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

• Published in: Latin american journal of aquatic research Vol. 44; no. 4; pp. 671 - 682
• Main Authors: de Oliveira Silva, Francisca Mariana Rufino, Bezerra Ribeiro, Felipe, Arruda Bezerra, Luis Ernesto
• Format: Journal Article
• Language: English
• Published: Pontificia Universidad Catolica de Valparaiso, Escuela de Ciencias del Mar 01-09-2016; Pontificia Universidad Católica de Valparaíso. Facultad de Recursos Naturales. Escuela de Ciencias del Mar
• Subjects: FISHERIES; MARINE & FRESHWATER BIOLOGY; OCEANOGRAPHY; Estados Unidos; proporción sexual; population structure; sexual maturity; madurez sexual; CPUE technique; Uca (Uca) maracoani; biología poblacional; sex ratio; técnica de CPUE
• ISSN: 0718-560X; 0718-560X
• DOI: 10.3856/vol44-issue4-fulltext-2

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.