Flabelligera diplochaitus ( Otto, 1821 )

Salazar-Vallejo, Sergio I., 2012, Revision of Flabelligera Sars, 1829 (Polychaeta: Flabelligeridae) 3203, Zootaxa 3203 (1), pp. 1-64 : 16-18

Flabelligera diplochaitus ( Otto, 1821)

Figure 4

Siphostoma diplochaitus Otto 1820:12–16 , Pl. 2, Figs. A–R (diss.); de Quatrefages 1849:287–288; Mueller 1852:7–14, Pl. 2,

Figs. 1–18 . Siphostoma diplochaites: de Blainville 1828:494 , Fig. in Atlas. Siphostoma diplochaitos: Cuvier 1830:196 ; Costa 1841:272–276, Pl. 12, Figs. 1a–h (Redescr., clarified dorsal vessel and other anatomical features); Oug et al. 2011:5, Figs. a, b. Siphostoma diplochaitum: de Quatrefages 1866:478 . Siphonostoma diplochaitos: Otto 1821:628–633 , Pl. 51; delle Chiaje 1841:74–75, 80, 96, Pl. 109, Textfig. 8–10; Claparède

1869:109–113, Pl. 25, Figs. 3A–E (Anatom. Redescr.); Jourdan 1887:1–43, Pls. 1–4 (Anat.). Siphonostoma diplochaetus: Hartwich 1993:95 . Flabelligera diplochaitus: Günther 1912:10–11 , n. comb. (syn.), 16–95 (monogr.); Fauvel 1927:114–115, Figs. 40g –o; Rioja-

LoBianco 1931:90–92, Pl. 25, Pl. 26, Figs. 1–12 .

Type material. Mediterranean Sea. Five fragments ( ZMB-108 ), not available because of their preservation state; without collection data, probably belonging to the original material .

Additional material. Mediterranean Sea. One specimen ( MNHN-183 ), Naples, 1895, no further data. Several specimens ( MNHN-184 ), four complete, Gulf of Naples , Aug. 1920 , several with copepod parasites ( Flabellicola neapolitana Gravier ) (complete ones measured). One specimen ( MNHN-457 ), Naples; no further data. Three specimens ( MNHN-507 ), one complete, Naples , Aug. 1920 , with parasitic copepod scars (complete one measured). Five specimens ( MNHN-507 b), four complete, Marseille Rhone channel, no further data. Two specimens ( USNM 5124 ), purchased from the Zoological Station , Naples , Italy, 1893 (used for description). Northwestern France. Three specimens ( MNHN-507 c), nocturnal pelagic collecting, Cherbourg, le Môle, east side, outside ‘des presers’, 25 Jun. 1928 .

Description. Non-type specimens (USNM 5124) complete; body cylindrical, tapering posteriorly; 93–96 mm long, 8 mm wide, cephalic cage 5 mm long, 46–50 chaetigers. Tunic thick, transparent, with many fine clavate papillae ( Fig. 4A ), with very few foreign particles.

Cephalic hood not exposed. Prostomium low, with four oval eyes. Caruncle prominent, extending beyond branchial plate ( Fig. 4B ). Palps massive; palp bases prominent. Lateral lips well developed; dorsal lip prominent, ventral lip reduced.

Branchiae divided into two lateral groups of about 100 filaments per side, filaments as long as palps but palps heavily contracted. Nephridial lobes paired, vesicular, placed above the prostomial level, nephridial tubes eroded ( Fig. 4B, C ).

Cephalic cage chaetae slightly more than half as long as body width. Chaetiger 1 involved in the cephalic cage with about 40 multiarticulated capillaries per ramus. Anterior dorsal margin of chaetiger 1 entire, smooth. Anterior chaetigers without long parapodial papillae. Chaetal transition from cephalic cage to body chaetae abrupt; neurochaetae in chaetiger 2 multiarticulated hooks. Gonopodial lobes not observed.

Parapodia low, narrow, short cones; chaetiger 1 with parapodia foliose, wide. Notopodia lateral; median neuropodia ventrolateral ( Fig. 4D ), low, narrow, short cones. Noto- and neuropodia widely separated.

Median notochaetae arranged in short transverse rows; all notochaetae multiarticulated capillaries, about as long as half body width, about eight per ramus, articles size irregular in different notochaetae. Neurochaetae multiarticulated hooks from chaetiger 2, up to five per ramus (usually three). Handle multiarticulated, slightly expanded distally, crest entire. Handle articulation medially placed, articles roughly similar; 5–6 articles, mostly mediumsized. Other articles anchylosed, small, continuing almost to bending region ( Fig. 4E ). Crest about as wide as handle, yellowish to dark yellowish; width:length ratio 1:8–9.

Posterior end a short cone; pygidium without anal cirri; anus terminal with few small papillae.

Remarks. Flabelligera diplochaitus ( Otto, 1821) is separated from the rest of species with transparent tunics by having 3–5 neurohooks with very long crests (width:length ratio 1:8–9) per neuropodium.

The original combination had a misconstructed adjective. Thus, it might have to be modified to a correct spelling as F. diplochaeta , but the new name, albeit slightly different, might generate confusion which is not advisable, and consequently the name is being kept in its original spelling as Flabelligera diplochaitus .

This might be the best studied flabelligerid polychaete species. After the lengthy original description by Otto (1821), several publications or monographs have been devoted to the morphology and anatomy of this species: Costa (1841), Mueller (1852), Claparède (1869), Jourdan (1887), and Günther (1912). However, these efforts were based mostly on morphology and biology, such that we do not know its reproductive biology or its ecology beyond a series of publications on parasitic copepods by Gravier (1918a, b, 1923a, b, 1924); additional efforts should move in those directions. Copepod parasites ( Flabellicola neapolitana Gravier ), which are noticed by their exposed, globular body ( Fig. 4F ), can be as abundant as five per specimen and are usually placed along the cephalic hood’s inner surface.

Distribution. Widely known in the Mediterranean Sea and northeastern Atlantic Ocean. The records from the Arabian Sea by Monro (1937:304), as well as those made for Western Africa by Fauvel & Rullier (1957:375–376; 1959a:180; 1959b:958), could not be confirmed and the presence of this species in these areas is regarded as questionable.

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 13. Flabelligera salazarae n. sp. A. Holotype (ECOSUR 117), dorsal view. B. Same, anterior end, ventral view. C. Paratype (ECOSUR), head, frontal view, palps and most branchiae removed (BS: branchial scars, Ca: caruncle, LL: lateral lip, NL: nephridial lobe, PS: palp scar, VL: ventral lip). D. Holotype, chaetigers 3–6, left side, ventral view, methyl green stained, arrows point gonopodial lobes. E. Same, chaetiger 24, neurohook (inserts: multiarticulated region and crest). Scale bars: A: 1.5 mm, B: 1 mm, C: 0.2 mm, D: 0.4 mm, E: 230 µm.

FIGURE 14. Flabelligera sordida (de Quatrefages, 1849) reinstated. A. Holotype (MNHN-466), dorsal view. B. Non-type specimen (BMNH-1955.8.22.1/3), anterior end, dorsal view. C. Same, posterior end, dorsal view. D. Non-type specimen (MNHN-184), irregular, lateral view. E. Same, median chaetigers showing globular papillae. F. Same, head, frontal view, methyl green staining. G. Non-type specimen (BMNH-1955.8.22.1/3), chaetiger 4, notopodium (insert: globular papillae from posterior chaetiger). H. Same, chaetiger 12, neurohook (insert: multiarticulated region). Scale bars: A: 1.5 mm, B: 1.1 mm, C: 1.3 mm, D: 3.3 mm, E: 0.4 mm, F: 0.2 mm, G: 0.6 mm, H: 320 µm.

FIGURE 15. Flabelligera vaginifera (Rathke, 1843). A. Non-type specimen (ZMUB-27502), dorsal view. B. Same, some tunic fragments removed, anterior end, dorsal view. C. Non-type specimen (ZMUB-2254), head compressed by cover slip, branchial plate dislodged (BS: branchial scars, LL: lateral lip, PS: palp scar). D. Another specimen (ZMUB-2273), anterior end, ventral view (arrows indicate gonopodial lobes). E. Same, right chaetigers 5–6 (arrows indicate gonopodial lobes). F. Same, chaetiger 9, neurohooks (insert: multiarticulated region). Scale bars: A: 2 mm, B: 2.2 mm, C: 0.3 mm, D: 3 mm, E: 1.2 mm, F: 0.45 mm.

FIGURE 16. Annenkova mastigophora (Annenkova, 1952) n. comb. A. Lectotype (ZIRAS-27061), oblique, lateral view. B. Same, chaetigers 4–7, left neuropodia, asterisks on gonopodial lobes. C. Same, chaetiger 10, basal, medial and distal notochaetal regions. D. Same, chaetigers 7–11, neuropodia. E. Same, falciger with incurved crest tip (insert: complete neurohook). F. Same, falciger with perpendicular crest tip (insert: complete neurohook). G. Same, falciger with broken crest tip. Scale bars: A: 5 m, B: 0.2 mm, C: 40 µm, D: 1 mm, E: 50 µm, F: 57 µm, G: 50 µm.

FIGURE 17. Annenkova mastigophora (Annenkova, 1952) n. comb. A. Non-type specimen (CAS-26832), dorsal view. B. Same, ventral view. C. Same, head, palps and most antennae removed (BS: branchial scars, Ca: caruncle, LL: lateral lip, PS: palp scar). D. Same, chaetiger 2, neurohook (insert: multiarticulated handle region). E. Same, chaetiger 15, neurohooks (inserts: oligoarticulated regions and crests). F. Same, chaetiger 25, right parapodium, posterior view (notice the single articulation). Scale bars: A: 1.2 mm, B: 1.1 mm, C: 0.25 mm, D: 140 µm, E–F: 190 µm.

FIGURE 18. Flabegraviera mundata (Gravier, 1906) n. comb. A. Syntypes (MNHN-561), larger one in lateral view, smaller one in ventral view. B. Non-type specimen (MNHN-A183), cross-section, posterior chaetigers. C. Smaller syntype, anterior end, ventral view (Ov: ova, Pa: palp). D. Non-type specimen (USNM-271533), head, frontal view, palps and branchiae removed (BS: branchial scars, LL: lateral lip, PS: palp scar). E. Smaller syntype, chaetiger 15, distal notochaetal regions (insert: articulated tip). F. Same, chaetiger 4, neurohooks (inserts: multiarticulated regions and bending portion). G. Same, chaetiger 14, neurohooks (insert: distal part of handle and crest). Scale bars: A: 5.2 mm, B: 1 mm, C: 1.3 mm, D: 0.4 mm, E: 110 µm, F: 230 µm, G: 350 µm.