Seasonal Breeding Cycles and Sex Ratios of Eight Species of Crabs from Mgazana, a Mangrove Estuary in Transkei, Southern Africa

Emmerson, W.D.

doi:10.2307/1549002

Cited by 97 publications

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“…However, it is possible to find populations of crustaceans with significant deviations from the expected proportion of 1:1, which can be caused by differences in birth rates or mortality rates between the sexes (Johnsson, 2003) and/or the sampling rates (Montague, 1980). Historically, some Uca populations have been recorded with significant deviations from the fisheries proportion (Wolf et al, 1975;Frith & Brunenmeister, 1980;Colby & Fonseca, 1984;Spivak et al, 1991;Emmerson, 1994;Litulo, 2005a;Bedê et al 2008). In the present study, the sex ratio was skewed towards males, in a proportion of 3.5:1 (Table 3).…”

Section: Discussionsupporting

confidence: 51%

Population biology and morphometric sexual maturity of the fiddler crab Uca (Uca) maracoani (Latreille, 1802) (Crustacea: Decapoda: Ocypodidae) in a semiarid tropical estuary of northeastern Brazil

Silva

Ribeiro

2016

lajar

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ABSTRACT. The population biology and size at sexual maturity of Uca (Uca) maracoani were studied for the first time in a semi-arid tropical estuary of northeastern Brazil. A catch-per-unit-effort (CPUE) technique was used to sample the crabs, on the surface and inside burrows, for 60-min sampling periods by one person on a monthly basis during spring low tide periods from June 2013 to June 2014 in an estuary area of Baixa Grande Beach. A total of 406 crabs were obtained, of which 317 were males, 87 non-ovigerous females, and two ovigerous females. Males were larger than non-ovigerous females. The U. (U.) maracoani population presented unimodal size frequency distribution, which may reflect a continuous recruitment, with no disruption of classes and constant mortality rates, indicating a stable population. The overall sex ratio (3.5 males: 1 female) differed significantly from the expected 1:1 proportion. The major cheliped was on the right side in 45.1% of the males, as reported for other fiddler crabs populations. A total of 294 males and 89 females were used in the allometric study. The specimens were measured at carapace width (CW), the major propodus length (MPL) of males, and abdomen width (AW) of females. In males, the relationship between CW and MPL was 22.3 mm CW, which is considered the functional value at maturity. In females, the size at sexual maturity was 19.3 mm CW based on the relationship between CW and AW. The CPUE method is discussed as one of the reasons of the high sex ratio skewed towards males. This is the first account regarding population structure of U. (U.) maracoani in semi-arid tropical areas. Keywords: Uca (Uca) maracoani, population structure, sex ratio, sexual maturity, CPUE technique.Estructura poblacional y madurez sexual del cangrejo Uca (Uca) maracoani (Latreille, 1802) (Crustacea: Decapoda: Ocypodidae) en un manglar semiárido tropical en el noreste de Brasil RESUMEN. La estructura poblacional y la madurez sexual morfométrica del cangrejo Uca (Uca) maracoani fueron estudiadas en un manglar tropical en el noreste de Brasil. Los cangrejos fueron colectados mensualmente durante los periodos de marea baja de junio 2013 a junio 2014. Se utilizó la técnica de captura por unidad de esfuerzo (CPUE) con períodos de una hora de captura realizada por una persona. Se obtuvo un total de 406 cangrejos: 317 machos, 87 hembras no-ovígeras y dos hembras ovígeras. El tamaño de los machos fue significativamente mayor que el de las hembras no-ovígeras. La población mostró una distribución unimodal de frecuencias de tamaños, lo que puede reflejar un reclutamiento continuo, sin interrupción de las clases y las tasas de mortalidad constantes, lo que indica una población estable. La proporción sexual (3.5 machos: 1 hembras) se alejó significativamente de la proporción esperada 1:1. El quelípodo mayor estaba en el lado derecho en el 45,1% de los machos, según lo informado por otras poblaciones.

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Section: Discussionsupporting

confidence: 51%

Population biology and morphometric sexual maturity of the fiddler crab Uca (Uca) maracoani (Latreille, 1802) (Crustacea: Decapoda: Ocypodidae) in a semiarid tropical estuary of northeastern Brazil

Silva

Ribeiro

2016

lajar

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“…Provavelmente a reduzida presença de juvenis durante estas estações pode ser explicada pela ação da temperatura no desenvolvimento e maturação dos tecidos gonadais (ADIYODY & ADIYODY, 1970;WEAR, 1974) e sua ação catalítica sobre as diferentes fases larvais (BOOLOOTIAN et al, 1959). Segundo EMMERSON (1994), uma estratégia reprodutiva comum entre os crustáceos consiste em realizar a postura durante o verão, quando as temperaturas estão elevadas e o fitoplâncton mais abundante, o que facilita o desenvolvimento dos novos indivíduos.…”

Section: Resultsunclassified

Estrutura populacional dos camarões simpátricos Potimirim glabra e Potimirim potimirim (Crustacea, Decapoda, Atyidae) no rio Sahy, Rio de Janeiro, Brasil

Lima

Silveira

Oshiro

2006

Iheringia, Sér. Zool.

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ABSTRACT. Populational structure of the sympatric freshwater shrimps Potimirim glabra and Potimirim potimirim (Crustacea, Decapoda, Atyidae) in the Sahy River, Rio de Janeiro, Brazil. The aim of this work was to get some knowledge about the populational structure of the two sympatric freshwater shrimp species, Potimirim glabra (Kingsley, 1878) and Potimirim potimirim (Müller, 1881) in the Sahy River, Mangaratiba, Rio de Janeiro, Brazil. The specimens were sampled monthly from September 1997 to February 1999 by sieving the marginal vegetation, on rocky surface and among litter on river bottom, with 15-minute effort per sampling period. The animals were sorted sexed and their total and cephalothoracic length were measured. A total of 4,889 individuals were collected in Sahy river: 3,281 P. glabra and 1,608 P. potimirim. The sex ratio for all collected individuals was 1:1 for P. glabra and 1:2.3 for P. potimirim. In both populations, five sexual maturity stages were determined and the populations were constituted mainly of adult freshwater shrimps. This study shows the difference between the recruitment of juveniles along these species. The recruitment for P. glabra occurs throughout the year, except in Spring, while P. potimirim was recorded only in Autumn. The seasonal distribution of ovigerous females of P. glabra is similar to P. potimirim, with reproduction on Spring and Summer.KEYWORDS. Atyidae, freshwater shrimps, populational structure, Potimirim, recruitment.Estação de Biologia Marinha, Universidade Federal Rural do Rio de Janeiro, Rua Sereder s/nº, Itacuruçá, Mangaratiba, 23880-000 Rio de Janeiro, Brasil. (giovalverde@yahoo.com.br; oshiro@ufrrj.br) RESUMO. Este trabalho teve por objetivo obter conhecimento sobre a estrutura populacional de dois camarões de água doce simpátricos, Potimirim glabra (Kingsley, 1878) e Potimirim potimirim (Müller, 1881) no rio Sahy, Mangaratiba, Rio de Janeiro, Brasil. Os indivíduos foram coletados mensalmente durante o período de setembro de 1997 a fevereiro de 1999 utilizando-se peneiras, que foram passadas sob a vegetação marginal, superfície de rochas e pequenas poças d'água, num esforço de 15 minutos por coletor. Os animais foram separados quanto ao sexo e mensurados em relação ao comprimento total e do cefalotórax. Um total de 4.889 indivíduos foram coletados no rio Sahy: 3.281 P. glabra e 1.608 P. potimirim. A razão sexual observada foi de 1:1 para P. glabra e 1:2,3 para P. potimirim. Em ambas populações, cinco estágios de maturidade sexual foram determinados, sendo as populações constituídas principalmente por camarões adultos. O recrutamento de juvenis apresentou diferenças em ambas as espécies. O recrutamento de P. glabra ocorreu durante todo o período de estudo, exceto na primavera, enquanto que P. potimirim foi registrado somente no outono. A distribuição sazonal de fêmeas ovígeras de P. glabra é similar ao de P. potimirim, com reprodução na primavera e no verão. PALAVRAS-CHAVE.Atyidae, camarões de água doce, estrutura populacional, Potimirim, recrutamento.

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“…The major controlling factors appear to be latitude, temperature, larval food availability, and intertidal zonation (Thorson, 1950;Sastry, 1983). The breeding period becomes protected from cool to warm subtropical localities (Emmerson, 1994 (Sastry, 1983). The reproduction in U. thayeri was remarkably seasonal, with a pronounced activity from January to March, and a pause period from April to August, when the ovigerous females were not found.…”

Section: Discussionmentioning

confidence: 99%

Reproductive pattern comparison of Uca thayeri Rathbun, 1900 and U. uruguayensis Nobili, 1901 (Crustacea, Decapoda, Ocypodidae)

Costa

Silva

Negreiros-Fransozo

2006

Braz. arch. biol. technol.

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Seasonal Breeding Cycles and Sex Ratios of Eight Species of Crabs from Mgazana, a Mangrove Estuary in Transkei, Southern Africa

Cited by 97 publications

References 0 publications

Population biology and morphometric sexual maturity of the fiddler crab Uca (Uca) maracoani (Latreille, 1802) (Crustacea: Decapoda: Ocypodidae) in a semiarid tropical estuary of northeastern Brazil

Population biology and morphometric sexual maturity of the fiddler crab Uca (Uca) maracoani (Latreille, 1802) (Crustacea: Decapoda: Ocypodidae) in a semiarid tropical estuary of northeastern Brazil

Estrutura populacional dos camarões simpátricos Potimirim glabra e Potimirim potimirim (Crustacea, Decapoda, Atyidae) no rio Sahy, Rio de Janeiro, Brasil

Reproductive pattern comparison of Uca thayeri Rathbun, 1900 and U. uruguayensis Nobili, 1901 (Crustacea, Decapoda, Ocypodidae)

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