Ophiura ljungmani
Creators
- 1. Swedish Museum of Natural History, Dept. of Zoology, Box 50007, 10405 Stockholm, Sweden.
- 2. Museums Victoria, Sciences, GPO Box 666, Melbourne, Victoria 3000, Australia.
Description
Ophiura ljungmani (Lyman, 1878)
EAST ATLANTIC OCEAN • 1 specimen; off Ghana, Takoradi; 04°00’N, 001°43’W; 1445; 20 Nov. 1950; Galathea II stn. 33; grey clay; NHMD-868674 • 3 specimens; off Gabon; 02°00’N, 009°14’E; 1500–1520 m; 02 Dec. 1950; Galathea II stn. 63; blue clay; NHMD-305711.
NORTH ATLANTIC OCEAN • 1 specimen; off Iceland; 64°54,34’N, 029°58,39’W; 2005–2007 m; 25 Aug. 1996; BIOICE stn. 2914; SMNH-41981, SMNH-41982 • 1 specimen; off Iceland; 62 51,49°N, 014 41,65°W; 1729 m; 11 July 1997; BIOICE stn. 3067; SMNH-87642.
Remarks
This species strongly resembles the Atlantic Ophiura ljungman i (Lyman, 1878). They differ in the shape of the dorsal arm plates, which in O. spinicantha (Fig. 2A–E) are rectangular, proximally wider than long, but soon becoming longer than wide, with a notch in their distal edge, and hexagonal, with straight edges, at the distal end with slanted sides in O. ljungmani (Fig. 2F). The disc scalation is finer in O. spinicantha than in O. ljungmani and the oral shield is somewhat larger in proportion (Figs 2E; H). Both species usually have three arm spines (occasionally four), two small ones close together at the ventral end of the lateral arm plate, the third is placed widely spaced on the dorsal part of the lateral arm plate, up to twice as long as the ventral spines in O. ljungmani , but shorter than an arm segment. The holotype of O. spinicantha may have lacked the second small ventral spine or McKnight (2003) may have mistaken it for a tentacle scale, when he described O. spinicantha as having only two spines at a distance from each other. Both species also have scattered spines on the dorsal disc (Fig. 2G), which are often rubbed off in preserved material. Morphologically similar to these species is Ophiura bathybia H.L. Clark, 1911, known from the North Pacific, and which appears to have more disc spines than the other two species and the dorsal arm spine is longer than an arm segment (Fujita et al. 2009). Genetically these three species are distinct, but closely related (Christodoulou et al. 2019; O’Hara unpublished data). Ophiura ljungmani has the widest reported depth range of the three, with 101–4150 m (Paterson 1985), but we suspect that the few shallowest records may be misidentifications of another species (possibly Ophiura acervata (Lyman, 1869) or Ophiura fallax Cherbonnier, 1959). Ophiura spinicantha was found by Galathea II at 2470–4470 m (Table 1), but type material was collected as shallow as 1585 m (McKnight 2003), and O. bathybia is known from 2869–4425 m (Lambert & Austin 2007), but was not found by this study. Geographically, O. ljungmani has been reported from both eastern and western sides of the North Atlantic Ocean and to South Africa (found by Galathea II only off West Africa, Tables 1, 2), whereas O. spinicantha appears to be restricted to southern Australia and New Zealand (here found in the Tasman Sea and Kermadec Trench, Table 2), and O. bathybia occurs in the North Pacific from Japan to the high Arctic (Djakonov 1954; Lambert & Austin 2007, Fujita et al. 2009).
Notes
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Linked records
Additional details
Identifiers
Biodiversity
- Collection code
- EAST , NORTH
- Event date
- 1950-11-20 , 1996-08-25
- Family
- Ophiuridae
- Genus
- Ophiura
- Kingdom
- Animalia
- Order
- Ophiurida
- Phylum
- Echinodermata
- Scientific name authorship
- Lyman
- Species
- ljungmani
- Taxon rank
- species
- Verbatim event date
- 1950-11-20/12-02 , 1996-08-25
- Taxonomic concept label
- Ophiura ljungmani (Lyman, 1878) sec. Stöhr & O'Hara, 2021
References
- Lyman, T. (1878) Ophiuridae and Astrophytidae of the " Challenger " expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard, 5, 65 - 168.
- McKnight, D. (2003) New brittle-stars (Echinodermata: Ophiuroidea) from New Zealand waters. Zootaxa, 352 (1), 1 - 36. https: // doi. org / 10.11646 / zootaxa. 352.1.1
- Fujita, T., Iwasaki, U. & Okanishi, M. (2009) Ophiuroids (Echinodermata) of genus Ophiura collected from deep waters off Pacific coast of northern Japan. In: Fujita, T. (Ed.), Deep-sea Fauna and Pollutants off Pacific Coast of Northern Japan. National Museum of Nature and Science Monographs, Tokyo, 34, pp. 619 - 653.
- Christodoulou, M., O'Hara, T. D., Hugall, A. F. & Arbizu, P. M. (2019) Dark Ophiuroid Biodiversity in a Prospective Abyssal Mine Field. Current Biology, 29, 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012
- Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History), Zoology Series, 49, 1 - 162.
- Lambert, P. & Austin, W. C. (2007) Brittle Stars, Sea Urchins and Feather Stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum, 190 pp.
- Djakonov, A. M. (1954) 55 Ophiuroids of the USSR seas (English translation). Izdatel'stvo Akademii Nauk SSSR (Israel Program for Scientific Translations), Moscow / Leningrad (Jerusalem), 123 pp.