During the 13th Integrated Academic Week at the Federal University of Rio de Janeiro (UFRJ), master’s student Yan Ribeiro Kurtz de Assumpção, supervised by professors Michael M. Mincarone, Pablo R. Gonçalves, and Gabriel S. Araujo, and in cooperation with the researchers Allan P. B. Pozzobon and Leandro N. Eduardo, was awarded an Honourable Mention for presenting his work entitled: “Unveiling the hidden diversity of Argyropelecus and Sternoptyx (Stomiiformes: Sternoptychidae): Exploring the evolutionary and biogeographic history through mitochondrial DNA”.

The study focuses on hatchetfishes, members of the family Sternoptychidae, a group of deep-pelagic fishes with significant ecological importance due to their role in nutrient cycling, carbon sequestration, and trophic connectivity between oceanic zones. The research revealed that the species diversity within these genera is significantly greater than previously thought, identifying 18 lineages, some of which do not correspond to species described by traditional morphological methods.

The analysis used molecular biology techniques, including the amplification and sequencing of the mitochondrial Cytochrome C Oxidase (COI) gene, combined with phylogenetic and lineage delimitation tools. The findings provide insights into the impact of biogeographic barriers on speciation and underscore the underestimation of deep-sea fish diversity. This study includes specimens collected during the ABRACOS expedition (Acoustics along the BRAzilian COaSt), one of the main projects coordinated by the LMI TAPIOCA.

The study was supported by the UFRJ Graduate Programme in Environmental Science and Conservation (PPG-CiAC/UFRJ), LMI TAPIOCA, CAPES, and the Scripps Institution of Oceanography. It represents a significant advance in understanding the evolutionary and biogeographic history of little-known marine species.