Phylogenetic prospecting for cryptic species of the genus Merluccius (Actinopterygii: Merlucciidae).

Hakes of the genus Merluccius include 11 valid species as well a number of rare morphotypes suspected to be “cryptic species”. Concatenated nucDNA ITS1-rDNA and mtDNA cyt b sequences plus nested ITS1Nes sequences allowed to ascribe 14 specimens of nine rare morphotypes from the South Pacific and the South Atlantic to the phylogenetic backbone of this genus. Bayesian analyses pointed to M. bilinearis and M. albidus as the oldest species of the genus and the New World cluster, respectively. The phylogenetic status of M. angustimanus from the upper Gulf of California suggests its hybrid origin between M. gayi and M. productus from about 0.25 MYA, although an ever since confinement of a subset of those species cannot be ruled out. The molecular phylodiagnostic test suggests a common origin of all rare morphotypes and the absence of cryptic hake species in the Southern Cone. The molecular background of the morphotypes distributed between the Western Pacific South of New Zealand and the western Atlantic South of Argentina is compatible with their hybrid origin between M. gayi and both, M. australis or M. hubbsi, respectively.This research was partially supported with the project LETSHAKE (AGL2013-4846-R) co-funded by MINECO (Ministerio Español de Economía y Competitividad) and EU-FEDER to M.P. as well as with grant (IN607B 2018/14) to M. P. from Xunta de Galicia-Axencia Galega de Innovación. This work was also partly funded with grants from “Consellería de Educación e Ordenación Universitaria Xunta de Galicia (Galician Regional Government) cofunding from the European Regional Development Fund (ERDF) in the framework of the Operational Program Galicia 2014–2020 (CIM-UVIGO), “A way to build Europe”.Versión del edito