Morphological and meristic characters of six rabbitfish species (Family: Siganidae) in Kenya

Abstract

Siganus species (rabbitfishes) are caught by artisanal fishers in Kenyan marine waters. The identification of recently captured rabbitfish species is based on colour patterns, but colours fade after death or during preservation, making species identification more difficult. Morphometric measurements and meristics are then useful in differentiating between species. Twenty-four morphological and twelve meristic characteristics of rabbitfish were obtained from samples collected at six landing sites along the Kenyan coast. Principal Component Analysis (PCA) and Mann-Whitney U-tests were used to evaluate variability among the species. Four of six rabbitfish species showed similar body morphometry and could not be distinguished using PCA analysis, but Siganus stellatus and S. luridus differed from the other species and each other. No clear morphological evidence of separate stocks of individual rabbitfish species was found, apart from S. rivulatus for which the sample size was small. It is recommended that existing taxonomic descriptions are updated to include additional distinctive characters documented in this study.