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Vol. 49 No. 2, 2010
Reproductive Biology
of the Freshwater Shrimp Atya scabra (Leach, 1815) (Crustacea: Atyidae)
in Ilhéus, Bahia, Brazil
Alexandre
Oliveira Almeida1,*, Emerson Contreira Mossolin2, and Joaldo Rocha Luz1
1Departamento
de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rod.
Ilhéus-Itabuna, km 16, CEP 45662-900, Ilhéus, Bahia, Brazil
2Laboratory of Bioecology and Crustacean Systematics
(LBSC), Department of Biology, Faculty of Philosophy, Sciences and
Languages of Ribeirão Preto (FFCLRP), University of São Paulo (USP),
Av. Bandeirantes, 3900, CEP 14040-901, Ribeirão Preto, São Paulo,
Brazil. E-mail:ecmossolin@yahoo.com.br
Alexandre
Oliveira Almeida, Emerson Contreira Mossolin, and Joaldo Rocha Luz
(2010) Reproduction and population aspects of the freshwater
shrimp Atya scabra in the Santana River, city of Ilhéus, state of
Bahia, Brazil, were studied from Apr. 2004 to May 2005. During
these 14 mo, 3752 individuals were captured, with a sex ratio of 1.01
males for each female. The total number of individuals caught per
month ranged 80-532. Males were generally larger than
females. The smallest female found (5.40 mm in carapace length
and 29.03 mm in total length) was ovigerous, which indicates that only
adult individuals were caught. Ovigerous females were found every
month, which indicates continuous reproduction and a high index of
reproductive activity during the year. The highest reproduction
indices were observed in May (94.3%) and Oct. (98.6%) 2004, and Mar.
(93.7%) 2005. Fecundity ranged 870-8907 eggs, with a mean of 3811
(±1992.87) eggs per female. The size of the females and their
fecundity were positively correlated. The distribution of
individuals in length classes by month showed that representatives of
smaller classes occurred throughout almost the entire study
period. This indicates a constant input of individuals into the
population, which corroborates the characterization of the reproductive
period as being continuous, and explains the large numbers of ovigerous
females found each month. The 2nd abdominal segment is
proportionally larger in females than in males, in width, height, and
pleural length: these female secondary characteristics are related to
an increased incubation area for eggs.
Key words: Caridea, Camacuto Shrimp,
Reproduction, Secondary sexual characters, Freshwater.
*Correspondence: E-mail:aalmeida@uesc.br
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