Brachyuran crustaceans from the bycatch of prawn fisheries at the mouth of the Amazon river

Abstract

The present paper is a pioneering study on the Brachyura bycatch associated with the artisan prawn fisheries at the mouth of the Amazon River. The study was conducted at four collection sites distributed along the mouth of the Amazon River between the months of January/2009 and January/2010. The animals were caught using handcrafted traps called "matapi", which are used by prawn fisherman in the region. Twenty matapis were used at each collection site. A total of 145 specimens were captured and six species were identified, all belonging to the Trichodactylidae family -Sylviocarcinus maldonadoensis, S. pictus, S. devillei, Valdivia serrata, Dilocarcinus septemdentatus and D. pagei. The most representative species, S. maldonadoensis, S. pictus and S. devillei were classified as regular. Regarding the composition of the capture, there were three specimens of D. pagei , only one male specimen of D. septemdentatus, forty-eight specimens of S. maldonadoensis, sixty-eight specimens of S. pictus, twenty-two specimens of S. devillei and three specimens of V. serrata. In all months, the brachyuran fauna showed a considerably lower biomass when compared to the prawns, representing only 5% of the catch, in a ratio of 1:0.06. For most species, the number of males was always higher than the number of females in almost all collection months. Keywords: Macrobrachium, prawn fishing, Crustaceans, Amazon region, TrichodactylidaeCrustáceos Brachyura da fauna acompanhante da pesca artesanal de camarões de água doce na foz do rio Amazonas resumo O presente trabalho constitui um estudo inédito sobre a fauna de Brachyura associada à pesca artesanal de camarões na foz do rio Amazonas. Este estudo foi realizado em quatro pontos de coleta distribuídos na foz do Rio Amazonas, entre os meses de janeiro/2009 e janeiro/2010. Os animais foram capturados utilizando armadilhas artesanais denominadas "matapis" usados por pescadores de camarão na região. Em cada ponto da coleta foram usados 20 matapis. Foram identificados seis espécies em um total de 145 indivíduos capturados, sendo todos pertencentes a família Trichodactylidae: Sylviocarcinus maldonadoensis, S. pictus, S. devillei, Valdivia serrata, Dilocarcinus septemdentatus e D. pagei. As espécies mais representativas S. maldonadoensis, S. pictus e S. devillei, foram classificadas como regulares. Quanto à composição da captura temos D. pagei com três exemplares, D. septemdentatus com apenas um exemplar macho S. maldonadoensis com 48 exemplares, S. pictus com 68 exemplares, S. devillei com 22 exemplares e V. serrata com 3 exemplares. A fauna de Brachyura apresentou, em todos os meses, uma biomassa consideravelmente menor se comparada a dos camarões, representando apenas 5% da captura, com uma proporção de 1:0,06. Para maioria das espécies a proporção de machos foi sempre superior a de fêmeas em quase todos os meses de coleta.

Natural diet and feeding habits of a freshwater prawn (Macrobrachium carcinus: Crustacea, Decapoda) in the estuary of the Amazon River

“…The areas studied are relatively similar and important to prawn artisanal fishing (Lima et al 2013). Their general landscape show various drainage channels, with varying sizes and depths allowing the daily flooding and formation of a wide diversity of micro-habitats.…”

“…Samples were collected monthly from January 2009 to January 2010 by using a handcrafted trap called "matapis" (30 cm in diameter and 50 cm in length), baited with flour of babaçu fruit (Orbignya speciosa) (Simonian 2006;Lima et al 2013). The flour of babaçu was protected with small cloth bags to avoid ingestion.…”

Reproductive biology of Macrobrachium surinamicum (Decapoda: Palaemonidae) in the Amazon River mouth

“…This activity has great economic importance in the Amazonian rivers; however, few studies on fisheries has been conducted, especially those concerning to bycatch fauna, including freshwater crabs and small fish (Lima et al 2013) and other prawns with low economic value as Macrobrachium surinamicum (Espírito- Santo et al 2005;Bentes et al 2011;Lima and Santos 2014).…”

Extension range of four species of freshwater crabs (Decapoda: Trichodactylidae) in the state of Maranhão, Northeastern Brazil

“…Distribution. Brazil (Magalhães and Turkay, 1996b;Barros and Pimentel, 2001;Magalhães, 2003a;Lima et al, 2013).…”

“…Northeastern South America and Amazon basin in Guyana, French Guyana, Colombia, Brazil, Peru, and Bolivia (Magalhães, 2003a;Magalhães, 2003b;Alves et al, 2010;Silva et al, 2012;Lima et al 2013). Distribution.…”