Annelid Fauna of the Prince Gustav Channel, a previously ice-covered seaway on the northeastern Antarctic Peninsula - Data

Study Extent

The annelid specimens examined in this study were collected using an Agassiz Trawl (AGT) during the expedition JR17003a on board the RRS James Clark Ross February–March 2018, which sampled the northern portion of the Prince Gustav Channel (PGC) situated on the northeastern tip of the Antarctic Peninsula. The three main sampling sites were as follows: (1) Duse Bay, a sheltered, glacier influenced bay located in the northwestern portion of the PGC; (2) PGC Mid, located in the main channel, including the second deepest basin of the PGC; (3) PGC South, the southernmost sample site, located in the main channel and including the deepest basin of the PGC. Three trawling depths (200 m, 500 m, 800/1000 m) were initially planned for each of the main sampling sites, with an additional deep 1200m trawl of the basin at PGC South. However, only at Duse Bay sites were all three trawling depths achieved, as 200m and 500m sites in the channel proper were too influenced by boulders to deploy the AGT. In total, six successful AGT deployments between depths of 204m and 1270m were carried out across the three sites and sorted on board for benthic fauna. In total In total, approximately 598 individual annelid specimens in roughly 57 morphospecies and at least 25 families were collected across all six AGT deployments

Sampling

The Agassiz Trawl (AGT) apparatus used comprised of a 1cm mesh with a mouth width of 2m, and once on the seabed was trawled at 1 knot for 5–10 minutes at each site. The AGT targeted macro- and megafaunal sized animals 1cm and larger, though with some smaller animals additionally captured in the sediment retained in trawls. A ‘cold-chain’ live sorting pipeline was followed on board, as outlined in detail in Glover et al. (2016). In summary, AGT sub-samples were carefully washed on 300-micron sieves in cold filtered seawater (CFSW), and annelid specimens were picked from sieve residue, cleaned and maintained in CFSW, and relaxed in Magnesium Chloride solution prior to specimen photography. Specimens were imaged using Canon EOS600D cameras either with 100mm Macro lens or through a Leica MZ7.5 microscope with SLR camera mount. Specimens were preliminary identified on-board to family level, numbered and recorded into a database, and fixed in 80% non-denatured ethanol. Samples that could not be fully sorted on board due to time restrictions were fixed in bulk for later sorting. All specimens were returned to the Natural History Museum London (NHM) and were re-examined using a Leica M216 stereomicroscope, and key morphological characters were imaged using a fitted Canon EOS600D camera. Specimens were identified to the best possible taxonomic level using original literature, specimen keys, and comparison with type specimen material from NHM collections. Where named species identifications were not possible, specimens were described as a morphospecies where the voucher number of a representative specimen is used as an informal species name for all specimens deemed to be the same species as the representative individual, e.g. Polynoidae sp. NHM_228. Where named species identifications were uncertain, the open nomenclature ‘cf.’ was used as a precautionary approach along with a representative voucher number, e.g. Antarctinoe cf. ferox NHM_232. Where specimens were fragmented, only fragments that clearly bore heads were counted and included in abundance records, as standard practice. Morphological taxonomic identifications are preliminary and will be updated following molecular investigations of these specimens using DNA barcoding. Glover, G. A., Dahlgren, G. T., Wiklund, H., Mohrbeck, I., and Smith, R. C. (2016). An End-to-End DNA Taxonomy Methodology for Benthic Biodiversity Survey in the Clarion-Clipperton Zone, Central Pacific Abyss. J. mar. sci. eng. 4. doi:10.3390/jmse4010002

Method steps

1. In addition to associated occurrence and collection data, specimen data generated following morphological identification steps outlined in the sampling description were assembled into a Microsoft Excel database using Darwin Core data standards.

Annelid specimens were identified to the best possible taxonomic level. Where named species identifications were not possible, specimens were described as a morphospecies where the voucher number of a representative specimen is used as an informal species name for all specimens deemed to be the same species as the representative individual, e.g. Polynoidae sp. NHM_228. Where named species identifications were uncertain, the open nomenclature ‘cf.’ was used as a precautionary approach along with a representative voucher number, e.g. Antarctinoe cf. ferox NHM_232.

1. Annelida
   rank: phylum
2. Polychaeta
   rank: class
3. Ampharetidae
   rank: family
4. Cirratulidae
   rank: family
5. Dorvilleidae
   rank: family
6. Flabelligeridae
   rank: family
7. Hesionidae
   rank: family
8. Lumbrineridae
   rank: family
9. Maldanidae
   rank: family
10. Myzostomidae
    rank: family
11. Nephtyidae
    rank: family
12. Opheliidae
    rank: family
13. Orbiniidae
    rank: family
14. Oweniidae
    rank: family
15. Paraonidae
    rank: family
16. Phyllodocidae
    rank: family
17. Polynoidae
    rank: family
18. Sabellidae
    rank: family
19. Scalibregmatidae
    rank: family
20. Serpulidae
    rank: family
21. Sternaspidae
    rank: family
22. Syllidae
    rank: family
23. Terebellidae
    rank: family
24. Tomopteridae
    rank: family
25. Travisiidae
    rank: family
26. Trichobranchidae
    rank: family
27. Aglaophamus
    rank: genus
28. Antarctinoe
    rank: genus
29. Antarctinoe
    rank: genus
30. Aphelochaeta
    rank: genus
31. Augeneria
    rank: genus
32. Austrolaenilla
    rank: genus
33. Barrukia
    rank: genus
34. Brada
    rank: genus
35. Chaetocirratulus
    rank: genus
36. Flabegraviera
    rank: genus
37. Harmothoe
    rank: genus
38. Leaena
    rank: genus
39. Leitoscoloplos
    rank: genus
40. Lumbriclymenella
    rank: genus
41. Maldane
    rank: genus
42. Myzostoma
    rank: genus
43. Ophelina
    rank: genus
44. Paranaitis
    rank: genus
45. Pionosyllis
    rank: genus
46. Pista
    rank: genus
47. Polyeunoa
    rank: genus
48. Protodorvillea
    rank: genus
49. Sternaspis
    rank: genus
50. Tomopteris
    rank: genus
51. Travisia kerguelensis
    rank: genus
52. Trypanosyllis
    rank: genus

Duse Bay and the Prince Gustav Channel, located on the northeastern tip of the Antarctic Peninsula