Navegando por Assunto "Bagre"

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Acesso aberto (Open Access)
Acordos de pesca: desafios de implementação e consolidação em áreas de várzea do município de Gurupá, Pará, Brasil
(Universidade Federal do Pará, 2010-08-03) COSTA, Pâmela Melo; MCGRATH, David Gibbs; http://lattes.cnpq.br/4373475491613670
Considering the context in which many decisions Amazon to protect and conserve the environment for the region often arise vertically, with no participation of the users of natural resources, local community in decision-making processes, and end up forgetting the empirical experiences this population is that they did this study. Through the methodological techniques: direct observation, application of semi-structured interviews, analysis of monitoring data sheets, we tried to look at the context of life gurupaense, especially those living on the floodplains of the municipality, and has considered agroextractivists activity fishing source of protein, income and who has been practicing in a shared mechanism of the Fisheries Agreement as a way of managing this activity. The research focuses on the Community Management of Shrimp implementation process and consolidate the participation of experts, NGOs and financing projects, as well as the social, economic and environmental conditions in periods in which there was or not the work of that outside mediation. The study showed that participation of outside mediation stimulated organizational processes and provided the local collective action, which even with the termination of support, self-management and community force is passed on to younger generations, but the study also shows that the challenge best indicators for the environmental levels is required technical support to promote scientific research in the field of Population Dynamics of Fish Stocks.
Acesso aberto (Open Access)
Aspectos ecológicos do bacu-pedra Lithodoras dorsalis (Valenciennes, 1840) (Siluriformes: Doradidae) na foz amazônica, Brasil
(Universidade Federal do Pará, 2012) BARBOSA, Thiago Augusto Pedroso; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The aim of this study was investigate the ecological aspects related to the rock-bacu Lithodoras dorsalis (Siluriformes: Doradidae) from streams next to the city of Abaetetuba, Pará, Brazil. The aspects investigated were: feeding ecology and dispersal of plant diaspores (seeds). The study of feeding ecology and seed dispersal are important because they provide essential information for understanding the relationship between ichthyofauna and environment, allowing the taking of effective measures in the conservation of species and ecosystems. The samplings were carried out monthly from July 2010 to June 2011. In this period, 371 specimens of L. dorsalis were collected and through analysis of the gonads was found that all were immature. The average standard length was equal to 15.40 cm (SD ± 4.87 cm) and average total mass equal to 94 g (SD ± 149.45). The diet of the species was composed by 28 food items (16 allochthonous origin and 12 autochthonous origin) and Lithodoras dorsalis was classified as herbivore with a strong tendency to frugivory due to the high importance of fruits and seeds in your diet. With regard to the intensity of obtaining food by the rock-bacu, there were differences between the pluviometric periods, where the end of the transitional period wet-drought and early drought periods represented the lowest and highest feeding activity, respectively. However, there were no significant difference to the importance of the items consumed between the pluviometric periods, the diet of species was similar throughout the sampling period. About the dispersal of seeds, 268 (74.93%) of 371s pecimens of Lithodoras dorsalis showed fruit and vegetable seeds in their stomachs, the main being the assai Euterpe oleracea Mart., the aninga Montrichardia linifera (Arruda) Schott and the buriti Mauritia flexuosa Mart. For analysis we used the assai seeds Euterpe oleracea Mart. and aninga Montrichardia linifera (Arruda) Schott for reaching enough samples. From the analysis of the digestive tract of the rock-bacu was found that all plant diaspores of Euterpe oleracea Mart. were found intact, with an increase in performance of this plant germination, but this did not occur to aninga Montrichardia linifera (Arruda) Schott, because the digestion process destroyed some seeds. Thus it was concluded that Lithodoras dorsalis is a potential disperser of assai Euterpe oleracea Mart. in the Amazonian mouth, because in addition to increasing the performance of the seeds germination, there is an increase in the amount of fruits and seeds consumed by the individuals with the increasing of their body size. Finally, given the high consumption of material of allochthonous origin for Lithodoras dorsalis, we highlight the importance of riparian vegetation by providing items such as fruit and seeds, essential in the diet of Neotropical fishes and we emphasize the importance of ictiocoria for plants since many have sessile habit of life and cannot move from one location to another without the aid of dispersers.
Acesso aberto (Open Access)
Early Pleistocene lineages of Bagre bagre (Linnaeus, 1766) (Siluriformes: Ariidae), from the Atlantic coast of South America, with insights into the demography and biogeography of the species
(Sociedade Brasileira de Ictiologia, 2016) SILVA, Wemerson Clayton da; MARCENIUK, Alexandre Pires; SALES, João Bráullio de Luna; SILVA, Juliana Araripe Gomes da
Coastal and marine environments are characterized by a lack of evident physical barriers or geographic isolation, and it may be difficult to understand how divergence can arise and be sustained in marine environments. The identification of 'soft' barriers is a crucial step towards the understanding of gene flow in marine environments. The marine catfishes of the family Ariidae are a demersal group with restricted migratory behavior, no pelagic larval stages, and mechanisms of larval retention, representing a potentially useful model for the understanding of historical processes of allopatric speciation in the marine environment. In the present study, two lineages of the Coco sea catfish, Bagre bagre , were recognized from their complete segregation at both mitochondrial and morphological levels. One lineage is distributed between Venezuela and the northern coast of Brazil, including the semiarid northeast coast, while the second lineage is found on the eastern coast of Brazil, including the humid northeast coast. Based on distribution area, habitats preference, and genetic variability, inferences are made in relation to biogeography and demography of lineages in Atlantic coast of South America.
Acesso aberto (Open Access)
Feeding ecology of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) in a riparian flooded forest of Eastern Amazonia, Brazil
(2011) FREITAS, Tiago Magalhães da Silva; ALMEIDA, Vitor Hudson da Consolação; VALENTE, Roberta de Melo; MONTAG, Luciano Fogaça de Assis
Feeding habits of the midnight catfish Auchenipterichthys longimanus collected in rivers of the Caxiuanã National Forest (Eastern Amazonia, Brazil) were investigated through the different hydrological periods (dry, filing, flood and drawdown). A total of 589 specimens were collected throughout seven samplings between July 2008 and July 2009, of which 74 were young males, 177 adult males, 89 young females and 249 adult females. The diet composition (Alimentary index – Ai%) was analyzed by a non-metric multidimensional scaling (nMDS) and by the analysis of similarity (ANOSIM), which included 37 items grouped into nine categories (Aquatic insects, Other aquatic invertebrates, Arthropods fragment, Fish, Plant fragment, Seeds, Terrestrial insects, Other terrestrial invertebrates, and Terrestrial vertebrates). We also calculated the niche breadth (Levins index) and the repletion index (RI%). Differences in the diet composition between hydrological seasons were registered, primarily on diet composition between dry and flood season, but changes related with sex and maturity were not observed. The midnight catfish showed more specialists feeder habit in the flood period (March 2009) and more generalist habits in the dry season (November 2008). The amount of food eaten by A. longimanus based on repletion index (RI%), did not differ significantly from sex and maturity. However, we evidenced differences in RI% when comparing the studied months. These results provide important biological information about the trophic ecology of auchenipterids fish. In view of the higher occurrence of allochthonous items, this research also underpins the importance of riparian forests as critical environments in the maintenance and conservation of wild populations of fish in the Amazon basin.
Acesso aberto (Open Access)
Infection by Henneguya sp. (Myxozoa) in the bone tissue of the gill filaments of the Amazonian catfish Hypophthalmus marginatus (Siluriformes)
(Universidade Federal do Pará, 2015-09) SILVA, Michele Velasco Oliveira da; VIDEIRA, Marcela Nunes; SINDEAUX NETO, José Ledamir; SANTOS, Patricia dos; SANCHES, Osimar de Carvalho; MATOS, Patrícia Santos
This study describes aspects of the infection caused by the myxosporean genus Henneguya, which forms cysts in the bony portion of the gill filaments of Hypophthalmusmarginatus. Specimens of this catfish were acquired dead from artisanal fishermen near the town of Cametá, state of Pará, northern Brazil, between July 2011 and May 2012. They were transported in refrigerated containers to the Carlos Azevedo Research Laboratory at the Federal Rural University of Amazonia, in Belém, where analyses were performed. After confirmation of parasitism by the genus Henneguya, observation were made using optical and differential interference contrast (DIC) microscopy. The histological technique of embedment in paraffin was used. Ziehl-Neelsen staining was applied to the histological sections. Necropsy analyses on specimens of H. marginatus showed that 80% of them (40/50) had cysts of whitish coloration inside the bony portion of the gill filaments, filled with Henneguya spores. The present study found inflammatory infiltrate in the vicinity of the cysts. Furthermore, the special Ziehl-Neelsen staining technique made it possible to mark the Henneguya sp. cysts in the bone tissue and in spore isolates in the gill tissue structure. The descriptions of these histopathological findings show that this parasite is very invasive and causes damage to its host tissues.
Acesso aberto (Open Access)
Influence of the flood pulse on the reproduction of Tocantinsia piresi (Miranda Ribeiro) and Auchenipterus nuchalis (Spix & Agassiz) (Auchenipteridae) of the middle Xingu River, Brazil
(Universidade Federal do Pará, 2015-08) FREITAS, Tiago Magalhães da Silva; PRUDENTE, Bruno da Silveira; OLIVEIRA, Valéria de Albuquerque; OLIVEIRA, Mairo Nazareno Carvalho de; PRATA, Erival Gonçalves; SOUSA, Híngara Leão; MONTAG, Luciano Fogaça de Assis
This study investigates the influence of the flood pulse on the reproductive biology of the auchenipterids Tocantisia piresi (Miranda Ribeiro, 1920) and Auchenipterus nuchalis (Spix & Agassiz, 1829) from the middle Xingu River in the Brazilian state of Pará. The specimens were collected every three months between April, 2012, and January, 2014, covering four distinct periods (flood, ebb, dry, and filling). The sex ratio, size at first maturity, gonadosomatic index, and condition factor were analysed in the two species, and evaluated in the context of the different hydrological periods. A total of 897 specimens of T. piresi were collected, of which 467 were female, and 430 males, and 383 A. nuchalis (286 females and 97 males). In T. piresi, the sex ratio was biased only in the filling and ebb periods, whereas in A. nuchalis, it departed significantly from the expected ratio of 1:1 in all periods, with a predominance of females. The female T. piresi mature at a smaller size than the males, with the opposite of the pattern being recorded in A. nuchalis. In T. piresi, the breeding peak was observed during the low water periods, whereas in A. nuchalis, the peak was recorded in the flood periods. Male and female T. piresi presented similar positively allometric growth rates, whereas in A. nuchalis, growth was negatively allometric, but rates were different between genders. A higher condition factor was recorded in the females of both species during the ebb period. Overall, the results of this study reveals distinct flood pulse effects on the reproductive parameters of the two auchenipterid species studied; for A. nuchalis the spawning seems to happen at the flood period and for T. piresi at the dry season of the middle Xingu River.
Acesso aberto (Open Access)
Kudoa spp. (Myxozoa, Multivalvulida) parasitizing fish caught in Aracaju, Sergipe, Brazil
(Universidade Federal do Pará, 2016-12) EIRAS, Jorge Costa; FUJIMOTO, Rodrigo Yudi; MADI, Rubens Riscala; JERALDO, Veronica de Lourdes Sierpe; MELO, Cláudia Moura de; SOUZA, Jônatas dos Santos de; DINIZ, José Antonio Picanço; DINIZ, Daniel Guerreiro
This study reports on Kudoa spp. (Myxozoa, Multivalvulida) from the fish species Lutjanus analis, Bagre marinus, Aspistor luniscutis and Lutjanus jocu, which were caught in Aracaju, state of Sergipe, Brazil. The parasites formed oval plasmodia around the esophagus of L. analis, and elongated plasmodia inside the skeletal muscle of B. marinus, A. luniscutis and L. jocu. Host myoliquefaction was not observed in all the cases studied. The current study provides a morphological and morphometric description of each parasite as well as a comparison with all the species described worldwide. Lack of molecular data impaired specific identification of the parasites. The importance of these parasites is discussed and the need for further studies on infections in Brazilian fish is emphasized because of the high economic impact of some Kudoa species which cause liquefaction in hosts’ muscles and render these fish unsuitable for consumption.
Acesso aberto (Open Access)
Reproductive ecology of the catfish, Hassar affinis (ACTINOPTERYGII: DORADIDAE), in three lakes of the Pindaré- Mearim lake system, Maranhão
(Universidade Federal do Pará, 2017-09) CANTANHÊDE, Lorrane Gabrielle; CARVALHO, Irayana Fernanda da Silva; NUNES, Karla Bittencourt; ALMEIDA, Zafira da Silva de; SANTOS, Nayara Barbosa
Reproductive biology affords fundamental features for the establishment of protective measures for fish. The aim of the present work therefore was to determine the reproductive features of the catfish, Hassar affinis, known locally as bico-deflor, in three lakes of the Pindaré-Mearim Lake System, in the state of Maranhão, with the aim of subsidising the closed season. Monthly collections were carried out between July 2014 and July 2015, when 206 individuals were sampled from Lake Aquiri (LA), 247 from Lake Cajari (LC), and 126 from Lake Viana (LV). In the laboratory, each individual was weighed and measured; a ventral longitudinal incision was then made in order to observe the gonads macroscopically. They were then fixed in Bouin’s solution for microscopic analysis and in Gilson’s solution for an analysis of fecundity. Positive allometry was recorded at the three study sites. The sex ratio for the total period was 3.29F:1M (LA), 2.43F:1M (LC) and 2.15F:1M (LV). Mean length at first sexual maturity was estimated at 10.60 cm (LA), 10.84 cm (LC) and 11.12 cm (LV). The period from March to May was defined as the breeding season for this species in the three lakes. Mean absolute fecundity was 21,634 oocytes (LA), 16,357 oocytes (LC) and 25,898 oocytes (LV). The information obtained through this study indicates that, in addition to being important spawning areas, the three lakes are interconnected in relation to the migratory dynamics of H. affinis, so it is necessary to arrive at a model that would satisfactorily cover the three lakes, considering that the dam has a negative effect on Lake Viana.
Acesso aberto (Open Access)
The role of Lithodoras dorsalis (Siluriformes: Doradidae) as seed disperser in Eastern Amazon
(Sociedade Brasileira de Inctiologia, 2017) BARBOSA, Thiago Augusto Pedroso; MONTAG, Luciano Fogaça de Assis
Ichthyochory is an important process responsible for the high diversity of plant species in tropical flooded forests. Thus, this study aimed to investigate the role of a catfish species, Lithodoras dorsalis, as seed disperser in the flooded forests at the Amazon River mouth, Brazil. Analyzing the stomach contents of 371 individuals of Lithodoras dorsalis, the Germination Potential (GP%) and Germination Speed Index (GSI) of seeds that were removed intact were investigated. This allowed us to evaluate the germination performance of two important species of plants in Amazonia, Euterpe oleracea (Açaí) and Montrichardia linifera (Aninga), after passage through the digestive tract of this catfish species. Given that digestion by L. dorsalis reduced the germination viability of M. linifera and that seeds were often destroyed during consumption, we suggest that L. dorsalis may have a limited role as seed disperser of M. linifera and instead mostly act as seed predator. However, for the species E. oleracea, L. dorsalis was a potential disperser, since the performance of germination of these seeds was improved after digestion. In addition, the number of seeds consumed was directly proportional to the catfish’s body size, reinforcing the role of doradids as potential seed dispersers in tropical forests.
Acesso aberto (Open Access)
Seasonal changes in the gonadossomatic index, allometric condition factor and sex ratio of an auchenipterid catfish from eastern Amazonia
(2011) FREITAS, Tiago Magalhães da Silva; ALMEIDA, Vitor Hudson da Consolação; MONTAG, Luciano Fogaça de Assis; ROCHA, Rossineide Martins da; FONTOURA, Nelson Ferreira
The aim of the present study was to evaluate the seasonal pattern of the gonadosomatic index (GSI), condition factor (K), and sex ratio in the catfish Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) as an approach to identify its reproductive period. A total of 589 A. longimanus specimens (251 males and 338 females) were captured in the rivers of the Caxiuanã National Forest, in the Brazilian state of Pará, between July, 2008 and July, 2009. Among the male specimens, 171 were classified as adults and 80 as juveniles, while there were 249 adults and 89 juvenile females. Using a sinusoidal equation, analysis of the GSI revealed a reproductive asynchrony between the genders, with males attaining their highest GSI values in January, while females peaked in March. For males, the sinusoidal regression for GSI values was significant only when used the complete data set (P=0.001), wears no trend was identified for bimonthly means (P=0.136). For females, by contrast, significant values were obtained for both the complete data set (P=0.012) and bimonthly GSI means (P=0.026). For the condition factor, the sinusoidal equation returned significant seasonal variation in both raw data (P=0.02) and with mean values (P=0.00) for males, but only with raw data for females (P=0.04), which appears to reflect variation in the energy budget between genders. With regard to the sex ratio, more reproductive females were captured than males in January and March, 2009, which suggests a pattern of segregation related to the reproductive process. These parameters are fundamental to the assessment, protection, and management of natural fish stocks, as well as providing guidelines for the development of conservation strategies.
Acesso aberto (Open Access)
X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus
(2015-06) CARDOSO, Adauto Lima; PIECZARKA, Julio Cesar; NAGAMACHI, Cleusa Yoshiko
Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The 1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B. n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.