Figure 1.
Map showing the five geographic regions where colonies of the sea pens Anthoptilum grandiflorum and Halipteris finmarchica were collected along the continental slope.
LC: Laurentian Channel, GB: Grand Banks, FC: Flemish Cap, NNL: North Newfoundland, LB: Labrador.
Table 1.
Number of colonies sampled in the different geographic regions.
Figure 2.
Associates of Anthoptilum grandiflorum: (A) decapod larva, (B) unidentified sp. 3, (C) unidentified sp. 1, (D) unidentified sp. 4, (E) unidentified sp. 2, (F) unidentified copepod.
Unidentified sp. 1 to 4 correspond to potential egg mass. Associates of Halipteris finmarchica: (G) unidentified Lamippidae, (H and I) unidentified sp. 7. Scale bar in A = 200 µm, B, F and H = 500 µm, C and D = 2 mm, E = 4 mm, I = 100 µm. Species numbers linked to Table 2.
Figure 3.
Lamippe bouligandi, a parasitic copepod living inside the polyps of Anthoptilum grandiflorum: (A) in situ view of the copepod (arrow) through the transparent polyp wall, (B) a female, (C) a male.
Scale bar in A = 1 mm, in B = 500 µm and in D = 100 µm.
Figure 4.
The sea anemone Stephanauge nexilis using the central axis of Halipteris finmarchica as a substrate: (A) general view of a colony of H. finmarchica harbouring two sea anemones in the upper section, (B) a small sea anemone surrounded by sea pen tissues, (C) dorsal view of the sea anemone found on the upper section of the sea pen colony.
Gastro-vascular contents were found: (D and F) amphipod, (E) mix of prey including amphipods, halocyprids, egg mass, and unidentified food item extracted from one sea anemone. sa: sea anemone, ca: central axis, spt: sea pen soft tissues. Scale bar in A = 2 cm, in B and D = 2 mm and C and F = 1 cm, E = 1 mm.
Figure 5.
Undescribed copepod species belonging to Corallovexiidae living inside the polyps of Halipteris finmarchica: (A) row of polyps including a polyp infested with a copepod (arrow), (B) female copepod, (C) male copepod and (D) nauplius larvae.
Scale in A = 1 mm, in B = 500 µm, in C and D = 100 µm.
Table 2.
Species found on the sea pens Anthoptilum grandiflorum and Halipteris finmarchica during the present study (2006–2007).
Figure 6.
Rarefaction curves for Anthoptilum grandiflorum (left panels) and Halipteris finmarchica (right panels), based on close associates only (top two panels) or all associates in spring and fall (bottom four panels).
(A) Close associates of A. grandiflorum; (B) all the associated fauna of A. grandiflorum in the fall and (C) in spring/summer. (D) Close associates of H. finmarchica; (E) all the associated fauna of H. finmarchica in the fall and (F) in spring/summer. LC: Laurentian Channel, GB: Grand Banks, FC: Flemish Cap, NNL: North Newfoundland, LB: Labrador.
Figure 7.
Principal component analyses and biplots based on the associated species of Anthoptilum grandiflorum (A, B) and Halipteris finmarchica (C, D).
Green up triangle: spring; yellow circle: summer; blue down triangle: fall; black square: winter.
Table 3.
Influence of increasing depth on total mean yield (MEYtot) of all associates on colonies of Anthoptilum grandiflorum and Halipteris finmarchica in the different geographic regions (only sites with more than 10 colonies harbouring associated species were used).
Table 4.
Prevalence of associates on colonies of Anthoptilum grandiflorum and Halipteris finmarchica in the different geographic regions (as percent colonies harbouring them).
Figure 8.
Stable isotope values (δ15N and δ13C) for sea pens (Ag: Anthoptilum grandiflorum and Hf: Halipteris finmarchica) and their associated species (Lb: Lamippe bouligandi, Sn: Stephanauge nexilis and Uc: undescribed Corallovexiidae).
To locate and compare the signature of the sea pens, values for other invertebrates are shown, Am: Amphipods, Eu: Euphausiids, Pm: Pasiphae multidentata, Pb: Pandalus borealis and Sc: snow crab from Sherwood & Ross [42], as well as sedimentary organic matter (SOM) from Muzuka & Hillaire-Marcel [41]. Result shown as mean ± SE (n = 2–5). Black: A. grandiflorum and its associates, Blue: H. finmarchica and this associates, Grey: other invertebrates and SOM.
Table 5.
Carbon and nitrogen stable isotope signatures (δ13C and δ15N), and trophic level (TL) of Anthoptilum grandiflorum and Halipteris finmarchica and their dominant associates.