Pholoe longa, Malmgren, 1865

PHOLOE LONGA View in CoL (O.F. MULLER €, 1776)

FIGS 1 – 4

Aphrodita longa O.F. M uller €, 1776: 218; Fabricius, 1780: 313 – 314.

Pholoe longa Malmgren, 1865: 89 View in CoL , pl. XI, fig. 13a – c (part); Pettibone, 1992: 4 – 6, fig. 1 a – j (part).

Pholoe minuta Pettibone, 1954: 229 – 231 View in CoL , fig. 26f. (part).

Neotype: Near Ilulissat: 69 ° 29.766N, 50 ° 38.520W, depth 6 – 8 m, 6 June 2009, formalin, complete specimen (ZMUC-POL-2404).

Non-type material: North Atlantic Ocean , Western Greenland: Bay NW of Dundas: 76 ° 34 0 0 ″ N 68 ° 50 0 12 ″ W, 14-Aug-1982, depth 13 m, clay, sand, formalin, 1 af (ZMUC-POL-2363); Tasiusak , N of Upernavik: 73 ° 22 0 54.72 ″ N 55 ° 58 0 58.92 ″ W, 13-Aug-1931, depth 10 – 18 m, formalin, 1 complete, 6 af (ZMUC-POL-2377); E Upernavik , Harbour : 72 ° 47 0 20.43 ″ N 56 ° 08 0 54.71 ″ W, 17-Jun-1936, depth 24 m, sand, formalin, 1 af (ZMUC-POL-2373); Upernavik, Harbour: 72 ° 39 0 00.13 ″ N 56 ° 02 0 01.88 ″ W, 05-Jul-1936, depth 22 m, sand, formalin: 1 complete, 3 af ( ZMUC- POL-2371), 3 af (ZMUC-POL-2372), depth 13 m, 3 af (ZMUC-POL-2365), depth 24 m, 3 complete, 14 af (ZMUC-POL-2368), depth 34 m, 1 complete ( ZMUC- POL-2376), depth 10 – 30 m, 2 af ( USNM 62044 About USNM ) GoogleMaps ; Kronprinsens Ejland , Disko Bay: 69 ° N 53 ° 22 0 W, 20- Jul-1978, depth 6 m, sand, formalin, 6 af ( ZMUC- POL-2369) GoogleMaps ; near Ilulissat : 69 ° 29.766N 50 ° 38.520W, depth 6 – 8 m, 6-Jun-2009, formalin, 27 af ( SMF 24089 About SMF ) GoogleMaps ; same area, depth about 15 m, formalin, 2 af ( ZSRO-P2396 ) ; 69 ° 20.624N 50 ° 54.985W, depth 6 – 8 m, mixed sediment, 6-Jun-2009, formalin: 6 complete, 1 af ( ZMH-P 27776 ) GoogleMaps , many specimens ( ZSRO-P2393 ) , 1 af ( ZMH-P 27772 ) , 1 af ( ZMH-P 27773 ) , 18 af ( ZSRO-P2399 ) , 96% ethanol, 40 af ( ZSRO-P2383 ) ; 69 ° 15.249N 51 ° 2.822W, eulittoral, 5- Jun-2009, formalin: 2 af ( ZSRO-P2389 ) GoogleMaps , 3 af ( SMF 24090 About SMF ) ; Godhavn , 69 ° 14 0 50 ″ N 53 ° 32 0 W, 19-Jul-1977, depth 50 m, coarse gravel with clay, formalin, 2 juveniles, 18 af ( USNM 62046 About USNM ) GoogleMaps ; Lyngmarksbugt , Godhavn, 69 ° 14 0 58 ″ N 53 ° 34 0 06 ″ W, 28-Aug-1959, depth 35 – 38 m, clay, mud, detritus, formalin, 7 af ( USNM 62045 About USNM ) GoogleMaps ; Jacobshavn (Ilulissat): south of airfield: 69 ° 14.1372N 51 ° 4.2492W, eulittoral, mud, influenced by meltwater, 8-Jun-2009, 96% ethanol, 1 af ( SMF 24088 About SMF ) GoogleMaps ; 69 ° 13 0 18 ″ N 51 ° 06 0 55 ″ W, 7-Aug-1870, depth 64 m, clay, formalin, 2 af ( USNM 59928 About USNM ) GoogleMaps ; Aasiaat (Egedesminde): 68 ° 42 0 38.03 ″ N 52 ° 52 0 19 ″ W, 20-October-1890, formalin: 4 complete, 8 af ( ZMUC- POL-2366), 4 af ( USNM 62041 About USNM ) GoogleMaps , year 1891, 56 specimen (ZMUC-POL-2367), year 1892, 6 af ( USNM 62042 About USNM ) ; Nordre Stromfjord : 67 ° 32 0 N 52 ° 30 0 W, year 1911, depth 21 – 41 m, formalin, 1 complete, 2 af (ZMUC-POL-2370) GoogleMaps ; Nuuk (Godthab): 64 ° 10 0 30.05 ″ N 51 ° 45 0 03.42 ″ W, 01-Sep-1953, depth 9 m, sand, formalin, 2 af (ZMUC-POL-2364) GoogleMaps ; near Paamiut : 62 ° 0.709N 49 ° 41.208W, eulittoral, 12-Jun-2009, sand between stones, gravel, macrophyta, formalin, 1 complete ( ZSRO-P2391 ) GoogleMaps ; Bredefjord : 60 ° 54 0 59 ″ N 46 ° 22 0 15 ″ W, 26-Aug-1912, gravel with dead algae, depth 10 – 15 m, formalin: 5 af (ZMUC-POL-2374), 1 af (ZMUC-POL-2375), 1 complete ( USNM 62043 About USNM ) GoogleMaps .

Diagnosis: Specimens white with no pigment discernible; mid-dorsum not completely covered by elytra; elytral papillae usually articulated; facial tubercle present; lateral antenna absent; notopodium with short row of large simple papillae along its anterior and posterior edge, neuropodium with several terminal papillae (stylodes); neurochaetae heterogomph compound chaetae with distinctly serrated blades.

Description: Neotype complete specimen (fragmented into two parts) with 47 chaetigers, about 10.6 mm in length and 1.7 mm wide. Examined specimens 6.2 – 16.3 mm long and 0.9 – 2.5 mm wide; specimen with most chaetigers, 77 chaetigers, 27.6 mm long, 2.1 mm wide. Body short, linear, depressed; ventral surface papillate with longitudinal groove. Mid-dorsum not covered by elytra ( Figs 1A, 2A View Figure 2 , 3A – B View Figure 3 ). First pair of elytra rounded ( Figs 1A, E, 3B View Figure 3 , 4C View Figure 4 ), in succeeding segments reniform ( Figs 1B, F – H, 4D View Figure 4 ), in posterior segments becoming rounded again; segments without elytra with nodular lobes in the position of elytrophores; each elytron with short marginal papillae, also some papillae distributed over the dorsal elytral surface, in particular in anterior elytra ( Fig. 1A, B, E – H); elytral papillae usually articulated ( Figs 2D, E View Figure 2 , 3C, D View Figure 3 ), in posterior segments with broad base and long, articulated, thin tip; elytral surface without pigment ( Fig. 3A View Figure 3 ).

Prostomium with smooth, distally tapering median antenna without articulations ( Figs 1B, 2B View Figure 2 , 3B View Figure 3 ); lateral antenna absent; with two pairs of closely set, black eyes, sometimes anterior and posterior pair of eyes fused. Facial tubercle distinct, located below the median antenna and above the mouth ( Figs 1B, 2A, B View Figure 2 , 3B View Figure 3 ). Tentacular segment achaetous, with two pairs of tentacular cirri rising from a tentaculophore, dorsal and ventral tentacular cirrus cirriform with few simple papillae ( Figs 1B, 2B View Figure 2 ). Palps massive, tapering ( Figs 1B, 2B View Figure 2 ).

Parapodia biramous, proximoventrally with numerous simple short papillae ( Figs 1C, D, 4A, B View Figure 4 ); notopodium short, of conical shape at the end, without distinct terminal papillae, row of large simple papillae along its anterior and posterior edge ( Figs 1C, D, 4A, B View Figure 4 ); neuropodium tapering, longer than notopodium, with numerous simple papillae mainly anteriorly and ventrally distributed over the surface, also several terminal papillae (stylodes) present ( Figs 1C, D, 4A, B View Figure 4 ); cirriform ventral cirrus present on neuropodia, ventral cirrus almost doubled in size and anteriorly oriented at first chaetiger (the so-called buccal cirrus), otherwise laterally oriented. Both podial lobes bearing single stout aciculae that penetrate epidermis ( Fig. 1C, D); notopodium with long, spinous capillaries and short, geniculate, spinous capillaries ( Figs 1J, L, 2H, I View Figure 2 ); neurochaetae compound falcigerous, heterogomph chaetae with distinct serrations of the blade and fine serrations at the tip of the shaft ( Figs 1K, 2G View Figure 2 , 3C View Figure 3 ); blade length variable, usually longest in superior neurochaetae and shortest in inferior neurochaetae.

Pygidium with pair of cirriform anal cirri ( Fig. 1I), anus dorsal.

Pigmentation: Specimens white with no pigment discernible ( Fig. 3 View Figure 3 ); sometimes with ‘rusty’, orange-coloured cover on the elytra that can be brushed off.

Biology: Specimens from station 28 (collected on 6 June 2009, north of Ilulissat) ovigerous. Eggs ovoid, 100 – 155 lm long, about 80 – 100 lm wide.

Geographical distribution (assessment based on molecular data, see following chapters of the present paper): All along the west coast of Greenland; Canada, in Bay of Fundy, Hudson Bay, and Resolute Bay; Bering Sea (Alaska).

Remarks: The designated neotype was not collected at the presumed type locality as material from this exact location was not in very good condition. We selected a well-preserved complete specimen from another sampling location in West Greenland. Pholoe longa is large in comparison with other Pholoe spp. from the North Atlantic or the North Pacific. It is characterized by its white appearance, the absence of pigment on the prostomium or other parts of the body, the absence of lateral antenna, a mid-dorsum uncovered by the elytra, articulated elytral papillae, a notopodium with a short row of large simple papillae along its anterior and posterior edge, a neuropodium with several terminal papillae (stylodes), distinctly serrated blades of the compound neurochaetae, and the presence of a facial tubercle. The latter is usually easily seen if specimens are stained with methyl green; problems to detect it have only been encountered when the pharynx was everted.

The material that the redescription of P. longa by Pettibone (1992) was based upon has been examined in the course of the present study and its identity was confirmed; however, the description provided by the author was incorrect in parts. Most importantly, the presence of lateral antenna could not be confirmed and the size of the facial tubercle is incorrectly reflected in the illustrations. Relying on the correct labelling of the vials of lot USNM 06046, the specimens illustrated by Pettibone (1992) are recognized as juveniles. The presence of the lateral antenna in P. longa was quoted in succeeding publications (e.g. Jirkov, 2001; Padovanni & Amaral, 2013), but is incorrect.