Morphometric differentiation between two sympatric Macrobrachium Bates, 1868 shrimps (Crustacea: Decapoda: Palaemonidae) in West‐African rivers

Abstract

A comparative morphometric study was performed on two species of shrimps, Macrobrachium macrobrachion (Herklots, 1851) and Macrobrachium vollenhovenii (Herklots, 1857). In total, 714 specimens (563 males and 151 females) originating from four rivers in Ivory Coast were analysed. The morphometry was carried out on 33 measurements; seven meristic and four morphological characters and ratios were calculated from the measurements. Data were analysed using univariate, bivariate and multivariate statistics. Meristic and morphological characters did not allow separation of distinct species. However, metric variables and ratios clearly discriminated the two species. The characters (merus/palm, carpus/palm, palm width/palm length, carpus width/carpus length, palm width) related to the form and the size of second pereiopods could be used for the discrimination of both species. This study, by allowing accurate identification of these species, will facilitate future research.

Keywords:

• Morphometric differentiation
• Macrobrachium vollenhovenii
• Macrobrachium macrobrachion
• rivers
• West Africa

Acknowledgements

The authors would like to express their gratitude to the staff of the Laboratoire d'Environnement et de Biologie Aquatique, Université Abobo‐Adjamé (Ivory Coast). We sincerely thank Dr Da Costa Kouassi Sebastino (CNRA, Ivory Coast) for the samples provided and Mr Y. A. O. Kouamé for shrimp drawing. The improvement of the general writing, particularly of the English, of the manuscript by Dr Seka M. Arsène (Université d'Abobo‐Adjamé, Ivory Coast) is greatly appreciated.