Integrative taxonomy-based discovery of Dussumieria modakandai sp. nov. from India

This study is based on integrative taxonomy and reports a new fish species Dussumieria modakandai sp. nov. from India. The new species differs from three valid species within the genus by a combination of characters such as longer maxilla (9.1%-9.9% standard length vs. 8.7% in Dussumieria elopsoides, 6.3%-8.5% in Dussumieria acuta) and one or two rows of small conical teeth on palatine (vs. several rows in D. elopsoides and Dussumieria albulina). It also differs by the absence of longitudinal striae on the posterior side of body scales (vs. presence in D. acuta and D. albulina) and the absence of parasphenoid teeth (vs. presence in D. acuta). The maxilla length of D. modakandai sp. nov. is greater than snout length, which distinguishes it from other congeners. The multivariate analysis of morphometric characters using PCA differentiated the new species from D. elopsoides and D. acuta samples collected in this study. The molecular analysis, based on cytochrome c oxidase I, distinguished the new species from D. acuta, D. albulina and D. elopsoides with a high genetic distance of 13.73%, 12.22% and 12.74%, respectively. The maximum-likelihood phylogenetic tree and automatic barcode gap discovery analysis showed the existence of six putative species in Dussumieria. Even the exhaustive sub-clade formation within species and high intra-species genetic distance in D. acuta (1.59) and D. modakandai (1.95) indicate the possibility of a few more cryptic species. This warrants comprehensive sample collection across the distribution range and integrative taxonomic study of the genus Dussumieria.