Bathyglycinde profunda (Hartman & Fauchald, 1971)

Bathyglycinde profunda (Hartman & Fauchald, 1971) View in CoL

( Figs 9A–G View Figure 9 , 10G View Figure 10 )

Glycinde profunda Hartman and Fauchald, 1971: 74 View in CoL , pl. 4, figs c–e.

Bathyglycinde profunda Rizzo and Amaral, 2004b: 938–942 View in CoL , figs 1–15,16–21, table1.–Böggemann,2005: 189–193,figs 111, 112. – Böggemann 2009: 308–311, figs 41–43, 47. – Fiege et al. 2010: appendix, tables 3 and 5 (name only). – Moreira and Parapar 2015: 58–60, figs 24A–R. – Böggemann 2016: 236– 237, figs 8, 11. – Böggemann & Sobczyk in Gunton et al. 2021: 47 fig.11, B, D, E.

Material examined: CentralAtlanticOcean, Mid-Atlantic Ridge, West, SO 237 (VEMA-Transit), station 9-8, 5004 m ( ZMH-P 26696); station 11-4, 5112 m ( ZMH-P 26698); Mid-Atlantic Ridge, Central, SO 237 (VEMA-Transit), station 8-4, 5176 m ( SMF 30493, SMF 30494, ZMH-P 26695, ( SMF 30589, SEM 1318 + 1319: 33 uniramous parapodia). SE Pacific Ocean, Peru Basin ( DISCOL area), SO 242 ( JPIO-DISCOL 1), station 93-5, 4185 m ( SMF 30496: 29 uniramous parapodia); station 126-9, 4257 m ( SMF 30495: 31 uniramous parapodia). – for details and additional specimens see the Supporting Information, Table S2 View Table 2 .

Measurements for largest specimens studied: central Atlantic (SMF 30589): length 14.2 mm, width 0.5 mm (excl. parapodia), 55 chaetigers; Peru Basin, Pacific (SMF 30496): length 7.5 mm, width 0.3 mm (excl. parapodia), 31 chaetigers.

Description: Prostomium much longer than wide, smooth, indistinctly annulated (ca. 10 rings) ( Fig. 9A, B View Figure 9 ), two longitudinal lateral grooves on each side, terminal annulus with bi-articulate appendages. Eyes absent. Proboscis with papillae of different types arranged in longitudinal rows of different areas (I–VI). Area I: short oval to rounded, pointed, II: II-1 short, bifid to tridentate, II-2–6 elongate, decreasing in length and tip less bent, uni and bidentate ( Fig. 10G View Figure 10 ).

Parapodia increasing in length from anterior to posterior. Anterior uniramous chaetigers with one digitiform prechaetal and one shorter, triangular postchaetal lobe.Dorsal cirri inserted at parapodial base, foliaceous, slightly shorter than prechaetal lobe, ventral cirri about same length, digitiform ( Fig. 9C View Figure 9 ); 29–33 uniramous chaetigers, notopodia reduced; following parapodia biramous, notopodia with digitiform prechaetal lobe, smaller than slender triangular neuropodial prechaetal lobe ( Fig. 9D View Figure 9 ). Notopodia with simple capillaries with pointed tips ( Fig. 9E View Figure 9 ). Neuropodia with heterogomph compound spinigers with long, finely serrated blades, increasing in length towards center of fascicle ( Fig. 9F View Figure 9 ). Pygidium short, rounded ( Fig. 9G View Figure 9 ).

Remarks: The specimens studied from the central Atlantic and the Peru Basin agree well with the description published by Böggemann (2005). The number of anterior uniramous parapodia varies among specimens and lower numbers (29/31) were found in specimens from the Peru Basin studied here than in those reported earlier by Rizzo and Amaral (2004b) and)

Böggemann (2005, 2009) for specimens from the South Atlantic. Rizzo and Amaral (2004b) reported slightly higher numbers of uniramous parapodia for specimens originating from the equatorial region of the Atlantic and lower numbers for Brazilian specimens. Morphological details of proboscidial papillae differ slightly between Rizzo and Amaral (2004b) and Böggemann (2005) and our limited observations, which is probably due to different points of inspection along the proboscis. Bathyglycinde profunda was originally described from abyssal depths of 2862–5023 m (type locality 4800 m) in the Atlantic north of Bermuda (Hartman and Fauchald 1971) but our morphological and molecular data, as well as those of Böggemann (2009) and morphological data of Gunton et al. (2021), suggest it is a widespread deep-water species occuring not only in the Atlantic, but also in the Central, Southern, and Eastern Pacific Ocean. Gunton et al. (2021) reported it as one of only two species occurring all along the east coast of Australia from the Coral Sea Marine Park and off Fraser Island in the north to Flinders and Freycinet Marine Parks in the south, i.e. covering a distance of more than 1900 km. However, the species has to date not been recorded in faunal studies from the NW Pacific (Böggemann 2005, Alalykina 2020) and the Atlantic Sector of the Southern Ocean (Böggemann and Dietz 2016).

Molecular data confirm and extend the distribution of Bathyglycinde profunda for the Atlantic ( Guinea and Cape Basin (s. Böggemann 2005) and the Central Atlantic) and the Central and Eastern Pacific (Clarion Clipperton Fracture Zone (s. Janssen et al. 2019) and Peru Basin) ( Fig. 2 View Figure 2 ).

Distribution: Central and Eastern Pacific [1400–4900 m, Böggemann 2005; 4127–5023, Janssen et al. (2019); 4127– 4257 m, this study], SE Pacific off Eastern Australia [2093–4280 m, Gunton et al. (2021)], Southern Ocean off Southern Australia [2063 m, MacIntosh et al. (2018)], NW Atlantic [1000–5023 m, Böggemann 2005], NE Atlantic [2400–5500 m, Böggemann 2005], W Atlantic [630–3783 m, Böggemann 2005], E Atlantic [5389–5450 m, Böggemann 2005], Central Atlantic (Vema Fracture Zone: 5004–5176 m, this study), SE Atlantic [Cape, Angola, and Guinea Basin: 3961–5494 m, Böggemann (2009)], SW Atlantic [350–5189 m, Böggemann 2005, 2016)].