Species delineation of lizardfishes, Saurida pseudotumbil Dutt and Sagar, 1981 and Saurida tumbil (Bloch, 1795) using multivariate tools

Abstract

Morphometric characters of two species of lizardfishes viz.,Saurida pseudotumbil Dutt and Sagar, 1981 and Saurida tumbil (Bloch, 1795), were studied to delineate the species using multivariate techniques. Specimens were collected from Parangipettai and Cochin waters, southern India, for recording data on 21 morphometric characters. Principal component analysis (PCA) was done after log transformation and the first three components explained 93.36% of the total variation. The most important morphometric characters determined using the eigenvectors (coefficients) of these components were post-orbital length, snout to pectoral, snout to pelvic, snout to anal, anal fin base and dorsal fin base, which showed high loading (≥0.8) in the three components. The overlapping ratio between these species ranged from 42.59 to 89.28%. The PCA data cloud of S. pseudotumbil and S. tumbil also reflected the same trend. Therefore, canonical analysis of principal coordinates (CAP) was done which clearly separated the species with maximum case allocation success (100%) for both S. pseudotumbil and S. tumbil, which clearly showed that both the species are different.

Stock differentiation of the greater lizardfish Saurida tumbil (Teleostei: Synodontidae) collected along the western coast of the Arabian Gulf and Sea of Oman using meristic characters

“…Mohanchander et al . (2019) used similar statistical analyses to compare some morphometric characters of S. tumbil and S. pseudotumbil collected from the Cochin coasts in India. In that study, morphometric characters were used to separate S. tumbil from its congener S. pseudotumbil , and such usage revealed its validity.…”

“…Currently, there are no data of greater lizardfish structure among fishing areas of the Arabian Gulf and Sea of Oman using morphometric and meristic characters except for that of Mohanchander et al . (2019) from the Cochin coasts, India. In that study, morphometric characters were used to separate Saurida tumbil from its congener Saurida pseudotumbil , and such usage revealed its validity.…”

First record of the Gracile lizardfish Saurida gracilis (Quoy & Gaimard, 1824) in Mediterranean waters

“…Species belonging to the genus Saurida can be morphologically very similar, leading to possible misidentifications (Mohanchander et al, 2019;Jawad et al, 2021) but recent work has better delineated their taxonomy, with several new species described in the past few decades (e.g., Shindo & Yamada, 1972;Waples, 1981;Inoue & Nakabo, 2006;Russell, 2015;Russell et al, 2015;Yeo & Kim, 2018).…”