Allometry and sexual dimorphism of the Neotropical freshwater anomuran Aegla marginata Bond-Buckup & Buckup, 1994 (Crustacea, Anomura, Aeglidae)

Abstract

Th is study analyzes ontogenetic allometry in Aegla marginata Bond-Buckup & Buckup, 1994, a freshwater crustacean, in order to evaluate the growth patt ern and the presence of sexual dimorphism, using a multivariate approach. Th e specimens were sampled from streams in Intervales State Park, São Paulo State, Brazil. For each specimen, we measured the following structures: carapace length and width, chelae height and length, and abdomen length. Allometry was evaluated using Jolicoeur's multivariate allometric coeffi cient. Our results showed that for females, ABL (abdomen length) and LCH (left chelae heigh) presented positive allometry; LCL (left chelae length) and RCH (right chelae heigh) isometry; and CL (carapace length), CW (carapace width), and RCL (right chelae length) negative allometry. For males, RCH, LCH, and LCL presented positive allometry; RCL (right chelae length) isometry; and CL, CW, and ABL negative allometry. In addition, sexual dimorphism was amplifi ed with body size. keY wordsMultivariate allometric coeffi cient, relative growth, energy investment, sexual selection. Silva et al. 2Allometry and sexual dimorphism of Aegla marginata Nauplius, 25: 2017016

Sexual Allometric Monomorphism in Araucan Pig from Colombia: Preliminary Results

“…In order to test whether dimorphism increases with body size, a canonical discriminant analysis was performed to obtain the scores of individuals of the two sexes in a discriminant axis. Afterwards, following similar works [ 20 ], an ANCOVA based on these scores was used to test the differences between sexes and the interaction with the generalized body size (first PCA axis). Statistical analysis was done with PAST v. 2.17c software [ 21 ].…”