Reproductive aspects of Macrobrachium amazonicum (Decapoda: Palaemonidae) in the State of Amapá, Amazon River mouth

Abstract

Macrobrachium amazonicum is an indigenous prawn vastly distributed in basins of South America, widely exploited by artisanal fisheries in northern and northeastern Brazil and, with great potential for aquaculture. This study aimed to investigate general aspects of population structure and reproductive characteristics (size at first maturity, fecundity and reproductive output) of M. amazonicum from two important areas to artisanal prawn fishing located at the mouth of the Amazon River, State of Amapá. The specimens were captured using 20 handcrafted traps called "matapi". A number of 5,179 prawns were captured, 2,975 females and 2,195 males resulting in 1.35:1 female to male ratio. Santana Island and Mazagão Velho showed females predominated in the population. A reproductive peak period was observed from January to April/2009 and in December/2010, coinciding with the period of higher rainfall. The recruitment peak occurred in June and July/2009. Egg-bearing females ranged in size (carapace length) from 11.10 to 29.6 mm. Fecundity increased with female size and reached up to 7,417 eggs. This amount of eggs is considered low if compared with other Macrobrachium estuarine species. Mean egg volume increased gradually from 0.121 to 0.24 mm³ during embryogenesis, representing 68.5% of overall increase from Stage I to Stage III. Eggs of M. amazonicum are small; this is typical for Macrobrachium species, which depends on brackish water to complete the larval development. Irrespective of female size, reproductive output of M. amazonicum varied between 4.8 and 21.85% of their body weight into eggs production. KEYWORDS: Palaemonid eggs, first maturation, fecundity, morphometric relationships, reproduction Aspectos reprodutivos do camarão Macrobrachium amazonicum (Decapoda: Palaemonidae) no estado do Amapá, foz do rio Amazonas RESUMO Macrobrachium amazonicum é uma espécie nativa vastamente distribuída nas bacias da America do Sul, sendo largamente explorada por pescadores artesanais no Norte e Nordeste do Brasil e com grande potencial para aquicultura. O objetivo deste trabalho foi abordar aspectos gerais da estrutura populacional e biologia reprodutiva (tamanho de primeira maturação, fecundidade e investimento reprodutivo) de M. amazonicum de duas importantes áreas de pesca artesanal de camarão localizada na foz do rio Amazonas, no Estado do Amapá. Os exemplares foram capturados usando 20 armadilhas artesanais, conhecidas localmente como matapi. Um total de 5.179 camarões foi capturado, dos quais 2.975 eram fêmeas e 2.195 eram machos, dando uma razão sexual geral de 1,35: 1 em favor das fêmeas. As proporções sexuais nas áreas de Ilha de Santana e Mazagão mostraram fêmeas predominando na população. Os picos reprodutivos nas duas áreas ocorreram de Janeiro a Abril/2009 e em Dezembro/2010, coincidindo com o período mais chuvoso. Os picos de recrutamento foram observados em junho e julho de 2009. O tamanho das fêmeas ovígeras variou de 11,10 mm a 29,6 mm de comprimento de carapaça. A fecundidade aumentou com o tamanho d...

Male morphotypes of the freshwater prawn Macrobrachium brasiliense (Decapoda: Caridea: Palaemonidae)

“…The occurrence of morphotype differences in populations of Macrobrachium from inland streams, as reported here, is uncommon. These environments have lower food availability than estuaries and larger rivers (Chanton & Lewis, ; González‐Gordillo & Rodrigues, ), where multiple morphotypes have commonly been recorded in M. amazonicum (Freire et al, ; Lima et al, ; Silva et al, ). In general, prawn species from inland streams, such as M. brasiliense , have an abbreviated larval development (Anger, ; Jalihal, Sankolli, & Shenoy, ), which is an adaptation to low nutrient availability.…”

“…Taking M. amazonicum as an example, several studies were made after the description of morphotypes (Moraes- Riodades & Valenti, 2004), and reported the presence or absence of multiple morphotypes, depending on the population. Among the studies that found multiple morphotypes in M. amazonicum, many addressed estuarine populations (Flexa, Silva, & Cintra, 2005;Freire, Bentes, Fontes, & Silva, 2017;Freire, Marques, & Silva, 2012;Lima et al, 2014;Lucena-Fredou, Rosa Filho, Silva, & Azevedo, 2010;Santos, Sampaio, & Soares-Filho, 2006;Silva et al, 2019) and fewer addressed populations from inland rivers (Pantaleão et al, 2014;Vergamini, Pileggi, & Mantelatto, 2011).…”

“…These environments have lower food availability than estuaries and larger rivers (Chanton & Lewis, 2002;González-Gordillo & Rodrigues, 2003), where multiple morphotypes have commonly been recorded in M. amazonicum (Freire et al, 2017;Lima et al, 2014;Silva et al, 2019). In general, prawn species from inland streams, such as M.…”

Conhecimento e Manejo Sustentável da Biodiversidade Amapaense

“…No estuário amazônico, há uma leve predominância de fêmeas na população, principalmente no período reprodutivo (LIMA, 2014). Para fêmeas de M. amazonicum cultivadas na Colômbia, Aya-Baquero e Velasco-Santamaría (2013) descreveram comprimento total variando de 4,0 a 5,8 centímetros.…”

“…Para fêmeas de M. amazonicum cultivadas na Colômbia, Aya-Baquero e Velasco-Santamaría (2013) descreveram comprimento total variando de 4,0 a 5,8 centímetros. Porém, na natureza há registro de indivíduos capturados medindo com 15 centímetros de comprimento total (LIMA, 2014). No nordeste do Brasil, há registro de capturas de animais com comprimento entre 4,5 e 10,5 centímetros (SAMPAIO et al, 2007).…”