Vampire squid taxonomy clarified after 2026 reversal

The 2026 study re‑classified the purported new species Vampyroteuthis pseudoinfernalis as a junior synonym of the original vampire squid V. infernalis, ending a two‑year debate over deep‑sea cephalopod diversity【2】. This correction matters to marine biologists because it restores the view that the ancient order Vampyromorphida is represented by a single extant species, reinforcing the rarity of its lineage.

Taxonomic correction explained

The 2024 claim of a second living vampire squid was based on a specimen from the South China Sea that appeared to differ in tail shape, beak structure, and photophore placement, and its mitochondrial COI and nuclear rDNA sequences seemed distinct【2】. However, the 2026 team, including Smithsonian expert Michael Vecchione, found that these morphological variations fell within the normal range of V. infernalis across life stages, and that soft‑bodied cephalopods often deform during capture. Expanded phylogenetic analysis with additional genetic markers showed no significant divergence, leading to the conclusion that the specimen was not a separate species but the same as the original vampire squid【2】.

Implications for deep‑sea research

The reversal underscores the challenges of sampling deep‑sea organisms, where limited specimens and pressure‑induced damage can mislead taxonomic assessments. It also highlights the limitations of relying on single‑gene sequencing for species delineation, prompting calls for more comprehensive genomic approaches in future studies【2】. With V. infernalis reaffirmed as the sole living member of Vampyromorphida, the order remains a living fossil dating back over 300 million years, emphasizing its evolutionary significance.

What to watch

• Upcoming deep‑sea expeditions targeting abyssal zones may uncover additional specimens that could test the current single‑species status.
• Advances in multi‑gene or whole‑genome sequencing techniques could provide clearer resolution for cephalopod taxonomy.
• Any new peer‑reviewed publications that revisit the phylogeny of Vampyromorphida, especially those incorporating broader geographic samples.

The 2026 correction restores confidence in the taxonomy of one of the ocean’s most enigmatic creatures, but it also serves as a reminder that deep‑sea biodiversity assessments remain provisional until more robust data are gathered.