Data from: Barcoding snakeheads (Teleostei, Channidae) revisited: discovering greater species diversity and resolving perpetuated taxonomic confusions

Snakehead fishes of the family Channidae are predatory freshwater teleosts
from Africa and Asia comprising 38 valid species. Snakeheads are important
food fishes (aquaculture, live food trade) and have been introduced widely
with several species becoming highly invasive. A channid barcode library
was recently assembled by Serrao and co-workers to better detect and
identify potential and established invasive snakehead species outside
their native range. Comparing our own recent phylogenetic results of this
taxonomically confusing group with those previously reported revealed
several inconsistencies that prompted us to expand and improve on previous
studies. By generating 343 novel snakehead coxI sequences and combining
them with an additional 434 coxI sequences from GenBank we highlight
several problems with previous efforts towards the assembly of a snakehead
reference barcode library. We found that 16.3% of the channid coxI
sequences deposited in GenBank are based on misidentifications. With the
inclusion of our own data we were, however, able to solve these cases of
perpetuated taxonomic confusion. Different species delimitation approaches
we employed (BIN, GMYC, and PTP) were congruent in suggesting a
potentially much higher species diversity within snakeheads than currently
recognized. In total, 90 BINs were recovered and within a total of 15
currently recognized species multiple BINs were identified. This higher
species diversity is mostly due to either the incorporation of
undescribed, narrow range, endemics from the Eastern Himalaya biodiversity
hotspot or the incorporation of several widespread species characterized
by deep genetic splits between geographically well-defined lineages. In
the latter case, over-lumping in the past has deflated the actual species
numbers. Further integrative approaches are clearly needed for providing a
better taxonomic understanding of snakehead diversity, new species
descriptions and taxonomic revisions of the group.