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

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.

Berlam Balığının Türkiye'nin Doğu Karadeniz Kıyılarında Dağılımının Genişlemesi

“…Generated COI and 16S rRNA sequences were deposited in GenBank (Accession numbers: COI, MZ540345-MZ540346; 16S rRNA, MZ540342-MZ540344). The maximum likelihood tree generated with COI and 16S rRNA revealed a clear separation of M. merluccius from other Merluccius species, in harmony with previous reports (Campo et al, 2007;Perez et al, 2021;Quinteiro et al, 2000). The Black Sea specimens nested with reference M. merluccius sequences, yet there was no clear separation based on geographic origin (Figure 2).…”

“…The genus Merluccius comprises 12 species widely distributed along the coasts of Europe, America, and Africa. Phylogenetic analysis based on mitochondrial and nuclear sequences indicates the presence of two distinct clades: American clade and Euro-African clade (Campo et al, 2007;Perez et al, 2021;Quinteiro et al, 2000). The Euro-African clade includes the European hake.…”

Population genomics of coastal Pacific Hake

“…It is plausible that these winter samples included Pacific Hake that typically resided farther south in the range but had migrated farther north due to warmwater conditions, although this is speculative. To better assess this possibility, genomic analyses of Pacific Hake off the coast of Mexico and further south are warranted, as previous genetic work found equivocal levels of differentiation in these regions (Silva-Segundo et al 2011;Iwamoto et al 2015;García-De Leon et al 2018;Pérez et al 2021). Additionally, our outlier analyses detected 29 loci putatively under selection when including SS samples and suggested that adaptive differences have evolved in the inland resident populations.…”

“…2018; Pérez et al. 2021). Previous genetic work in Pacific Hake identified three genetically distinct populations: a coastal population from Queen Charlotte Sound to Costa Rica (from 55°N to 10°N); a resident population in the inland waters of the Salish Sea (SS), which is characterized by weak differentiation among regions (i.e., Puget Sound and the Strait of Georgia [SOG]); and a third population isolated in the northern Gulf of California (Iwamoto et al.…”

“…For instance, Pacific Hake were traditionally thought to be distributed along the majority of the west coast of North America (generally from 55°N to 25°N; Ressler et al 2007;Edwards et al 2022); however, the distribution may extend down to Columbia (2°N) if the suggested synonymy of Panama Hake M. angustimanus with M. productus remains valid (Silva-Segundo et al 2011;Eschmeyer and Fong 2022). Much of this uncertainty may be attributed to overlapping morphometrics and meristics and low levels of intraspecific genetic differentiation (Quinteiro et al 2000;Silva-Segundo et al 2011;García-De Leon et al 2018;Pérez et al 2021). Previous genetic work in Pacific Hake identified three genetically distinct populations: a coastal population from Queen Charlotte Sound to Costa Rica (from 55°N to 10°N); a resident population in the inland waters of the Salish Sea (SS), which is characterized by weak differentiation among regions (i.e., Puget Sound and the Strait of Georgia [SOG]); and a third population isolated in the northern Gulf of California (Iwamoto et al 2004(Iwamoto et al , 2015García-De Leon et al 2018).…”