Addressing the phenotypic plasticity in Boleophthalmus boddarti (Pallas, 1770) from Sundarbans of West Bengal using integrative taxonomy

Mudskippers are considered as borderline organisms whose systematics are debatable because of plasticity in their morphological classification. Hence, their biology, systematics and evolutionary studies have attracted several researchers nowadays. The present work sorts to characterize the Boddart's goggle-eyed goby Boleophthalmus boddarti sampled from Sundarbans of West Bengal from May 2023 to February 2024, employing an integrative taxonomy approach using morphometry and two molecular genes: cytochrome c oxidase subunit (COI) and ribosomal RNA (16S). Fourteen morphometric parameters were measured for 102 specimens and the data were subjected to univariate ANOVA and principal component analysis. The standard deviation ranged from low i.e., 0.11 to 0.40 for eight parameters, medium 0.46 to 0.70 for four parameters and high 1.70 to 1.95 for two parameters. Low and medium standard deviations in parameters indicated the low variability among data clustering more are around the mean closely. Principal component analysis determined those two components, PC1 and PC2, accounted for 78.41 % of the observed variation. Positive correlation seen in plots 1 and 2 between standard length, total length, second dorsal fin length, anal fin length, head length, pre-dorsal length, head depth, first dorsal fin length and body depth. A molecular marker used for the reconstruction of the phylogenetic trees revealed that species followed monophyletic clade in concordance with the specimens of Bangladesh. Interspecific genetic distance ranged from 0.121 to 0.170 while intraspecific distance ranged from 0.002 to 0.016 for COI and for 16S interspecific genetic distances varied from 0.147 to 0.597 while intraspecific ranged from 0.000 to 0.004. The result showed all specimens belong to one species and no speciation seen among populations of three zones of Sundarbans.