Flabehlersia induta ( Ehlers, 1897 ) Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, Revision of Flabelligera Sars, 1829 (Polychaeta: Flabelligeridae) 3203, Zootaxa 3203 (1), pp. 1-64 : 46-48

Flabehlersia induta ( Ehlers, 1897) n. comb.

Figure 20

Flabelligera induta Ehlers 1897:105–107 , Pl. 7, Figs. 168–173; Ehlers 1900:14; Ehlers 1901:179; Günther 1912:13–14; Hartman 1953:50; Hartman 1966:37, Pl. 10, Figs. 1–3 (syn.); Hartman 1967:124; Rozbaczylo 1985:158, Hartwich 1993:108.

Type material. Southern tip of America and Antarctica. 23 syntypes (20: ZMH-4875 ; 3: ZMB-6771 ), Tierra del Fuego , Picton Island, Banner Cove, kelp holdfast, 3 fathoms, 26 Dec. 1882, W. Michaelsen, coll.

Additional material. Three specimens ( SMNH-510 ), one complete and two anterior fragments, Eldslands Expedition, Navarino Island , Chile, 10 fathoms, 13 May 1896 . Two damaged specimens ( SMNH-55708 ), Lund University Chile Expedition 1948–49, Stat. M 47 (41°33'45" S, 73°02'05" W), Seno Renolcavi , between Panitao and Punta Puchegui, Paso Maillen, Golfo de Ancud, 22 m, coarse sand with Chaetopterus tubes, small stones with calcareous algae, 25 Jan. 1949 . One specimen ( SMNH-55709 ), Lund University Chile Expedition 1948–49, Stat. M 21 (41°48'50" S, 73°09'40" W), Canal Calbuco, close to Punta Meimem, Golfo de Ancud , 25 m, 15 Dec. 1948 . One very damaged specimen ( SMNH-55710 ), Lund University Chile Expedition 1948–49, Stat. M 115 (53°11' S, 70°55' W), Estrecho de Magallanes, gravel and clay, mixed with mud, covered with boulders, 3 May 1949 . Two small damaged specimens ( SMNH-55711 ), Lund University Chile Expedition 1948–49, Stat. M 55 (41°51'30" S, 73°49'40" W), close to Punta San Antonio, Bahia de Ancud , 28 Feb. 1949 . One specimen ( SMNH-55713 ), damaged mature female, without posterior end, Lund University Chile Expedition 1948–49, Stat. M 106 (41°48'40" S, 73°21'00 W), between Punta Abato and Isla Abato, Golfo de Ancud , 36 m, 5 May 1949 . One specimen ( SMNH- 55714 ), Lund University Chile Expedition 1948–49, Stat. M 18 (41°45'30" S, 73°07'50 W), Estero Huito , N of Punta Ahuecha, Golfo de Ancud, 35 m, 15 Dec. 1948 . One specimen ( SMNH-55715 ), twisted, Lund University Chile Expedition 1948–49, Stat. M 106 (41°52'42" S, 73°50'46" W), between Punta Abato and Isla Abato, Golfo de Ancud , 36 m, 5 May 1949 (anus prolapsed, brownish) . One specimen ( SMNH-55726 ), and an anterior fragment, Swedish South Polar Expedition 1901–03, Stat. 44 (51°33' S, 58°10' W), Port Louis, Greenpatch , near bridge, Falkland Islands, 7 m, mud, gravel and algae, 28 Aug. 1902 . One specimen ( SMNH-55727 ), and fragments, Swedish South Polar Expedition 1901–03, Stat. 52 (51°40' S, 57°44' W), Port William , Falkland Islands, 17 m, sand, 3 Sep. 1902 . Three specimens ( SMNH-55728 ), Swedish South Polar Expedition 1901–03, Stat. 41 (51°33' S, 58°09' W), Port Louis, Berkeley Sound , Falkland Islands, 2–4 m, gravel and mud, 23 Aug. 1902 . Three specimens ( SMNH-55729 ), damaged, Swedish South Polar Expedition 1901–03, Stat. unnumbered, Mouth of West Fjord, Cumberland Bay , South Georgia Islands , Macrocystis holdfasts, 3 May 1902 .

Description. Redescription based on one syntype resembling Ehlers illustrations. Mature female (ZMH-4875); body cylindrical, flat ventrally, markedly tapering towards both ends ( Fig. 20A, B ); 26 mm long, 4 mm wide, cephalic cage 3 mm long, 38 chaetigers. Tunic thick, papillated, especially ventrally; tunic with fine to very fine sediment particles adhered.

Cephalic hood not exposed. Anterior end observed by dissection of an anterior fragment. Prostomium low cone; four large eyes, anterior ones covered by palp bases ( Fig. 20D ). Caruncle well developed, separating branchiae into two lateral groups. Palps thick, corrugated, not exposed from cephalic cage, as long as branchiae; palp bases rounded, elevated. Lateral lips thick, well developed; dorsal lip thinner but prominent. Ventral lip reduced.

Branchiae arranged in concentric rows, each group with about 90 filaments, longest slightly longer than palps, decreasing in size ventrally. Nephridial lobes tiny, conical, placed below branchial plate at level of prostomium.

Cephalic cage forming a long closed cone ( Fig. 20C ); chaetae as long as 1/10 body length or about as long as body width. Chaetiger 1 involved in the cephalic cage, 36 noto- and 24 neurochaetae. Anterior dorsal margin of chaetiger 1 smooth (two specimens with a dark round midventral structure). Chaetigers 1–3 progressively longer. Chaetal transition from cephalic cage to body chaetae abrupt; chaetiger 2 with multiarticulated neurohooks (left chaetiger 2 with a duplicated notopodium, no neuropodium; not seen in any other specimen). Gonopodial lobes (in other specimens) in chaetigers 5 and 6 ( Fig. 20E ).

Parapodia well developed; notopodia and neuropodia ventrolateral ( Fig. 20F ). Notopodia long foliose lobes with long papillae, projected over chaetae ( Fig. 20G ). Neuropodia long conical lobes with long papillae projected over chaetae. Noto- and neuropodia close to each other.

Median notochaetae arranged in short transverse rows, in many specimens collapsed over the body. Notochaetae of median chaetigers multiarticulated capillaries, about 2/3 as long as body width, 6–8 per bundle, with articles difficult to see in basal and medial regions, distally short articles. Neurochaetae multiarticulated capillaries in chaetiger 1; multiarticulated neurohooks from chaetiger 2, mostly single. Handle articulation medially placed, articles regular, roughly of the same length; 4–5 articles, long. Other articles anchylosed, small, continuing to bending region ( Fig. 20H ). Crest about as wide as handle, dark brown along the body, pigmentation extending towards base; width:length ratio 1:6.

Posterior end tapering, conical; pygidium with anus terminal, a rounded muscular lobe, without anal cirri.

Variation. There are 17 complete syntypes (15 BMNH, 2 ZMB), three anterior fragments (2 in BMNH, 1 ZMB), and two posterior fragments (include museum number), A fusiform sponge was also found in ZMH-4875. Syntype averages are 20.5 mm long (range: 10–27 mm), 3.3 mm wide (range: 2–4.5 mm), cephalic cage 3.0 mm long (range: 2.0–3.5 mm), and 32 chaetigers (10–47). The number of chaetigers varies because animals may be regenerating the posterior end and neurohooks are difficult to see under the notochaetal and tunic cover. The body color depends on sexual maturity because females have dark oocytes and males have yellow or pale testes. The testes cannot be confused with the heart sinus, since blood vessels look whitish under the thin dorsal body wall. In fact, the main dorsal vessels bifurcates by chaetiger 10 into two dorsolateral vessels that zigzag through the body. The specimens from the Lund University Chile Expedition are in poor shape in general but they were collected far from the type locality. They have been included in this species with some hesitation; better specimens will clarify this apparently extended distribution .

Remarks. Flabehlersia induta ( Ehlers, 1897) n. comb. is closely allied to F. persimilis ( Annenkova-Chlopina, 1924) n. comb. However, they differ especially in the sediment cover of the tunic: F. induta has a thin transparent one whereas F. persimilis has an opaque, golden, or yellow-reddish tunic.

The Stockholm materials (SMNH-510) have a tag indicating they were part of the type series, but were not included in Ehlers’ list of materials (1897:107). It could be argued, after Art. 73.2.1 ( ICZN 1999), that they are syntypes, but it would be a mistake because they were collected after the original manuscript was sent to press and they could not have been employed to define the species (Elin Sigvaldadottir, Nov. 2011, email), which is a requisite for following the code. The type materials are abundant: besides the Hamburg material, three syntypes were deposited in Berlin ( Hartwich 1993). The original description and illustrations are adequate, and almost all specimens belong to the same species (the exception is the fusiform sponge), so designating a lectotype is not relevant.

Distribution. Originally described from Tierra del Fuego, Falkland, and South Georgia Islands, in 2–6 m depth.

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 20. Flabehlersia induta (Ehlers, 1897) n. comb. A. Syntype (ZMH-4875), lateral view. B. Another syntype (ZMH- 4875), dorsal view. C. Same, anterior end, oblique ventral view. D. Another syntype (SMNH unnumb.), head, frontal view, methyl green stained, palps and most branchiae removed (BS: branchial scars, Ca: caruncle, LL: lateral lip, PS: palp scar). E. Another syntype (ZMH-4875), chaetigers 5–6, arrows point to gonopodial lobes. F. Median chaetiger (anterior fragment ZMH- 4875), methyl green stained, frontal view. G. Another syntype (ZMH-4875), chaetiger 10, right parapodium. H. Same, neurohook of same. Scale bars: A: 3.6 mm, B: 3.2 mm, C: 1.6 mm, D–E: 0.3 mm, F: 1 mm, G: 350 µm, H: 190 µm.