# Correction of GenBank’s taxonomic entry error raises a new issue regarding intergeneric relationships among salangid fishes (Osmeriformes: Salangidae)

## TL;DR

This paper corrects a taxonomic error in GenBank for a fish species and reveals new insights into the evolutionary relationships among salangid fishes.

## Contribution

The paper identifies a misidentified mitogenome in GenBank and challenges the synonymization of two fish genera based on genetic data.

## Key findings

- The mitogenome MW291630 was misidentified as N. taihuensis but belongs to N. jordani.
- Protosalanx is not a single clade but contains at least two distinct lineages.
- The genetic divergence between Protosalanx lineages is comparable to divergence between salangid genera.

## Abstract

The GenBank database of publicly available nucleotide sequences is the largest genetic repository providing vitally important resources for downstream applications in biology and medicine. The concern raised about reliability of GenBank data necessitates monitoring of possible taxonomic entry errors. A case of mitochondrial genome (or mitogenome) misidentification for a salangid fish belonging to the genus Neosalanx (Osmeriformes, Salangidae) is considered in this report. The GenBank database contains four complete mitogenome sequences of N. taihuensis with the accession numbers JX524196, KP170510, MH348204, and MW291630. The overall mean p-distance for these sequences is quite high (7.01 ± 0.14 %) but becomes 29-fold lower (0.24 ± 0.05 %) after excluding the MW291630 mitogenome. An analysis of all available nucleotide sequences of salangids has shown that the observed inconsistency in the level of divergence between N. taihuensis mitogenomes is due to species misidentification. It has turned out that the mitogenome MW291630 available in GenBank does not belong to N. taihuensis, but is, in fact, a mitogenome of N. jordani misidentified as N. taihuensis. The resolved taxonomic identity of the MW291630 mitogenome, as well as an extended sample of species with investigated single-marker sequences, has raised some new issues regarding intergeneric relationships in salangid fishes. In particular, the obtained data do not support synonymization of the genus Neosalanx with Protosalanx, as was suggested in the last revision of the salangid classification. As the comparative analysis of interspecific and intergeneric divergences shows, Protosalanx is not an all-inclusive clade that includes all Neosalanx species. Instead, it consists of (at least) two evolutionary distinct lineages with the level of genetic divergence between them matching well the mean value of divergence between the other salangid genera. Further analysis using nuclear genome-wide data is required to have new insights into the evolution of salangid fishes.