Paranarthrura insignis Hansen 1913

Paranarthrura insignis Hansen, 1913

Fig. 7

Hansen (1913): 122–124; plate XII fig 3a–m. Stephensen (1932): 351.

Lang (1971b): 361, 367, 368–373, figs 3–5, plate 1a. Bird & Holdich (1989): 143–146, figs 1b, j, k, 2. Bamber (2000): 322–323; fig 4.

Guerrero-Kommritz et al (2002): 10.

Guerrero-Kommritz (2003): 3.

Larsen (2005): 121, 140.

c.f. Paranarthrura insignis: Larsen (2005): 129–130 – probably not P. insignis Hansen, 1913.

Identification reference. Hansen (1913), Lang (1971b), Bird & Holdich (1989).

Distribution records from the AFEN, BIOICE & BIOFAR surveys. Recorded from twelve AFEN samples, from the Wyville-Thomson Ridge, North Rockall Trough, Barra Fan, and Hebrides Slope, at depths 888–2046m; 28 BIOICE samples, from the Denmark Strait, Greenland-Iceland Rise, Iceland Basin, and Irminger Basin, at depths 385–2296 m. No records from the BIOFAR survey. The highest count was 122 specimens from BIOICE sample 3282, Iceland Basin, at 1811 m.

Distribution elsewhere. Davis Strait, 582–2193 m (Hansen op.cit.); Feni Ridge and Hebrides Slope to the South Biscay Slope, 641–4829 m (Bird & Holdich 1989); also Ibero-Moroccan Gulf, 1523 m (BALGIM survey, Bird ined.). Further afield, P. insignis has been recorded from the Angola Basin 1038–1300 m (Bamber 2000, Guerrero-Kommritz 2003), Gulf of Alaska and Aleutian Trench, 2340–5000 m (Kudinova-Pasternak 1973) and abyssal Caribbean, 4550–4690 m (Kudinova-Pasternak & Pasternak 1978), but see remarks below.

Remarks. Angolan specimens examined by Bamber (2000) were shown to have a very distinctive sinuous inferior margin on the cheliped propodus and fixed finger. It was commented that this feature, mentioned by Hansen (op.cit.) was not shown by Lang (1971b) or Bird & Holdich (1989). This is not wholly correct and both references show the ‘three-lobed’ feature, albeit weakly. Lang’s figure was derived from Hansen’s type material so it is almost certainly accurate. Additional drawings of an allometric series are added here (Fig. 7).

It is ostensibly a very widely distributed agathotanaid but several other species with two-articled uropod endopods have been described, the last being Paranarthrura angolensis Guerrero-Kommritz, Schmidt & Brandt, 2002, and it is possible that other ‘ insignis -like’ species may be discovered. Similarly, some Pacific Ocean records of this species may well be attributable to other species, c.f. Paranarthrura vitjazi (Larsen 2007)