcadores moleculares, tais como a região controle do mtDNA (RC), tem sido usados para elucidar a estrutura filogeográfica de camarões peneÃdeos ao redor do mundo. A região controle do mtDNA foi testada como marcador molecular para estudos populacionais, na intenção de desenvolver um novo conjunto de primers para amplificar essa região. Os primers foram posicionados nos genes flanqueando a região controle, que apresentaram a mesma ordem reportada para outros peneÃdeos (12S no extremo 5’ e tRNAIle3 no extremo 3’). A RC de A. longinaris apresentou um tamanho de 990 pb, incluindo duas regiões hipervariáveis nos extremos 5’ e 3, com uma região central menos polimórfica. Adicionalmente, um primer interno, desenhado para amplificar aproximadamente 800 pb, da extremidade 5’ da região controle, incluindo a região hipervariável I, foi desenvolvido para estudos de estrutura populacional. A comparação das seqüências da região controle com as da COI demonstrou que a primeira apresenta maior grau de polimorfismo. A diversidade nucleotÃdica estimada para a região controle foi baixa (_=0,017) e a diversidade haplotÃpica alta (Hd=0,92), mas ambas caem dentro do limite sugerido para a famÃlia. Valores preliminares de Fst sugerem que populações habitando os extremos da distribuição apresentam menor intercâmbio genético. Em resumo, o trabalho confirma a utilidade da região hipervariável I, incluÃda na região controle, como um marcador molecular para resolver a estrutura das populações de A. longinaris.The shrimp Artemesia longinaris is endemic from Southwestern Atlantic and is commercially exploited from Argentina (Puerto Rawson – 21o37’S) to Southeastern Brazil (Rio de Janeiro – 43º 00’S). Molecular markers, such as the mtDNA control region, (CR) have been used to elucidate the population structure of penaeid shrimps worldwide. The suitability of mtDNA CR of the barba-ruça shrimp as a molecular marker at a population level was tested and a novel set of primers to amplify this region has been designed. Primers were rooted in the flanking genes of the CR that showed the same order (12S at 5’ and tRNAIle3 at 3’ extreme) as reported for other penaeid shrimps. The CR of A. longinaris was 990 bp long, presenting two hypervariable regions at the 5’ and 3’ extremes (more variable), and a central one with less polymorphism. In addition, an internal primer set to amplify approximately 800 bp of 5’ extreme of CR, including the hypervariable region I, is provided to help resolving population structure. Comparison of the CR with cytochrome oxydase I (COI) sequences showed that the former gene presents higher polymorphism. Nucleotide diversity estimated for CR was low (_=0.017), and haplotype diversity high (Hd=0.92), but both fall within the values suggested for the family. Preliminary Fst values suggest that populations inhabiting extremes of distribution show less genetic interchange. Briefly, we were able to confirm the suitability of CR hypervariable regions of A. longinaris as a molecular marker to resolve the population structure of A. longinaris. identification
Stages of gonadal development and mean length at first maturity of wild females of white shrimp (litopenaeus schmitti – decapoda, penaeidae) in southern Brazil
Os estágios de desenvolvimento das gônadas das fêmeas do camarão-branco (Litopenaeus schmitti (Burkenroad,1936)) foram caracterizadas por análise histológica. Quatro estágios (imaturo, em desenvolvimento, maduro e desovado) foram determinados de acordo a estrutura e arranjo das células no ovário. Cada estágio corresponde, microscopicamente, a uma cor caracterÃstica, exceto nos estágios I (imaturo) e IV (desovado) nos quais as cores são muito similares e podem ser distinguidas apenas histologicamente. A escala cromática varia do branco/translúcido (estágio I), cinza/verde (em desenvolvimento), verde escuro a preto (maduro). O tamanho médio das células foi 54,01 μm (±3,5) (estagio I), 136,80 μm (±8,8) (estágio II) e 199,80 μm (±6,4) (estágio III). A distribuição de frequência do tamanho das células foi polimodal, e diferentes estágios celulares foram observados nos ovários maduros, sugerindo a ocorrência de desovas múltiplas. A menor fêmea madura mediu 152 mm e o comprimento em que 100% das fêmeas estavam maduras foi 170 mm.The stages of gonadal development for the female of white shrimp (Litopenaeus schmitti (Burkenroad, 1936)) were characterized based on histological analysis. Four stages (immature, developing, ripe and spawned) were determined according to the structure and arrangement of cells in the ovary. Each stage corresponds macroscopically to a characteristic color, except stages I (immature) and IV (spawned), in which colors are very similar and can be distinguished only microscopically. The chromatic scale varies from white/translucent (stage I), gray/green (developing), dark green to black (ripe). The mean size of cells was 54.01 μm (±3.5) (stage I), 136.80 μm (±8.8) (stage II) and 199.80 μm (±6.4) (stage III). The size frequency of cells was polymodal, and different cell stages were observed in ripe ovary, suggesting the occurrence of multiple spawning. The smallest ripe female measured 146 mm and the largest 180 mm of the total length. Estimated mean length at first maturity was 152 mm and the length at which 100% of females are mature is 170 mm