Sex identification of Carcinus maenas by analysis of carapace geometrical morphometry

LEDESMA, FEDERICO M.; VAN DER MOLEN, SILVINA; BARÓN, PEDRO J.

JOURNAL OF SEA RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2010 vol. 63 p. 213 - 216

1385-1101

The European green crab Carcinus maenas is a widely spread invasive species. Studying the most recently introduced population of the species in the Atlantic coast off Patagonia, it became apparent to us that carapaces (the dorsal cover of the visceral-cavity detaching from the rest of the exoskeleton after ecdysis) accumulated on the intertidal may be used as a valuable complementary material to analyze the size structure of crabs. However, since growth rate (and consequently size at instar) of crabs differs between males and females, finding a method to distinguish crab sex by observation of carapace morphology was necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. introduced population of the species in the Atlantic coast off Patagonia, it became apparent to us that carapaces (the dorsal cover of the visceral-cavity detaching from the rest of the exoskeleton after ecdysis) accumulated on the intertidal may be used as a valuable complementary material to analyze the size structure of crabs. However, since growth rate (and consequently size at instar) of crabs differs between males and females, finding a method to distinguish crab sex by observation of carapace morphology was necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. necessary to allow the construction of independent size frequency distributions for each sex. In this work, we examined the shape of the carapaces from both sexes of C. maenas, and using Elliptical Fourier Analysis successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. successfully identified sexual dimorphism. Thus, a reliable method to identify sexes by visual observation of the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes. the carapace was developed. Based on our results, we discuss the evolutionary significance of carapace form differentiation of both sexes. differentiation of both sexes.