Molecular phylogenetic reconstruction and taxonomic investigation of eelpouts (Cottoidei: Zoarcales) based on Co-1 and Cyt-b mitochondrial genes

Abstract

The infraorder Zoarcales (Cottoidei), or eelpouts, includes about 400 species of coldwater fishes concentrated mainly in the North Pacific. To date, the molecular phylogenetic methods in combination with morphological data have significantly contributed to understanding the taxonomic composition of this group and made it possible to confirm/refute validity of some families of obscure origin. In spite of the growing amount of new data on taxonomy and evolution of eelpouts, a consideration of the original and independent data is obviously needed to verify the existing knowledge of this taxon. In this study, which is based on concatenated matrix of Co-1 and Cyt-b mitochondrial genes, as well as relying on the samples from seven families and 45 species of eelpouts, we have reconstructed the phylogeny, which is generally consistent with previous inferences. Despite the resolution of the original data matrix is low, we have demonstrated the monophyletic origin of the families Zoarcidae and Anarhichadidae, as well as Neozoarcidae, previously related to Stichaeidae and recently revised Eulophiidae. The polyphyletic patterns amongst some subfamilies in Stichaeidae have been confirmed, whereas Opisthocentrinae and Pholidae seem to constitute a valid family-level taxon. Our results provide new opportunities with respect to taxonomic relationships in the complex and diverse group of eelpouts , whose part in the tree of life is not covered by recently flourishing multilocus phylogeny of teleost fishes. In light of the data obtained, the necessity of more unified and reproducible approaches to resolve the issues of evolution and taxonomy of such a complex group as Zoarcales becomes more evident.

From scales to armor: Scale losses and trunk bony plate gains in ray-finned fishes

“…2014), Lycodes (Turanov et al. 2017), Cryptacanthodes (Radchenko et al. 2011), Ocosia (Smith et al.…”

From scales to armour: scale losses and trunk bony plate gains in ray-finned fishes

“…Indeed, when looking at lineage-specific phylogenies for the groups in which suspicious scale re-acquisition was inferred, we can observe that the relationships are often different from the ones found in the large phylogeny proposed by Rabosky et al (2018). As a matter of fact, specific phylogenies of Clariger and Luciogobius genera (Yamada et al, 2009), Parupeneus (Song et al 2014), Lycodes (Turanov et al 2017), Cryptacanthodes (Radchenko et al 2011), Ocosia (Smith et al 2018), Notothenia (Near et al, 2018), Lophiocharon (Arnold and Pietsch, 2012), Perulibatrachus (Rice and Bass 2009) and Stomias (Kenaley et al 2014) genera all present differences with the topology of Rabosky et al (2018) we used in our reconstruction (the problematic subtrees are presented Fig. S11).…”

Antifreeze protein dispersion in eelpouts and related fishes reveals migration and climate alteration within the last 20 Ma

“…A number of phylogenetic and taxonomic studies have elucidated the relationships amongst the infraorder Zoarcales and this information is summarized in Fig 1 [19,[43][44][45][46]. To confirm and bolster the connections within the tree of Zoarcales, (particularly for the polyphyletic Stichaeidae, the radiated shanny, and Antarctic eel pouts), cytochrome oxidase (COX) gene sequences from these (or closely related) species were downloaded and an alignment was generated (S1 Fig).…”

“…Species names are coloured in a rainbow pattern from red to purple from earliest to latest time of divergence of each family. The location of the Cryptacanthodidae varies between studies (denoted with a dotted line) [19,46] and some Stichaeidae cluster with Pholidae [44][45][46]. Information on Lycodinae and radiated shanny was limited.…”