Morfometria comparada das espécies da família Ocypodidae (Crustacea, Brachyura) na Ilha de Itamaracá - Pernambuco

• Autor(a) principal: SILVA, Lucas Nunes da
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/7942
• topic: Morfometria; Ocypodidae; Caranguejo violinista; Alometria; CIENCIAS AGRARIAS::RECURSOS PESQUEIROS E ENGENHARIA DE PESCA

Through the techniques morphometry geometric and linear the objective of this study was to evaluate the variation of the shape in three regions of the body: tergites (dorsal view of the carapace), sternites and abdomen (ventral view) and chelipod in different species of fiddler crab captured on the coast of Pernambuco; verifying if existent deformations are linked to the environmental chararteristics (sedimentary profile, organic matter, distance of the water line) in which the respective species are inserted; Leptuca leptodactyla (Rathbun, 1898) Leptuca thayeri (Rathbun, 1900); Minuca mordax (Smith, 1870), were captured in the period from December 2016 to March 2017. 428 crabs were captured, of which, 80 L. leptodactyla (35 females and 45 males), 232 L. Thayeri (95 females and 137 males) and 116 M. mordax (42 females and 74 males). For the description of the substrate type, the descriptive statistics regarding the mean and standard deviation of the mean were used to evaluate possible statistical differences between the granulometric profile and the organic matter content between the collection points. For the allometric and morphological analysis the crabs were measured with the aid of a pachymeter, with an accuracy of 0.05 mm: 1 - Carapace length (CC); 2 - Carapace width (LC); 3 - Body height (AC); 4 - Frontal Width (OD); 5 - Width of maxilliped (LM); 6 - Length of maxilliped (CM); 7 - Width of the 4th abdominal somite (L4); 8 - Width of the 5th abdominal somite (L5); 9 - Length of abdomen (CA); 10 - Height of the chellipod (AQ); 11-Length of the chellipod (CPq). For males, the most developed chelipod was measured; for females only the right chelopod was measured. Subsequently the crabs were individually photographed in their dorsal, ventral and outer portion of the largest chelipod for males and the right chelipod for females, with the aid of a digital camera parallel to the horizontal plane attached to a tripod, with a 50 mm focal length lens. To determine the shape of the abdomen, 8 anatomical landmarks were selected in the ventral view; 10 anatomical landmarks for determination of carapace shape in dorsal view and 6 landmarks for chelipod region. To the specie L. thayeri the carapace width varied of 0.,50 to 2.78 cm; 0.40 a 2.49 cm to M. mordax e 0.51 a 1.07 cm to L. leptodactyla. Through the PCA it was possible to observe the separation of the three species, for both males and females. Through the principal component analysis (PCA), it was possible to observe the separation of the three species, for both males and females. The separation of females was more noticeable, with a higher overlap of males of M. mordax and L. thayeri. In the PERMANOVA (one-way) analysis, the groups of females presented significant differences (P<0.0001), in the male individuals, the M. mordax and L. thayeri species did not present significant differences in the groups separation (P<0.2552). In the dorsal view, both species and sexes were considered different, based on the distance of Procrustes (P<0.0001), in the ventral view in females, only L. leptodactyla and M. mordax were considered equal (P= 0.2491), for males all the groups showed different with L. thayeri and L. leptodactyla presenting the highest distance (P<0.0001). For the female and male, the cheliped region were considered different with L. thayeri and M. mordax presenting lower distance (P<0.0001) for both sexes. The results suggest that the morphological traits and allometric behavior of the species are important indicators of habitat use and niche specialization, a useful framework to understand the organization of ocipodides. In particular, this framework would be useful for understanding the consequences of changes in environmental conditions (eg, climate change, habitat fragmentation) on the functional diversity of violinist crabs.