Navegando por Assunto "Caranguejo-uçá"

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Acesso aberto (Open Access)
Cultivo de larvas de Ucides cordatus (LINNAEU, 1763) sob diferentes intensidades luminosas
(2014-10) COTTENS, Kelly Ferreira; SILVA, Ubiratã de Assis Teixeira da; VENTURA, Robson; RAMOS, Fabrício Menezes; OSTRENSKY, Antonio
Ucides cordatus is an edible crab species typical of Brazilian mangroves, and traditionally represents an important economic resource for many coastal populations. The present study investigated the influence of light intensity on the survival and rate of larval development of U. cordatus. Three different levels of luminosity were evaluated: 710 (Light), 210 Lux (Shaded) and 1 Lux (Dark), both in individual and collective cultivation conditions. Significant differences were found for survival of zoea larvae under the different light intensities (P<0.05). The greatest survival rates as well as rates of ecdysis to the megalopa stage were obtained under Light conditions (42% in collective cultures and 30% in individual cultures). In Dark conditions events of metamorphosis to megalopa stage was observed only in 16% of collective cultures and 7% of individual cultures. The result indicates that low light intensities may negatively affect larval survivorship during U. cordatus larval cultivations.
Acesso aberto (Open Access)
Interação de Ucides cordatus Linnaeus, 1763 em manguezais da Ilha de Marajó: uma abordagem ecológica
(Universidade Federal do Pará, 2012) GOMES, Cleidson Paiva; FERNANDES, Marcus Emanuel Barroncas; http://lattes.cnpq.br/8943067124521530
The present study was carried out in the mangroves of Soure, Marajó Island, Pará, Brazil, where the great amount of freshwater intake allows the development of transition zones estuary/river defining the geobotanic limits for mangroves in the state of Pará and, hence, for the leaf-removing mangrove crab (Ucididae). For an ecological approach on the interaction between U. cordatus and mangrove forests the following issues were investigated: i) the relationship between the population characteristics of U. cordatus and different transition levels along the gradient of vegetation between mangrove forests and tidal valley forests, ii) the influence of environmental factors of such transition zones on patterns of size and density of U. cordatus population, iii) the impacts of herbivory of U. cordatus on the seedlings production and the possible effects on recruitment process of these seedlings for mangrove forests. Study sites were classified according to the transition level of the tidal várzea forests, and these values correlated with density and size values of U. cordatus population. In each study site the availability of food by litterfall rates, salinity, and indicators of fishing activities on these areas were determined. The impact of U. cordatus on the recruitment of mangrove stands was evaluated by estimating the rate of herbivory and predation on propagules. The results reveal that in the zone of "high transition" local conditions seem to limit U. cordatus stocks, showing that the density of this species population is much lower compared to those recorded in the "low transition" zone. However, areas of high transition offer more favorable conditions for development of the leaf-removing mangrove crab populations, especially with regard to the variability and availability of food and protection from human action in the region. The indicators of fishing activity on U. cordatus revealed that the mangrove forests of the lower transition zone are more subject to overexploitation, mainly for ease of access. The main via of impact on propagules was the consumption rate of 60%, being the rate of export of propagules by tides of only 1%, thus less relevant. U. cordatus may be considered the most important impact agent on the propagules production of these mangrove forests without showing selectivity by size or maturity of seedlings, being important in the regulation of recruitment rates and, hence, in the population dynamics of Rhizophora’s trees in the mangrove forests on the coastal zone of Marajó Island, in the Brazilian Amazon.
Acesso aberto (Open Access)
Os saberes tradicionais dos pescadores de caranguejo-uçá e o manguezal: o caso de Tamatateua Bragança - Pará, costa Amazônica brasileira
(Universidade Federal do Pará, 2019-12) OLIVEIRA, Francisco Pereira de; SOUZA, Gamaliel Tarsos de; SILVA, Klayton Luiz Campelo; FERNANDES, Marcus Emanuel Barroncas
This study focuses on the empirical knowledge and environmental perceptions of Uçá crab (Ucides cordatus) fishermen from the Tamatateua region, municipality of Bragança, northeast of Pará. The main objective is to describe the fishermen's traditional knowledge on this resource focusing on the ecological knowledge from their perceptions and close relationship with the mangrove ecosystem. used the qualitative research approach, in which the technique and the research instrument were carried out using interviews from a questionnaire designed with semi-structured questions, respectively. Data collection took place between 2017 and 2018, with 14 (fourteen) fishermen of Uçá crab, aged between 22 and 62 years, in which the analytical process made use of content analysis. The results demonstrate that the fishermen have elaborated ecological knowledge about the Uçá crab specimen, as well as the natural and environmental phenomena. They perceive the connection between the human being and the mangrove as a synonym of food, marketing, culture, religiosity, among others, which, in some way, directly influence the knowledge passed on from generation to generation through non-formal and informal education. It was also found that the management of the Uçá crab resource is due to the learning process that occurs daily between kinship (father, son, grandson, uncles and others), as well as in the process and socialization (sharing) between friends of the “ mangrove". On the other hand, it was identified that even using predatory practices and arts, such as the hook, the fishermen recognize them as such, but reveal the idea of maintaining the resource when arguing about the respect in the reproduction periods of the specimen.
Acesso aberto (Open Access)
Selectivity curves of the capture of mangrove crab (Ucides cordatus) on the northern coast of Brazil using bayesian inference
(Instituto Internacional de Ecologia, 2016-06) FURTADO JUNIOR, Ivan; ABRUNHOSA, Fernando Araujo; HOLANDA, Francisco Carlos Alberto Fonteles; TAVARES, Marcia Cristina da Silva
Fishing selectivity of the mangrove crab Ucides cordatus in the north coast of Brazil can be defined as the fisherman's ability to capture and select individuals from a certain size or sex (or a combination of these factors) which suggests an empirical selectivity. Considering this hypothesis, we calculated the selectivity curves for males and females crabs using the logit function of the logistic model in the formulation. The Bayesian inference consisted of obtaining the posterior distribution by applying the Markov chain Monte Carlo (MCMC) method to software R using the OpenBUGS, BRugs, and R2WinBUGS libraries. The estimated results of width average carapace selection for males and females compared with previous studies reporting the average width of the carapace of sexual maturity allow us to confirm the hypothesis that most mature individuals do not suffer from fishing pressure; thus, ensuring their sustainability.