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

Montse Pérez,Pablo Presa,Jesús Matallanas,Domingo Lloris,María Fernández-Míguez

doi:10.1038/s41598-021-85008-9

Abstract

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.

Highlights

Hakes of the genus Merluccius include 11 valid species as well a number of rare morphotypes suspected to be “cryptic species”
We address those issues with the most comprehensive sample collection yet made in this genus, which comprises all 11 valid species[13] as well as M. angustimanus from the Gulf of California[21] and 14 specimens of nine rare morphotypes classified as M. tasmanicus from New Zealand waters[23], M. polylepis from the Pacific coast of Chile[32], M. patagonicus from the Atlantic S outh[23], uncatalogued specimens of M. hubbsi from the Beagle Channel and Puerto Madryn in A rgentina[23], and rare specimens of M. australis from C hile[23] and New Zealand[24]
We examined 1205 specimens from 11 valid hake species and

Summary

Introduction

Hakes of the genus Merluccius include 11 valid species as well a number of rare morphotypes suspected to be “cryptic species”. Resolution of those questions has been complicated by the small number of morphotype samples available, the lack of a systematic sampling plan over a reasonable number of localities and the choice of the most appropriate phylogenetic reconstruction algorithm We address those issues with the most comprehensive sample collection yet made in this genus, which comprises all 11 valid species[13] as well as M. angustimanus from the Gulf of California[21] and 14 specimens of nine rare morphotypes classified as M. tasmanicus from New Zealand waters[23], M. polylepis from the Pacific coast of Chile[32], M. patagonicus from the Atlantic S outh[23], uncatalogued specimens of M. hubbsi from the Beagle Channel and Puerto Madryn in A rgentina[23], and rare specimens of M. australis from C hile[23] and New Zealand[24]. An integrative multimarker phylogenetic reconstruction of genus Merluccius is enforced to determine both, the phylogenetic congruence and synergy between mtDNA (cyt b) and nucDNA (ITS1) sequences for inference of phylogenetic relationships in this genus and the genetic prospecting for cryptic species within the New World supercluster, as suspected on the rare morphotypes described so far

Methods

Results

Conclusion