Flabelligera bophortica Annenkova-Chlopina, 1924

Salazar-Vallejo, Sergio I., 2012, Revision of Flabelligera Sars, 1829 (Polychaeta: Flabelligeridae) 3203, Zootaxa 3203 (1), pp. 1-64 : 14-16

Flabelligera bophortica Annenkova-Chlopina, 1924

Figure 3

Flabelligera bophortica Annenkova-Chlopina 1924:127 ; Jirkov & Filippova 2001:361, Figs. 1–4 .

Type material. Northwestern Pacific Ocean. Eight syntypes ( ZIRAS-27043 ), seven with anterior end, Chukchi Sea, R / V Vaigach, Stat. 164 (69°24' N, 179°34' E), 48 m, mud, 13 Jul. 1912, Z.E. Arngold, coll. Seven syntypes ( ZIRAS-27044 ), very damaged anterior ends, off Cape Jakan, Long Strait , Chukchi Sea, R / V Vaigach, Stat. 142 (69°54' N, 176°08' E), 13 m, pebbles, mud and sand, 31 Aug. 1911, Z.E. Arngold, coll .

Description. Best syntype (ZIRAS-27043) with tunic mostly removed, posterior chaetigers without chaetae, medially swollen ( Fig. 3A ). Body cylindrical, yellowish, tapering posteriorly; 39.5 mm long, 3 mm wide, cephalic cage 3 mm long, 44 chaetigers. Tunic transparent, very thin (from original description), severely eroded; body wall areolated, areoles squarish, about as long as wide (other syntypes with a thin layer of fine sediment); papillae long, distally swollen, some mucronate.

Cephalic hood not exposed ( Fig. 3B ). Prostomium low cone, with four large black eyes. Caruncle well developed, extended slightly beyond the branchial plate margin; medial lobe elevated, dorsally pigmented ( Fig. 3C ); lateral lobes flat, pale. Palps slightly longer than branchiae, contracted; palp bases elevated, rounded. Lateral lips well developed, widened; dorsal lip projected anteriorly; ventral lip reduced.

Branchiae separated into two lateral groups, each with a fold (due to contraction, not seen in other syntypes); branchial filaments in 7–8 rows; each group with about 100 filaments, decreasing in size ventrally; longer filaments about 3/4 as long as palps. Nephridial lobes in branchial plate, base wide, conical, nephridial tube tapered, thin.

Cephalic cage chaetae as long as 1/13 body length or as long as body width. Chaetiger 1 involved in cephalic cage; chaetae mostly broken, about 45 noto- and 20 neurochaetae. Anterior dorsal margin of chaetiger 1 papillated. Anterior chaetigers without especially long papillae. Chaetigers 1–3 decreasing in length posteriorly. Chaetal transition from cephalic cage to body chaetae abrupt; multiarticulated neurohooks from chaetiger 2. Gonopodial lobes in chaetigers 5 and 6; projecting, yellowish, rounded ( Fig. 3D ).

Parapodia well developed, lateral; median neuropodia ventrolateral. Notopodia foliose with long papillae ( Fig. 3E ). Neuropodia conical with long papillae. Noto- and neuropodia widely separated.

Median notochaetae arranged in short rows, either longitudinal or transverse to body axis, depending on body contraction; all notochaetae multiarticulated capillaries, at least as long as body width, 12–14 per fascicle, most with medium-sized articles medially, hardly noticeable basally, becoming longer distally; 1–2 smaller notochaetae with long articles. Neurochaetae multiarticulated capillaries in chaetiger 1; single (rarely 2) multiarticulated hooks from chaetiger 2 ( Fig. 3F ). Handle articulation basally placed, articles irregular (Fibonacci); three articles: medium-sized, long, longer. Other articles anchylosed, small, continued to the bending region. Crest slightly wider than handle, yellowish, distally darker; width:length ratio 1:6(–7).

Posterior end tapering to truncate cone; pygidium with anus terminal, pale muscular ring, without anal cirri. Oocytes in some mature females 100–150 µm.

Variation. The syntype series includes some larger anterior fragments, reaching up to 8 mm wide, so the species may be larger than the described syntype. The body shape in all specimens is cylindrical, anteriorly truncate. The tunic is transparent but the external fine sediment layer renders it opaque.

Remarks. Flabelligera bophortica Annenkova-Chlopina, 1924 might be closely allied to the poorly known F. buski ( McIntosh, 1869) , because both have neurohooks with long crests. These two species differ because F. bophortica has mostly single neurohooks per neuropodium and the crests have a width:length ratio of 1:6(7), whereas in F. buski there are usually two neurohooks per neuropodium and the crests have a width:length ratio of 1:9.

Jirkov & Filippova (2001:361, Figs. 1–4 ) used F. bofortica instead of the original name; such replacement is inadequate. Further, they shortened the author’s last name; although most of her papers were published using only Annenkova , in some publications, including the one where this species was described, she used Annenkova- Chlopina so this must be the author’s name for this species. On the other hand, probably due to space limitations, Jirkov & Filippova inverted their Figure 1 , showing neuropodia as the upper section.

Distribution. Russian Arctic Ocean, in 13–48 m, in fine or mixed sediments.

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.