Sexual dimorphism and allometry of external morphology in Oreochromis mossambicus

Sexual dimorphism in growth of conventional morphometric characters was investigated in juveniles and young adults (size range: 31 to 91 mm) of Oreochromis mossambicus. A closely associated set of traits was identified that shows sexually dimorphic growth, which was positively allometric in the male...

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Bibliographic Details
Main Author: Oliveira, Rui Filipe (author)
Other Authors: Almada, Vítor Carvalho (author)
Format: article
Language:eng
Published: 2012
Subjects:
Online Access:http://hdl.handle.net/10400.12/1337
Country:Portugal
Oai:oai:repositorio.ispa.pt:10400.12/1337
Description
Summary:Sexual dimorphism in growth of conventional morphometric characters was investigated in juveniles and young adults (size range: 31 to 91 mm) of Oreochromis mossambicus. A closely associated set of traits was identified that shows sexually dimorphic growth, which was positively allometric in the males. These traits correspond to two different morphological complexes: jaw structure and anal/dorsal fins. The best sex discriminators among this set of traits were premaxilla width, anal fin height and snout length. These findings may be explained in terms of intra- and inter-sexual selection acting together and favouring males with strong and large mouths and high dorsal and anal fins, traits that are important in agonistic displays (jaw and fins), fighting and nest digging (jaw).