Can contrasting environmental conditions of mangroves induce morphological variability in Aratus pisonii (Crustacea: Brachyura: Sesarmidae)?

• Published in: Scientia marina Vol. 80; no. 3; pp. 349 - 358
• Main Authors: López-Sánchez, Beatriz, Quintero-Torres, Enrique, Oliveiras-Durand, Adriana
• Format: Journal Article
• Language: English
• Published: Barcelona Consejo Superior de Investigaciones Científicas 2016
• Subjects: Adaptation; Animal reproduction; Aquatic crustaceans; Aratus; Aratus pisonii; Biomechanics; Brachyura; chelipeds; classic morphometry; Coastal environments; Comparative analysis; Comparative studies; Crustaceans; Decapoda; Energy budget; Environmental conditions; Environmental factors; Females; Genetic variability; Habitats; Life history; mangrove crab; Mangrove swamps; Mangroves; Marine crustaceans; Mechanical properties; Morphology; Morphometry; multivariate methods; Populations; R&D; Rainy season; Research & development; Resource availability; Salinity; Sesarmidae; Sexual dimorphism; Studies; Variability; Wet season; Venezuela; multivariate methods; dimorfismo sexual; mangrove crab; morfometría clásica; métodos multivariados; classic morphometry; sexual dimorphism; quelípedos; chelipeds; cangrejo de manglar
• ISSN: 0214-8358; 1886-8134
• DOI: 10.3989/scimar.04427.27A

Aratus pisonii is one of the most common crab species in Neotropical mangroves. It shows great plasticity in its life history traits, which makes it an interesting subject for comparative studies. This study evaluated the morphometric variability in five populations of A. pisonii inhabiting mangroves with different degrees of structural development under contrasting environmental conditions. Mangrove forests located on the northwest coast of Venezuela were studied during the rainy season in 2006. The results showed morphometric differences and interaction between sampling sites and sex (PERMANOVA, P=0.0001), as well as the presence of five morphological groups in males and four in females. The findings support the existence of sexual dimorphism. Females from the dwarf hypersaline mangrove showed a wide variability associated with the chelipeds. The differences in crab morphology between sites seem to be related to a combination of environmental factors that is unique for each habitat, leading to the formation of different morphological groups, in which the mangrove structural development (resource availability) and salinity (which compromises the energy budget) play an important role. The presence of more robust chelipeds in females from the dwarf hypersaline mangrove seems to reflect an adaptation to the biomechanical properties of the leaves (sclerophylly).