Morphometrical characterization of the Atlantic mudskipper species (Periophthalmus barbarus) (Linnaeus, 1766) (Perciformes; Gobiiae) from Abonema in Port Harcourt, Rivers State, Nigeria

Abstract

Mudskippers are borderline organisms whose biology, systematics and evolution has attracted research attention for so long. There are controversies in their systematics especially because the morphological classifies are plastic and can be dependent on life stage, living conditions and the expertise of the scientist. This paper sort to characterize the Nigerian mudskippers using firstly morphometry, then DNA barcoding and the complete mitogenome sequences. Ten parameters were measured on One hundred specimens and the result was subjected to exploratory data analysis. The Nigerian mudskipper is in size and shape not different from other species found around the world. The standard deviation of all the measurements range from low (0.24-055) for six of the parameters, medium for two (0.56-0.86) and high for the remaining two (0.87-1.17). Low and medium standard deviation is an indication of very low variability in the parameters with the data clustering around the mean closely. Scatter plotting indicated five of the specimen that can be classified as outliers. Principal component analysis indicated two namely PC1 and PC2 as being responsible for 68% of the variance observed. Principal component plots 1 and 2 indicated head width, head depth and snout length loaded positively while only body depth loaded positively for the PC2. The Nigerian species were also amphidromous. The essence of this initial analysis was to see if body measurements will indicate any significant grouping as we plan to select samples for molecular analysis.