Scyphoproctus pullielloides Hartmann-Schröder, 1965

Figures 33 B–C, 34 A–D, 35 A–F

Scyphoproctus pullielloides Hartmann-Schröder, 1965: 152 –154, figs 79–82.

Material examined. Oahu Island: Mamala Bay, Sand Island outfall, Sta. D3AR3, 21°16ʹ55.7ʺ N, 157°53ʹ48.3ʺ W, 50.9 m, Aug. 2007 (6, BPBM R3629); Sta. C6R1, 21°16ʹ11.5ʺ N, 157°50ʹ31.2ʺ W, 19.2 m, Aug. 2006 (1); Mamala Bay, Barbers Point outfall, Sta. H4R1, 21°16ʹ46.9ʺ N, 158°01ʹ38.1ʺ W, 63.7 m, Mar. 2000 (2); Sta.

HB4R5, 21°16ʹ47.0ʺ N, 158°01ʹ38.0ʺ W, 63.1 m, Mar. 2000 (1, BPBM R3628); Sta. HB4R3, 21°16ʹ46.9ʺ N, 158°01ʹ38.2ʺ W, 63.4 m, Feb. 2006 (8, BPBM R3626); Sta. HB4R5, 21°16ʹ47.0ʺ N, 158°01ʹ38.0ʺ W, 63.1 m, Feb. 2006 (1, BPBM R3627); Sta. HB2R1, 21°17ʹ0 0.5ʺ N, 158°01ʹ21.1ʺ W, 58.8 m, Mar. 2004 (2); Sta. HB2R4, 21°17ʹ0 0.5ʺ N, 158°01ʹ21.2ʺ W, 59.1 m, Mar. 2004 (1); Sta. HZR5, 21°16ʹ53.7ʺ N, 158°01ʹ29.7ʺ W, 62.8 m, Jan. 2009 (1); Sta. HB2R4, 21°17ʹ0 0.5ʺ N, 158°01ʹ21.2ʺ W, 59.1 m, Mar. 2001 (1); Sta. HZR4, 21°16ʹ53.1ʺ N, 158°01ʹ30.3ʺ W, 62.5 m, Mar. 2002 (1); Sta. HB2R3, 21°17ʹ0 0.4ʺ N, 158°01ʹ21.4ʺ W, 59.4 m, Feb. 2006 (2); Sta. HZR4, 21°16ʹ53.1ʺ N, 158°01ʹ30.3ʺ W, 62.5 m, Feb. 2006 (1); Sta. HB2R2, 21°17ʹ0 0.1ʺ N, 158°01ʹ21.3ʺ W, 60.0 m, Mar. 2000 (2); Sta. HB2R3, 21°17ʹ0 0.4ʺ N, 158°01ʹ21.4ʺ W, 59.4 m, Mar. 2001 (2); Waianae outfall, Sta. W2R2, 21°24ʹ46.5ʺ N, 158°11ʹ45.6ʺ W, 27 m, May 2001 (1); Sta. ZWR5, 21°25ʹ25.1ʺ N, 158°11ʹ55.4ʺ W, 34 m, May 2002 (1); Sta. W2R5, 21°24ʹ46.5ʺ N, 158°11ʹ45.6ʺ W, 27 m, Jun. 2011 (2); Sta. W2R1, 21°24ʹ46.5ʺ N, 158°11ʹ45.6ʺ W, 27 m, May 2001 (2); Sta. W1R2, 21°23ʹ32.5ʺ N, 158°11ʹ27.7ʺ W, 31 m, May 2002 (1); Sta. ZWR3, 21°25ʹ25.1ʺ N, 158°11ʹ55.4ʺ W, 34 m, May 2001 (2); Kailua Bay, Mokapu outfall, Sta. AR1, 21°27ʹ45.6ʺ N, 157°42ʹ43.6ʺ W, Mar. 2008 (3); Sta. AR2, 21°27ʹ45.6ʺ N, 157°42ʹ43.6ʺ W, Mar. 2008 (2); Sta. ZR1, 21°27ʹ14.3ʺ N, 157°42ʹ50.6ʺ W, Mar. 2008 (1); Sta. AR3, 21°27ʹ45.6ʺ N, 157°42ʹ43.6ʺ W, Mar. 2008 (1); Sta. ZR2, 21°27ʹ14.3ʺ N, 157°42ʹ50.6ʺ W, Mar. 2008 (2); Sta. AR4, 21°27ʹ45.6ʺ N, 157°42ʹ43.6ʺ W, Mar. 2008 (2); Maunalua Bay, among branches of the invasive green alga Avrainvillea amadelpha, intertidal depths, 21°16ʹ49.4ʺ N, 157°43ʹ48.5ʺ W, coll. W. Magalhães & B. Dugan, Mar. 2010, Sta. S4R1 (7), Sta. A5R3 (4); Sta. A2R3 (3); Sta. A5R1 (1); Sta. A9R1 (1); Sta. S1R2 (1); Maunalua Bay, Kawainui Beach Park near Niu Valley, south shore of Oahu, Hawaii, 21°16ʹ43.3ʺ N, 157°44ʹ41.5ʺ W, coll. S.A. McCarthy & W.A. Estabrooks (reported in Dreyer et al. 2005): Sta. NV Post 5 (5); Sta. NV Post 8 (4); Sta. NV Post 2 (11); Sta. NV Post 6 (6); Sta. NV Post 4 (4); Kaneohe Bay, Environmental Monitoring and Assessment Program (EMAP), State of Hawaii estuaries and bays, Apr.–Oct. 2002, Sta. 17, 21°25ʹ55.2ʺ N, 157°47ʹ16.8ʺ W (3); Sta. 13, 21°28ʹ19.2ʺ N, 157°48ʹ10.8ʺ W (9, BPBM R3630); Mamala Bay, underneath threadfin mariculture cages, Sta. UR1, 21°17ʹ17.7ʺ N, 158°00ʹ26.5ʺ W, 40.2 m, Feb. 2004 (3); Mamala Bay, Aug. 2001, Sta. 7 (1), Sta. 26 (1); Sta. 10 (1).

Description. Complete specimens 4–30 mm long, 0.2–1 mm wide for 47–70 chaetigers. Body elongate, slender, widest on mid-thoracic chaetigers and posterior abdominal segments. Color in alcohol pale yellow.

Prostomium short, rounded anteriorly (Figs 34 A–B, 35A); nuchal organs not observed; eyespots present in a pair of elongate, pigmented ocular areas, situated in two triangular crests, each composed of about 20 brownish pigment spots (Fig. 34 B). Proboscis finely papillated. Peristomium achaetous, 1.5 longer than anterior thoracic segments (Fig. 34 A, 35A).

Thorax with 12 segments, including one achaetous segment (not including peristomium) and 11 chaetigers (Figs 34 A, 35A). Thorax smooth, segments biannulate with deep inter-segmental grooves and bilimbate capillaries only (Figs 34 A, 35A). First chaetiger biramous (Fig. 34 A). Notopodia inserted dorso-laterally, neuropodia laterally. Lateral organs present throughout, between noto- and neuropodia, but closer to notopodia. Genital pores not observed.

Transition between thorax and abdomen marked by change in shape of segments and chaetae (Fig. 34 A); abdominal segments multiannulated with hooded hooks throughout (Fig. 34 A, 35A). Abdominal noto- and neuropodia with well-separated glandular tori pads (Fig. 35 B, C). Anterior notopodia with 24–26 hooded hooks, reducing to 16–18 hooks in far posterior; neuropodia with 9–10 hooks, reduced to 22, 12, and 4, on last three chaetigers of largest specimen. Abdominal hooks similar to thoracics; hoods short, margins broadly scalloped, not extending beyond main fang nor covering hooks superiorly (Fig. 35 E, F). Hooks with multiple teeth, with 4–5 rows of teeth in frontal view; 4–5 in basal row, increasing from 5–7 in middle row to 8–12 small teeth in superior rows (Fig. 35 E, F). Three pre-plaque segments with triangular lateral lobes and notoacicula (Figs 34 C, D, 35C, D); lobes becoming more rounded towards plaque and continued as its lateral membrane (Figs 34 C, D, 35C, D). Notoacicula numbering 8:9:7 on largest specimen and 3:4:2 on smallest (others with 3:6:4; 4:6:5); anterior two pre-plaque notopodia fused.

Branchiae absent. Pygidium with one chaetiger fused with anal plaque (Figs 34 D; 35D). Plaque flat, spines absent or one set of spines present (3–4 spines each side). Anus moderate size (20% of plaque length), not extending to edge of plaque (Figs 34 D, 35C–D). Two short cirri present with a short median membrane (Figs 34 C–D, 35C–D).

Methyl green staining pattern. Prostomium not stained (Fig. 33 B); peristomium and thoracic region uniformly light to medium green; dorsal region of peristomium, achaetous segment 1 and chaetiger 1 all darkly speckled forming a dorsal green cap (Fig. 33 B). In abdominal region, staining forms dorsal and ventral bands (only the region between noto- and neuropodia is not stained) on the posterior half of the first 2–3 chaetigers; thereafter staining is restricted to parapodial tori, being more intense or only speckled on post-chaetal tori (Fig. 33 C). Posterior end acicular hooks are stained green; pygidium with staining only around noto- and neuropodia of the fused segments (Fig. 33 C). Regenerating posterior ends do not stain. Small specimens, possibly juveniles, stain light green throughout with dark speckles on post-chaetal tori.

Distribution. Originally described from Palmyra Atoll, equatorial North Pacific, U.S. territory (Hartmann- Schröder, 1965) and newly recorded further north in Oahu, Hawaii.

Remarks. The specimens from Oahu agree well with the original description by Hartmann- Schröder (1965). Scyphoproctus pullielloides resembles S. somalus Cantone, 1976 and S. steinitzi Day, 1965 by the fusion of only two posterior segments to the pygidium (Paxton et al. 1984). It differs from these two closely related species by the number of pre-plate segments with both lateral triangular lobes and acicular hooks, length of anal cirri and development of its median membrane. S. somalus has nine pre-plate segments with lateral triangular lobes and acicular hooks while S. pullielloides has up to three.