The first global deep-sea stable isotope assessment reveals the unique trophic ecology of Vampire Squid Vampyroteuthis infernalis (Cephalopoda)

Alexey V Golikov,Elizabeth K Shea,Rigoberto Rosas-Luis,Jónbjörn Pálsson,Amanda L Reid,José C Xavier,Jonathan D Ablett,Gudmundur Gudmundsson,Rushan M Sabirov,Ian G Gleadall,Hendrik J Hoving,Richard Schwarz,Filipe R Ceia,Heather Judkins

doi:10.1038/s41598-019-55719-1

Abstract

Vampyroteuthis infernalis Chun, 1903, is a widely distributed deepwater cephalopod with unique morphology and phylogenetic position. We assessed its habitat and trophic ecology on a global scale via stable isotope analyses of a unique collection of beaks from 104 specimens from the Atlantic, Pacific and Indian Oceans. Cephalopods typically are active predators occupying a high trophic level (TL) and exhibit an ontogenetic increase in δ15N and TL. Our results, presenting the first global comparison for a deep-sea invertebrate, demonstrate that V. infernalis has an ontogenetic decrease in δ15N and TL, coupled with niche broadening. Juveniles are mobile zooplanktivores, while larger Vampyroteuthis are slow-swimming opportunistic consumers and ingest particulate organic matter. Vampyroteuthis infernalis occupies the same TL (3.0–4.3) over its global range and has a unique niche in deep-sea ecosystems. These traits have enabled the success and abundance of this relict species inhabiting the largest ecological realm on the planet.

Highlights

Despite its common name, the Vampire Squid, Vampyroteuthis infernalis Chun, 1903 (Cephalopoda, Vampyromorpha) is not a squid, but a unique animal with some traits common to those found in squids and others similar to those of octopods[8,9,10,11]
It is small compared to some other oceanic cephalopods, with a maximum reported mantle length (ML) of 210 mm[18], and is gelatinous in consistency
Most of these studies are based on limited data from Northern Hemisphere observations; its trophic ecology over its global range is not clear, and additional information obtained by other methods is required

Summary

Introduction

The Vampire Squid, Vampyroteuthis infernalis Chun, 1903 (Cephalopoda, Vampyromorpha) is not a squid, but a unique animal with some traits common to those found in squids and others similar to those of octopods[8,9,10,11]. While V. infernalis has usually been observed passively floating and collecting detritus and small planktonic organisms with the arm filaments[18], there are occasional observations and indirect suggestions based on stomach contents analysis corroborating the consumption of (pieces of) larger fast moving prey: crustaceans, squids and even fishes[8,18] The few regional SIA studies that include V. infernalis have found contradictory evidence regarding its habitat and trophic ecology (e.g. δ13C ranging from –21.0‰ to –17.0‰ and δ15N from 6.7‰ to 14.0‰ in specimens collected from different oceans37–39;Seibel et al, unpublished data). We propose the hypothesis that this ontogenetic increase in δ13C, δ15N and TL does not apply to V. infernalis due to their unique trophic ecology

Methods

Results

Conclusion