Flabesymbios roberti, Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, Revision of Flabelligera Sars, 1829 (Polychaeta: Flabelligeridae) 3203, Zootaxa 3203 (1), pp. 1-64 : 55-56

Flabesymbios roberti n. sp.

Figure 24

Flabelligera commensalis: Light 1978:682–683 (partim); Spies 1973:466–470, Pl. 1–9 (non Moore); Spies 1975:188–193, Pl. 1, Fig. 1 , Pl. 2, Fig. 2 , Pl. 4, Figs. 9–10 , Pl. 6, Figs. 19–21 , Pl. 7, Fig. 22 (non Moore); Spies 1977:324–345, Pls. 1–6 (non Moore).

Type material. Eastern Pacific Ocean. Holotype ( LACM-AHF- 2548), Fourth of July Cove (33°26'53" N, 118°29'55" W), Santa Catalina Island, California on Centrostephanus coronatus , 11 Mar. 1950, 1 fathom. One paratype ( CAS- 2639), off NW end of San Clemente Island, California, on C. coronatus , 27 Oct. 1975, 9 fathoms, D. Powell, coll. Three paratypes ( LACM-AHF- 2549), collected in Casino Point (33°20'57" N, 118°19'27" W), Avalon, Catalina Island, California, on Centrostephanus sp , 22 Jun. 2000, 25 fathoms, E.D. Erikson coll.

Description. Holotype (LACM-AHF-1935) mature female, broken into two pieces, some body wall portions damaged ( Fig. 24A ); dark brown dorsally and laterally, dark gray ventrally; without dark bands in chaetiger 1. Body fusiform, swollen, not compressed, tapering posteriorly, posterior region regenerating; 46 mm long, 5 mm wide, cephalic cage 1.5 mm long, 58 chaetigers (broken at chaetiger 35, last 12 chaetigers regenerating). Tunic thin, body surface densely and finely papillated, free from sediment ( Fig. 24B, C ). Dorsal and lateral papillae fusiform with long thick peduncle.

No cephalic hood. Head exposed ( Fig. 24D ). Prostomium low cone, four reddish eyes arranged on corners of a square. Caruncle well developed, separating branchial groups, projecting beyond branchial plate, gray along midline, darker distally, lateral ridges pale. Palps thick, tips black; palp bases low, rounded.

Branchiae separated into two lateral groups, each with about 60 filaments, shorter and thinner than palps, branchiae smaller laterally towards the mouth. Nephridial lobes placed laterally on branchial plate, each with single, thick filament, one longer than other, dark gray, as branchiae.

Cephalic cage chaetae about 3/100 body length or half as long as body width, only chaetiger 1 involved in the cephalic cage, covered by long, black, filiform clavate papillae ( Fig. 24B, C ), middorsally and midventrally discontinuous, about 40 noto- and 30 neurochaetae per bundle. Anterior dorsal margin of chaetiger 1 papillated. Anterior chaetigers without especially long papillae. Chaetigers 1–3 decreasing in size posteriorly. Chaetal transition from cephalic cage to body chaetae abrupt; neurohooks present from chaetiger 2. Gonopodial lobes not seen.

Parapodia reduced; notopodia dorsolateral, neuropodia ventrolateral up to about chaetiger 5, then ventrally displaced. Median notopodia separated from each other, over the body corners. Median neuropodia ventral. Notopodia projecting short lobes, about as wide as each segment, with many long, filiform clavate papillae covering chaetae, forming a bushy lobe but without touching next notopodium, except in heavily contracted regions. Neuropodia low conical lobes with smaller, filiform clavate papillae, barely projecting beyond surrounding papillae. Noto- and neuropodia widely separated.

Median notochaetae arranged in short, longitudinal rows, chaetae diverging as in a fan, all multiarticulated capillaries, pale cinnamon, about 1/10 body width, 7–8 per bundle, with long articles ( Fig. 24E ). Neurochaetae multiarticulated capillaries in chaetiger 1; from chaetiger 2 large multiarticulated neurohooks, one per ramus (rarely 2). Handle articulation basally placed, with single long article. Other articles anchylosed, small, continued to bending region ( Fig. 24F ). Crest slightly wider than handle, dark brown along body, with darker distal half; width:length ratio 1:4.

Posterior end slightly tapered, pygidium with anus dorsal, slightly damaged, without anal cirri.

Variation. Paratype (CAS-2639) complete male, distorted by evisceration of gonads and by swelling of the anterior end, but body not compressed; 22 mm long, 1.5 mm wide, cephalic cage 1 mm long, 54 chaetigers. Testes pink orange, pale, irregular lobes, if aligned, may be as long as at least 2/3 body length. Other paratypes (LACM- AHF) in good condition, two complete (13–18 mm long, 2 mm wide, cephalic cage 1 mm long, 49–59 chaetigers) and one anterior fragment (11 mm long, 2 mm wide, cephalic cage 1 mm long, 37 chaetigers); all with body swollen, not compressed though neuropodia displaced midventrally, dorsal and notopodial papillae black, at least in distal bulb; both complete specimens with anus terminal; one with anus open, showing a midventral ridge and 10 subtriangular marginal papillae along internal margin.

Remarks. Flabesymbios roberti n. sp. is closely allied to F. commensalis but they differ in body pigmentation and sea urchin host. Thus, F. roberti n. sp. has a rather homogenous dark pigmentation and lives on Centrostephanus , whereas F. commensalis has a dorsal darker longitudinal band but a pale venter and lives on Strongylocentrotus .

Etymology. This species is named after Robert B. Spies, who made significant contributions to our knowledge on flabelligerids, and who studied this species (as F. commensalis ) with painstaking detail, such that it might be one of the best known flabelligerids in terms of circulatory system, anterior end morphology, ciliary current patterns, and reproductive biology.

Type locality. Santa Catalina Island , California .

Distribution. Only known from off shore islands in Southern California, on Centrostephanus coronatus , in subtidal rocky bottoms.

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 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 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.

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.

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.

FIGURE 22. Flabesymbios commensalis (Moore, 1909) n. comb. A. Holotype (CAS-20706), lateral view (insert: anterior end, dorsal view). B. Paratype (ANSP-2532), head, frontal view, most branchiae removed (Ca: caruncle, BS: branchial scars, NL: nephridial lobes, Pa: palp). C. Same, anterior end, ventral view, gonopodial lobe in chaetiger 5. D. Holotype, median chaetigers, oblique ventral view. E. Paratype, chaetiger 4, notopodium. F. Same, basal and distal notochaetal regions. G. Paratype (CAS-20707), chaetiger 30, neuropodium (insert: neurohook without surrounding structures). Scale bars: A: 3.3 mm, B: 0.3 mm, C: 0.6 mm, D: 0.8 mm, E: 150 µm, F: 45 µm, G: 150 µm.

FIGURE 24. Flabesymbios roberti n. sp. Holotype (LACM-AHF-1935). A. Complete, oblique lateral view. B. Same, anterior end, dorsal view. C. Same, anterior end, ventral view. D. Same, head, frontal view, many branchiae and left palp removed (BS: branchial scars, Ca: caruncle, Pa: palp, PS: palp scar). E. Same, chaetiger 4, right notopodium. F. Same, chaetiger 55, neurohook. Scale bars: A: 3.3 mm, B: 1 mm, C: 1.1 mm, D: 0.5 mm, E: 85 µm, F: 113 µm.