Flabehlersia persimilis ( Annenkova-Chlopina, 1924 ) Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, Revision of Flabelligera Sars, 1829 (Polychaeta: Flabelligeridae) 3203, Zootaxa 3203 (1), pp. 1-64 : 48-50

Flabehlersia persimilis ( Annenkova-Chlopina, 1924) n. comb.

Figure 21

Flabelligera persimilis Annenkova-Chlopina 1924:127 ; Uschakov 1950:206. Type material. Northwestern Pacific Ocean. Holotype (ZIRAS-27067), near the mouth of Busse Bay, Southern Sakhalin Island, trawl, 2–3 m, sand, 24 Aug. 1901, P.Y. Schmidt, coll.

Description. Holotype complete, partly dehydrated, several parapodia previously removed ( Fig. 21A ). Body prismatic, roughly triangular in cross-section, flat ventrally, tapering towards both ends; 23 mm long, 3.5 mm wide, cephalic cage 2.5 mm long, about 33 chaetigers. Tunic thick, opaque, golden, papillated, covering chaetae almost completely.

Cephalic hood not exposed; not dissected to avoid further damage. Prostomium and caruncle not seen. Palps shorter than branchiae, about twice as wide as branchiae; palp bases, lips, and nephridial lobes not seen. Branchiae all cirriform, sessile on branchial plate, separated into two lateral groups; branchial number unknown (60 in the original description, probably less), about 1/3 longer than palps.

Cephalic cage damaged, forming a long closed cone ( Fig. 21A–C ); chaetae as long as 1/9 body length or slightly shorter than body width. Chaetiger 1 involved in cephalic cage, about 24 noto- and 20 neurochaetae. Anterior dorsal margin of chaetiger 1 smooth (ventral margin projected anteriorly). Chaetigers 1–3 progressively longer. Chaetal transition from cephalic cage to body chaetae abrupt; chaetiger 2 with multiarticulated neurohooks (broken, bases left). Ventral gonopodial lobes in chaetigers 5–6, low, transparent, rounded.

Parapodia well developed ( Fig. 21D ); notopodia and neuropodia ventrolateral. Notopodia short, foliose, rounded lobes with long papillae, projected over chaetae. Neuropodia short, conical lobes with long papillae, projected over chaetae. Noto- and neuropodia close to each other.

Median notochaetae arranged in short transverse rows. Notochaetae of median chaetigers multiarticulated capillaries, 1/3–1/4 as long as body width, 8–9 per bundle, with articles very short, mostly weakly developed in basal and medial regions, distally short articles ( Fig. 21E ). Neurochaetae multiarticulated capillaries in chaetiger 1; multiarticulated neurohooks from chaetiger 2, mostly single. Handle articulation medially placed, articles regular, decreasing in size distally; 4–5 articles: one long, others medium sized. Other articles anchylosed, small, continued to bending region ( Fig. 21D , insert). Crest slightly wider than handle, dark brown along body; width:length ratio 1:5.

Posterior end tapering, conical, completely covered by tunic; pygidium with anus terminal, without anal cirri.

Remarks. Flabehlersia persimilis ( Annenkova-Chlopina, 1924) n. comb. differs from F. induta especially in the relative transparency and color of the tunic. In F. persimilis the tunic is opaque, golden, or yellow-reddish, whereas in F. induta it is more transparent and thinner. Further, the relative sizes of the notochaetal articles differ as well: in F. persimilis , the articles are small throughout the chaeta, becoming barely medium-sized near the tip, whereas in F. induta , articles are small basally, becoming long medially and distally.

Distribution. Only recorded in the type locality in the Tartar Sea, Okhotsk Sea.

Figures

FIGURE 21. Flabehlersia persimilis (Annenkova-Chlopina, 1924) n. comb. A. Holotype (ZIRAS-27067), body twisted, oblique dorsal view. B. Same, anterior end, lateral view. C. Same, anterior end, ventral view. D. Same, chaetiger 10, right parapodium, anterior view (inserts: neurohook before and after removal of other chaetal fragments). E. Same, basal, medial and distal notochaetal regions. Scale bars: A: 1.4 mm, B: 1 mm, C: 0.5 mm, D: 0.28 mm (insert: 0.14 mm), E: 50 µm.