Landmark-Based Morphometric and Meristic Variations of the Critically Endangered Catfish, Eutropiichthys vacha from Three Different Populations in Bangladesh

Variation in shape, morphometric & meristic characters of critically endangered catfish Bacha, Eutropiichthys vacha, populations from Kaptai Lake, Meghna River &TanguarHaor (wetland ecosystem) were investigated. A total of twenty six fishes (eight from the Meghnariver, eight from KaptaiLake & ten from Tanguarhaor) samples (as this species is rarely found) were collected from March to November, 2012. Eighteen morphometric & four meristic characters were analyzed along with twenty two truss network measurements. Non parametric Kruskal-Wallis test wasused to compare meristic countsand no significant differences were observed among populations. ANOVA showed significant morphometric differences (p 0.001). For morphometric & landmark measurements, the first discriminant function (DF) accounted for 97.7% & 99.7% & the second DF accounted for 2.3% & 0.3%, respectively, among-group variability and together they explained 100% of the total among group variability. For the morphometric & truss network measurements, plotting discriminant functions revealed high isolation of the populations. The dendrogram based on morphometric &landmarks distances placed Tanguarhaor&Kaptai Lake in one cluster & the Meghna River in another cluster. Due to similar environmental conditions & less geographical differences all the landmark of truss measurements did not contribute to significant body shape difference among the populations. These all analyses will be an effective tool to describe body shape variation of a fish species.