Flabegraviera profunda, Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, Revision of Flabelligera Sars, 1829 (Polychaeta: Flabelligeridae) 3203, Zootaxa 3203 (1), pp. 1-64 : 45-46

Flabegraviera profunda n. sp.

Figure 19

Flabelligera mundata: Gravier 1911:110–112 , Pl. 8, Fig. 87 (partim); Ehlers 1913:535–537, Pl. 41, Figs. 1–12 (partim); Benham 1927:129 (partim); Monro 1939:130 (partim) (non Gravier).

Type material. Antarctic Ocean. Holotype ( USNM-26611 ) and five paratypes ( USNM unumb.), R/ V Eastwind 1966, Stat. 43B (62°08.7' S, 57°49' W), off North of Trinity Peninsula , Graham Land, 225–185 fathoms, Pawson & Squires coll., 11 Feb. 1966 (complete paratypes measured).

Additional material. Two specimens ( BMNH- 1928.2.20.195/96), McMurdo Sound, 5 mi N Inaccessible Island, R/V Terra Nova, Stat. 314, 222–241 fathoms, mud (damaged, flat, most chaetae broken; one with two parasitic copepods, one with a globose, slightly curved, 4.5 mm long egg mass, with a short peduncle). Two specimens ( BMNH- 1928.2.29.198/199), off Cape Bird Peninsula, McMurdo Sound, R/V Terra Nova, Stat. 331, 250 fathoms, mud (damaged, depressed). One specimen ( ZMH- 24498), dried-out, Cruise ANT XV-3, R/V Polarstern, Weddell Sea, Cape Norwegia, St. 48-220 (70°48.2' S, 10°41.5' W), 509 m, 19 Feb. 1998, B. Hilbig, coll. Two specimens ( ZMH- 24499), dried-out, probably belonging to this species, Cruise ANT XV-3, R/V Polarstern, South of Vestkapp, St. 48-88 (73°28.5' S, 22°30.0' W), Weddell Sea, 1681 m, AGT, det & leg Brigitte Hilbig 4.2.1998.

Description. Holotype complete (USNM-26611), slightly damaged with some broken notochaetal bundles ( Fig. 19A ); body fusiform, posteriorly tapering, slightly depressed; 70 mm long, 11.5 mm wide, cephalic cage 8 mm long (chaetae not exposed), 36 chaetigers. Tunic papillated, surface irregular ( Fig. 19B ) dorsally and ventrally, with a thin layer of fine sediment particles and epizoans; papillae long, distally fusiform, clavate, forming a sheath around chaetae; papillae thinner in notochaetal than in neurochaetal shafts.

Cephalic hood not exposed. Anterior end observed in a paratype. Prostomium low cone; eyes not visible. Caruncle well developed, with two thick longitudinal keels and shallow central area separating branchial plate into two lateral portions ( Fig. 19C ). Palps long, tapering distally; palp bases large, round. Dorsal and lateral lips well developed, ventral lip reduced. Branchiae arranged in 6–7 rows of about 120 filaments per side, decreasing in size ventrally. Nephridial lobes pale, base conical, tips broken.

Cephalic cage chaetae about 1/10 body length or 7/10 body width. Chaetiger 1 involved in cephalic cage, with 46 noto- and 34 neurochaetae. Anterior dorsal margin of chaetiger 1 smooth. Anterior chaetigers without especially long papillae. Chaetigers 1–3 of about same length. Chaetal transition from cephalic cage chaetae to body chaetae abrupt; neurohooks from chaetiger 2. Gonopodial lobes not seen.

Parapodia well developed, completely covered by lateral tunic ( Fig. 19D ). Median neuropodia ventrolateral. Notopodia apparently arranged in groups with successive descending alignment but due to the body softness details cannot be observed. Noto- and neuropodia widely separated.

Median notochaetae arranged inside a long cylinder completely covering chaetal length but eroded in many chaetigers. All notochaetae smooth, about twice as long as body width, 4–5 per fascicle, articulations weakly defined distally, if at all. Neurochaetae multiarticulated capillaries in chaetiger 1; very long, anchylosed neurohooks from chaetiger 2, arranged in a cylindrical chaetal shaft ( Fig. 19E ), 3–4 per fascicle; small paratypes with multiarticulated neurohooks with 1–3 median articles. Crest bending region anchylosed in holotype, slightly visible in small paratypes ( Fig. 19F ), the latter with width:length ratio 1:7.

Posterior end exposed, truncate; pygidium with anus terminal, without anal cirri. Some specimens from deeper water (BMNH) with pigmented anus. One specimen (BMNH-1928.2.20.195/96) with two parasitic copepods, one with a globose, slightly curved, 4.5 mm long egg mass, with a short peduncle.

Etymology. The specific name is derived from the Latin word profund, meaning deep, to emphasize that this species was collected in deeper water, in comparison to the previous species.

Remarks. Flabegraviera profunda n. sp. closely resembles F. mundata because both have thick tunics, very short cephalic cage chaetae, very long notochaetae, and up to four neurohooks per bundle. They differ, however, because in F. profunda n. sp. the neurohooks are mostly anchylosed, with the crest bending section not visible, as if they were simple, not multiarticulated; only the smallest falcigers or those present in smaller paratypes include 1–2 multiarticulated neurohooks, but even there, the crest bending section is poorly developed. In F. mundata , however, all neurohooks are multiarticulated. Further, the tunic is markedly coated with fine sediment particles in F. profunda n. sp. while it is mostly without sediment particles in F. mundata .

These two species apparently live in different environments: F. profunda n. sp. is found in deep water, probably in muddy bottoms (as indicated by gut contents and sediment cover), whereas F. mundata is found in shallower water in rocky or mixed bottoms.

Type locality. Off Trinity Peninsula , Graham Land, Antarctica .

Distribution. McMurdo Sound and Weddell Sea, Antarctica, in deep water (330–450 m); deeper water materials might be conspecific but were dried out. The other records indicated above require confirmation but they are included because of finding a bluish pigmentation or because specimens were found in deep water.

Figures

FIGURE 1. Flabelligera affinis Sars, 1829. A. Non-type specimens (ZMUB-18636), dorsal view. B. Non-type specimen (MNHN- 184b), anterior end, dorsal view. C. Same, anterior end, ventral view. D. Non-type specimen (MNHN-184a), anterior end, most tunic removed, head exposed (Ca: caruncle, LL: lateral lip, NL: nephridial lobe, PL: palp lobe). E. Non-type specimen (ZMUB- 2253), lateral view, most tunic removed. F. Same, chaetiger 10, notochaetal basal and medial regions (insert: subdistal regions). G. Same, chaetiger 10, neurochaetae (inserts: articulated, median region and crest). Scale bars: A: 1.3 mm, B: 2.3 mm, C: 2 mm, D: 0.5 mm, E: 10 mm, F: 195 µm, G: 120 µm.

FIGURE 2. Flabelligera bicolor (Schmarda, 1861). A. Syntype (BMNH-1908.5.9.33), lateral view. B. Same, anterior end, lateral view. C. Another syntype (BMNH-1908.5.9.33), head, frontal view (BS: branchial scars, Ca: caruncle, LL: lateral lip, VL: ventral lip). D. Same, chaetiger 10, basal and medial notochaetal regions. E. Same, neurohook. F. Same, posterior chaetiger, neurohook (insert: handle articulation). Scale bars: A: 2.2 mm, B: 2.3 mm, C: 1 mm, D: 66 µm, E: 0.30 mm, F: 0.38 mm.

FIGURE 3. Flabelligera bophortica Annenkova-Chlopina, 1924, syntypes (ZIRAS-27043). A. Best syntype, lateral view. B. Same, anterior end, oblique, ventrolateral view. C. Same, head, frontal view (BS: branchial scars, Ca: caruncle, DL: dorsal lip, LL: lateral lip, PS: palp scar, VL: ventral lip). D. Same, neuropodia 4–7, oblique, ventral view showing gonopodial lobes (GL), E. Same, chaetiger 10, notochaetae (inserts: basal, medial and subdistal regions). F. Same, posterior chaetiger, neurohooks (inserts: handle articulation and crest close-up). Scale bars: A: 3.3 mm, B: 1.3 mm, C: 0.5 mm, D: 0.8 mm, E: 320 µm, F: 260 µm.

FIGURE 4. Flabelligera diplochaitus (Otto, 1821). Non-type specimens (MNHN-507). A. Anterior end, dorsal view. B. Same, head, frontal view (BS: branchial scars, DL: dorsal lip, LL: lateral lip, VL: ventral lip). C. Same, close-up showing prostomium (Pr), base of caruncle (Ca), nephridial lobes (NL), and palp scars (PS). D. Another specimen, median chaetiger, cross section. E. Non-type specimens (MNHN-507), chaetiger 9, neurohooks (insert: handle articles). F. Another specimen (MNHN-184), head, frontal view, palps and branchiae removed; arrow indicates parasite. Scale bars: A: 1.2 mm, B: 0.5 mm, C: 0.2 mm, D: 0.7 mm, E: 0.4 mm, F: 0.7 mm.

FIGURE 5. Flabelligera haswelli new name, neotype (AM-8674). A. Complete, bent ventrally, anterior end in dorsal view. B. Same, anterior end in oblique, ventral view. C. Same, anterior end, oblique ventral view. D. Same, anterior end, ventral view. E. Same, chaetiger 14, neurohook. F. Same, chaetiger 22, neurohooks. Scale bars: A, B: 3.7 mm, C: 0.9 mm, D: 1 mm, E: 190 µm, F: 176 µm.

FIGURE 6. Flabelligera infundibularis Johnson, 1901. A. Lectotype (MCZ-2503), ventral view. B. Same, anterior end, dorsal view. C. Same, anterior end, ventral view. D. Paralectotype (LACM-AHF-535), head, frontal view (Ca: caruncle, LL: lateral lip, PS: palp scar, VL: ventral lip). E. Non-type specimen (USNM 186478), head, frontal view (BS: branchial scars, PS: palp scar). F. Lectotype, detached neurohook. G. Same, crest (insert: handle articulated portion). Scale bars: A: 7 mm, B: 2.4 mm, C: 2 mm, D, F: 0.5 mm, E: 1 mm, G: 112 µm.

FIGURE 7. Flabelligera luctator (Stimpson, 1856), topotype specimens (BMNH-1936.10.16.152–7). A. Complete specimens. B. Largest syntype, anterior end, dorsal view. C. Same, head, frontal view (LL: lateral lip, NL: nephridial lobe, PS: palp scar). D. Same, chaetigers 4–7, ventral view (GL: gonopodial lobes). E. Same, chaetiger 5, neurohooks (insert: articulated portion of handle). F. Same, chaetiger 11, neurohook (insert: articulated portion of handle). Scale bars: A: 10 mm, B: 2.3 mm, C: 0.5 mm, D: 0.8 mm, E: 225 µm, F: 160 µm.

FIGURE 8. Flabelligera multipapillata Hartmann-Schröder, 1965, Holotype (ZMH-14911). A. Dorsal view. B. Anterior end, dorsal view; greenish due to methyl green staining. C. Same, chaetiger 12, neurohook (insert: basal and distal regions, enlarged). Scale bars: A: 1.7 mm, B: 0.6 mm, C: 150 µm.

FIGURE 9. Flabelligera nuniezi n. sp. A. Holotype (MNHN/1530), dorsal view. B. Same, ventral view. C. Same, chaetigers 3– 9, left neuropodia, showing gonopodial lobes by arrows. D. Same, chaetiger 10, neurohook. E. Same, chaetiger 22, neurohook. F. Non-type specimen (ZMUC unnumb.), median neurohook (insert: close up of handle anchylosed region). Scale bars: A: 1.3 mm, B: 1.1 mm, C: 0.2 mm, D: 90 µm, E: 100 µm, F: 250 µm.

FIGURE 10. Flabelligera orensanzi n. sp. A. Holotype (MACN-In 39270), dorsal view. B. Same, anterior end, ventral view. C. Paratype (CENPAT), head, frontal view, palps and branchiae removed, prostomium slightly eroded (BS: branchial scars, LL: lateral lip, PS: palp scar). D. Paratype (ECOSUR), chaetiger 9, neurohook (insert: articulated region of handle). E. Non-type specimen (MNHN-884), head, frontal view, two copepod parasites indicated by arrows (Ca: caruncle, BS: branchial scar, VL: ventral lip). Scale bars: A: 0.8 mm, B: 1 mm, C: 0.5 mm, D: 225 µm, E: 0.25 mm.

FIGURE 11. Flabelligera pergamentacea Ehlers, 1913. A. Non-type specimen (ZIRAS-16343), lateral view. B. Same, anterior end, dorsal view. C. Large syntype (ZMB-6774), broken into two pieces, dried out. D. Non-type specimen (ZMH-8592), dried out. E. Non-type specimen (ZIRAS-16343), agglutinated sediment particles on tunic surface. F. Same, chaetiger 10, neurohook (inserts: crest and handle articulated region). Scale bars: A: 2.5 mm, B: 0.5 mm, C: 1.3 mm, D: 1.5 mm, E: 35 µm, F: 50 µm.

FIGURE 12. Flabelligera picta Ehlers, 1913. A. Non-type specimen (ZMH-24295), dorsal view. B. Same, anterior end, dorsal view. C. Same, anterior end, ventral view. D. Same, median chaetiger, notochaetae (inserts: basal and subdistal chaetal regions). E. Same, chaetiger 5, neurohooks (inserts: articulated regions and crests). F. Paratype (ZMH-8591), lateral view. Scale bars: A: 3 mm, B: 0.8 mm, C: 0.7 mm, D: 250 µm, E: 260 µm, F: 1 mm.

FIGURE 19. Flabegraviera profunda n. sp. A. Holotype (USNM-26611), dorsal view. B. Same, anterior end, ventral view. C. Paratype (USNM-unnumb.), head, frontal view, palps and branchiae removed (BS: branchial scars, DL: dorsal lip, LL: lateral lip, PS: palp scar). D. Holotype, posterior chaetiger. E. Same, neurochaetae (insert: neurochaetal tips). F. Smaller paratype, median chaetiger, neurohooks showing poorly developed crest bending sector. Scale bars: A:5.8 mm, B: 1.2 mm, C: 0.6 mm, D: 2 mm, E: 0.4 mm, F: 75 µm.