Biodiversity Data Journal :
Taxonomic Paper
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Corresponding author: Naoto Jimi (beniimo7010@gmail.com)
Academic editor: Sarah Faulwetter
Received: 16 Apr 2020 | Accepted: 27 May 2020 | Published: 08 Jun 2020
© 2020 Naoto Jimi, Akito Ogawa, Shimpei Hiruta, Minoru Ikehara, Satoshi Imura
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Jimi N, Ogawa A, Hiruta SF, Ikehara M, Imura S (2020) A new deep-sea species of Flabelligena from off the South Orkney Islands, the Southern Ocean. Biodiversity Data Journal 8: e53312. https://doi.org/10.3897/BDJ.8.e53312
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A new acrocirrid species, Flabelligena hakuhoae sp. nov., is described from off the South Orkney Islands, the Southern Ocean. Individuals of the new species were collected by rock dredging, 2036–2479 m in depth.
The new species can be distinguished from its congeners by the number of branchiae, position and length of paired ventral large papillae and length of body papillae.
Antarctica, Southern Ocean, Polychaeta, Hakuho maru
Acrocirridae Banse, 1969 (clade Cirratuliformia) consists of 43 species in nine genera distributed from the intertidal zone to the deep seafloor (
Flabelligena Gillet, 2001 belongs to the Acrocirridae. It has a minute body, body papillae, spinulose or serrated (not cross-barred) notochaetae, 1–3 pairs of branchiae and a pair of frontal palps (
During the research cruise KH19-06-Leg4 by R/V Hakuho maru, the first author found individuals of Flabelligena from off the South Orkney Islands. In this paper, we describe the specimens as a new species.
Specimens were collected from off the South Orkney Islands (Fig.
Sampling sites and sediments of the type locality. A. Type localities of three Flabelligena species from the southern hemisphere: red star, F. hakuhoae sp. nov. in this study; blue circle, F. erratica in Orensanz (1974); yellow triangle, F. amoureuxi in Gillet (2001); B. The collection gear after sampling at the type locality (red star in A), off the South Orkney Islands, the Southern Ocean.
We followed the morphological terminology of
Holotype (NSMT-Pol H-813) 1.8 cm long, 1 mm wide (without chaetae, at widest chaetiger) for 27 chaetigers (incomplete). Body cylindrical (Fig.
Flabelligena hakuhoae sp. nov., holotype (NSMT-Pol H-813). A. Anterior end, dorsal view; B. anterior end, ventral view, arrows indicate ventral papillae; C. anterior end, dorsal enlarged view, an arrow head indicates a branchia; D. ventral large papilla, enlarged view. Scale bars: A–B, 500 μm; C, 125 μm; D, 50 μm.
Flabelligena hakuhoae sp. nov., paratype (ICHUM-6113), scanning electron micrographs. A. Anterior end, frontal view, proboscis is not everted; B. Anterior end, dorsal side, frontal view; C. Anterior end, ventral side, frontal view; D. Anterior end, lateral view; E. branchial scars and nephridial lobe, enlarged view; F. pygidium, dorsal view. Asterisks indicate branchial scars. Arrow heads indicate papillae around branchial scars. Abbreviations: nl, nephridial lobe; p, palp; ps, palp scar. Scale bars: A, 300 μm; B–D, 200 μm; E 100 μm; F, 200 μm.
Prostomium subtriangular, eyes absent, nuchal organs absent. Peristomium distinct. Palp scars on anterior margin of prostomium, one pair (Figs
Paratype (ICHUM-6113, used in SEM observation) 1.2 cm in length, 0.9 mm in width (without chaetae, at widest chaetiger), 23 chaetigers. Pygidium rounded (Fig.
The species is named after the R/V Hakuho-maru, a gear of the ship which collected the type specimens from the Southern Ocean. The specific name is a noun in the genitive case.
The new species is only known from the type locality, off the South Orkney Islands, the Southern Ocean (
Flabelligena hakuhoae sp. nov. belongs to Flabelligena because it has the following features: retractile anterior region, absence of distinct body region, presence of various pairs of branchiae, composite falcigerous neurochaetae, simple spinulose or serrated notochaetae (
A comparative table of Flabelligena (modified from
F. cirrata |
F. amoureuxi |
F. erratica |
F. biscayensis |
F. mediterranea |
F. gascognensis |
F. hakuhoae sp. nov. This study |
|
Pair of branchiae |
1 |
1 |
1 |
2 |
2 |
3 |
3 |
Pair of ventral large papillae |
absent |
absent |
one pair, between chaetigers 6–7 |
absent |
one pair, between chaetigers 4–5 |
one pair, between chaetigers 6–7 |
one pair, ventral side of parapodium in chaetiger 6 |
Chaetigers |
17–24 |
30 |
20–30 |
incomplete (11) |
incomplete (8) |
incomplete (25) |
23–? |
Notochaetae |
serrated 1–2 |
spinulose 1 |
spinulose 1 |
spinulose 2–5 |
spinulose 2–5 |
spinulose ?–4 |
spinulose 1–2 |
Neurochaetae |
composite 4–8 |
composite 3–5 |
composite 1–3 |
composite 1 |
composite 2–4 |
composite 2–4 |
composite 1–4 |
Eyes |
0 |
0 |
2 |
0 |
0 |
0 |
0 |
Papillae between noto- and neurochaetae |
short, 2/9 of neurochaetae |
short, 4/15 of neurochaetae |
short, 3/8 of neurochaeta |
long, as long as neurochaetae |
long, as long as neurochaetae |
long, as long as neurochaetae |
short, 1/6 of neurochaetae |
Type locality |
New England (NW Atlantic) |
Crozet Islands (Indian Ocean) |
Argentina (SW Atlantic) |
Bay of Biscay (NE Atlantic) |
Mediterranean Sea |
Bay of Biscay (NE Atlantic) |
off the South Orkney Islands (Southern Ocean) |
Depth (m) |
466–530 |
215–980 |
288 |
2210 |
4690 |
545–1113 |
2036–2479 |
We thank the captain and crew of the R/V Hakuho-maru, Dr. Kenichiro Tani and the scientific team of KH19-06-Leg4 cruise. We also thank the members of Department of Biodiversity Ia, Hokkaido University for facilitating SEM observation. This study was partly supported by JSPS KAKENHI No. 19J00160. Drs. Alexandra Rizzo, Sergio I. Salazar-Vallejo and an anonymous reviewer provided valuable comments for this manuscript.