Vampire Squid taxonomy correction confirms single surviving species

The 2026 re‑examination confirmed that Vampyroteuthis pseudoinfernalis is not a distinct species but the same as the known V. infernalis, keeping the vampire squid as the only extant member of the order Vampyromorphida【2】.

Confirmation of a single species

Researchers who first announced a second living species of vampire squid in 2024 based their claim on morphological differences and genetic sequences【2】. A follow‑up study published in 2026 re‑analysed the same evidence and found no consistent differences, concluding that the purported V. pseudoinfernalis is a junior synonym of V. infernalis【2】. This correction restores the long‑standing view that the vampire squid is the only surviving member of the ancient cephalopod order Vampyromorphida, a status originally established after its discovery in the 1898–1899 Valdivia Expedition【1】.

Implications for deep‑sea taxonomy

The reversal highlights the self‑correcting nature of scientific taxonomy, where new data can overturn recent classifications. It also underscores the difficulty of distinguishing deep‑sea species, given limited specimens and the “Lazarus effect” that can obscure true biodiversity in the ocean’s abyssal zones【1】. The vampire squid’s unique traits—bioluminescent photophores, low‑oxygen metabolism, and a webbed “cloak”—remain key identifiers for the order, reinforcing its role as a phylogenetic relict【1】.

What to watch

• Future taxonomic revisions – Additional deep‑sea sampling could reveal further cryptic species or confirm the singular status of V. infernalis.
• Genetic studies – Advances in sequencing may provide clearer differentiation criteria for deep‑sea cephalopods.
• Habitat monitoring – Changes in oxygen minimum zones could affect the vampire squid’s distribution and survival.