Polar Biology

, Volume 34, Issue 9, pp 1385–1397

A large new species of the genus Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae) from Antarctic seamounts

  • Marc Eléaume
  • Lenaïg G. Hemery
  • David A. Bowden
  • Michel Roux
Original Paper

Abstract

Ptilocrinus amezianeae n. sp. is a new species of stalked crinoid attributed to the family Hyocrinidae. Forty-five specimens were collected from seamounts north of the Ross Sea, and one specimen from the Kerguelen Plateau at depths ranging from 450 to 1,680 m. The collection from Admiralty and Scott seamounts constitutes the first example of a hyocrinid population known both from in situ photographs and from numerous collected specimens ranging from small juvenile to large adult. Variation in theca and stalk articulation characters throughout ontogeny is congruent with the molecular data and indicates that all the specimens examined belong to a single species. Tegmen and pinnule architecture, brachial arrangement, and stalk articular facets indicate that Ptilocrinus amezianeae n. sp. has close affinities with P. clarki and P. pinnatus from the northeastern Pacific and displays the most derived characters among these three species. Two cases of true arm division into two unequal branches suggest that Ptilocrinus and Calamocrinus are closely related. The picture and video transects on Admiralty seamount show a patchy distribution of living specimens with patches of mean density ca. 2.6 individuals m-2. In situ photographs also document predation by a sea urchin and a sea star on tegmen and proximal arms. The COI gene sequences analyzed in 25 specimens from Admiralty and Scott seamounts display low pairwise distances, low nucleotidic diversity, and intermediate haplotype diversity. These results, together with disarticulated ossicles and attachment disks observed on in situ photographs, indicate that the population investigated here is in decline.

Keywords

Echinodermata Stalked crinoids Hyocrinidae Ptilocrinus Antarctica Seamount Ross sea Kerguelen plateau 

Abbreviations

CAML

Census of Antarctic Marine Life

IPY

International Polar Year

NIWA

National Institute of Water and Atmospheric Research

MNHN

Muséum national d’Histoire naturelle

CCDB

Canadian Center for DNA Barcoding

Guelph

Biodiversity Institute of Ontario

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Marc Eléaume
    • 1
  • Lenaïg G. Hemery
    • 1
  • David A. Bowden
    • 2
  • Michel Roux
    • 1
  1. 1.Muséum national d’Histoire naturelle, Département Milieux et Peuplements Aquatiques, UMR7208-BOREA-MNHN/UPMC/IRDParis Cedex 05France
  2. 2.National Institute of Water and Atmospheric Research Ltd (NIWA)Kilbirnie, WellingtonNew Zealand

Personalised recommendations