Light in the darkness: New perspective on lanternfish relationships and classification using genomic and...

Area of Science:

• Marine Biology
• Evolutionary Biology
• Genomics

Background:

• Lanternfishes (Myctophiformes) are ecologically vital, comprising half of mesopelagic vertebrate biomass.
• Previous phylogenetic studies of lanternfishes show conflicting or unresolved relationships at tribal and generic levels.
• Genome-scale data have not been extensively utilized for deep-sea fish phylogenetics.

Purpose of the Study:

• To conduct the first genome-scale phylogenetic analysis of lanternfishes.
• To integrate nuclear genome data with protein-coding genes and morphology for robust evolutionary inference.
• To propose a revised taxonomic classification for Myctophidae based on new phylogenetic hypotheses.

Main Methods:

• Massive parallel sequencing to generate genome-wide DNA datasets.
• Phylogenetic analyses integrating nuclear genomic, protein-coding gene, and morphological data.
• Comparative analysis of resulting phylogenetic hypotheses across different methods and datasets.

Main Results:

• Phylogenetic analyses yielded congruent results across various methods, taxonomic sampling, and data types.
• Neoscopelidae is monophyletic and sister to a monophyletic Myctophidae.
• The study identified incongruence with the current classification, necessitating revisions.

Conclusions:

• A revised classification recognizing five subfamilies within Myctophidae is proposed, elevating three traditional tribes.
• The revised taxonomy reflects monophyletic groups and resolves issues with polyphyletic genera like Myctophum, Lampanyctus, and Nannobrachium.
• The findings provide a robust evolutionary framework for understanding deep-sea fish diversity and ecosystem roles.