Scolelepis hutchingsae Dauer, 1985

Williams, Jason D., 2007, New records and description of four new species of spionids (Annelida: Polychaeta: Spionidae) from the Philippines: the genera Dispio, Malacoceros, Polydora, and Scolelepis, with notes on palp ciliation patterns of the genus Scolelepis, Zootaxa 1459, pp. 1-35 : 17-21

Scolelepis hutchingsae Dauer, 1985

( Figs. 11–13)

Scolelepis (Scolelepis) hutchingsae Dauer, 1985: 678 -681, Fig. 1.

Material examined. Diniwid Beach, Boracay, 11°60´N, 121°54´E, sandy beach, 13 Apr 1999 (four complete specimens, four anterior ends (two with regenerating posterior ends), three posterior ends in alcohol, USNM 1096811).— Philippines, Boracay, White Beach, 11°59´N, 121°55´E, sandy beach, 14 Apr 1999 (three complete specimens, three anterior ends, four posterior ends in alcohol, ZRC 2006.0224; one complete specimen on two SEM stubs, one pair of palps on SEM stub, USNM 1096812).

Description. Largest specimen of 73 setigers, 16.3-mm long, 0.8-mm wide at setiger 16. Body widest anteriorly, gradually tapering to posterior end; body nearly rectangular in cross section. Color in alcohol opaque white, no pigmentation present.

Prostomium conical, extending anteriorly to sharp point, posteriorly continuing as short, pointed caruncle, to middle of setiger 1; peristomial wings surrounding base of palps ( Figs. 11 A–B, 12A–E). Eyes and occipital tentacle absent. Palps extending to about setiger 15, with two distinctly separated transverse rows of cilia along ventral surfaces, with long and short rows in approximately 2:1 ratio, longer rows of cilia approximately 35-µm long, shorter rows approximately 10-µm long and elevated on 5–10 µm lobes (oriented medially) Species Author Occipital Neuropodial Neuropodial Notopodial Notosetae Branchial fusion Notes tentacle hooks, hooks, # of hooks setiger 1

begin on setiger teeth

alisonae sp. n. present study Absent 29-32 2 Present Present Partially fused (tips free) notopodial postsetal lamellae with up to 9 lobes by setiger 5; neuropodial postsetal lamellae with up to 3 lobes by setiger 5

anakenae Rozbaczylo & Castilla 1988 Absent 35-37 2 Absent Present Partially fused (tips free) Not cited in Hutchings et al.

1998

dicha Hutchings, Frouin & Hily, 1998 Absent 26-32 2 Absent Absent Fused basally

laciniata Eibye-Jacobsen, 1997 Absent 24-26 2-3 Absent Absent Partially fused (tips free) Not cited in Hutchings et al.

1998; notopodial postsetal lamellae with up to 5 lobes by setiger 18

magnicornuta sp. n. present study Present 25-30 2 Present Present Partially fused (tips free

anteriorly, at base posteriorly)

magnus Ozolin'sh, 1990 Present 34 2 Present Present Completely fused (anterior)

marionis Branch, 1998 Absent 42 2 Absent Present Partially fused (tips free)

villosivaina sp. n. present study Absent 25-29 1-2 Present Present Partially fused (tips free)

vazaha Eibye-Jacobsen & Soares, 2000 Absent 25-31 3 Present Present Partially fused (at base) large notopodial spines on

setiger 4

( Figs. 12 G–H, 18D); rows of mucus secreting cells (represented by tubular necks) present proximal to transverse ciliary rows, median ciliated groove absent; base of palps with ciliary patches ( Fig. 12 E–F). Nuchal cilia in U-shaped pattern on both sides of caruncle, posterior to the base of palps ( Fig. 12 E).

Setiger 1 well developed with rounded notopodial and neuropodial postsetal lamellae, notosetae and neurosetae present. Postsetal neuropodial lamellae of setigers 1–18 rounded, becoming broadest by setiger 10 ( Figs. 12 A–D; 13A–B), by setiger 20 lamellae forming low, broad lobe ( Figs. 11 C, 13B), lamellae of posterior setigers broadly triangular on dorsal end, rounded on ventral end with neurosetae ( Fig. 13 D–E). Lateral organs present from setiger 1 between notopodial and neuropodial postsetal lamellae continuing to posterior setigers ( Fig. 13 A, B).

A B C D E F G H I F-I Notosetae of setiger 1 and subsequent setigers arranged in two vertical rows of limbate capillaries ( Fig. 11 I), dorsalmost notosetae of these rows longer than ventral ones; 1–3 notopodial hooded hooks from setiger 18–20, with up to four hooks per fascicle in posterior setigers; notopodial hooded hooks bidentate with acute main fang and single accessory tooth ( Fig. 11 H). Neurosetae of setiger 1 and subsequent setigers in two vertical rows of limbate capillaries ( Fig. 11 G), 1–3 neuropodial hooded hooks from setiger 17–20, typically with 5–8 hooks in middle to posterior setigers; neuropodial hooded hooks bidentate with acute main fang and single accessory tooth, neuropodial hooded hooks with longer shafts than notopodial hooded hooks ( Figs. 11 F, 13C).

Branchiae from setiger 2, fused to postsetal notopodial lamellae for about half of branchial length in anterior setigers, fusion reduced to about one-third of branchial length in posterior setigers; with band of cilia along inner edge of each branchia, joined to corresponding branchiae on opposite side by two dorsal ciliary bands, anterior band broader than posterior band ( Fig. 12 B).

Pygidium broadly rounded, with short conical papillae surrounding dorsal anal opening ( Figs. 11 D–E, 13D–E).

Remarks. The Philippine specimens agree with the original description of Scolelepis hutchingsae from Lizard Island, Australia by Dauer (1985) including the palp morphology ( Dauer 1987, 1994). As indicated previously for S. alisonae sp. n., S. hutchingsae belongs to a group of five species that possess notosetae on setiger 1, notopodial hooded hooks, bidentate neuropodial hooded hooks, and lack an occipital tentacle. Scolelepis hutchingsae is unique in the genus in possessing notopodial hooded hooks that begin in the same setiger or one setiger posterior to the beginning of the neuropodial hooded hooks. In addition, S. hutchingsae has patches of cilia at the base of the palps on the dorsal side near the caruncle and nuchal organ, although these patches of cilia were not noted in specimens from Australia ( Dauer 1985).

Two of the specimens of S. hutchingsae exhibited posterior ends that were regenerating. Two incomplete specimens (posterior end fragments) collected in April had eggs within the body. One specimen had five bivalve larvae in the digestive tract, each approximately 480-µm long.

Distribution. Sandy beach in Boracay of the Aklan province in the Philippines; shallow subtidal (<5 m); Australia (Lizard Island, GBR).

Figures

FIGURE 12. Scolelepis hutchingsae A – G, voucher specimens (USNM 1096812) SEM micrographs. A, anterior end, lateral view (palp missing on right side); B, anterior end, dorsal view; C, anterior end, oblique en-face view; D, anterior end, lateral view; E, caruncle and nuchal organ (base of palp at top, arrowhead indicates patches of cilia on palp base shown in F); F, base of palp with patches of cilia; G, lateral view of palp; H, middle region of palp, oblique frontal view (arrowheads show two short ciliary rows on elevated lobes). Scale bars: A – B, D = 250 µm; C = 125 µm; E = 50 µm; F = 25 µm; G = 100 µm; H = 20 µm.

FIGURE 13. Scolelepis hutchingsae A – E, voucher specimens (USNM 1096812) SEM micrographs. A, setigers 2 – 4 (left to right), lateral view (arrowhead indicates lateral organ); B, setigers 13 – 21 (right to left), lateral view (arrowhead indicates lateral organ); C, setiger 20 neuropodial hooded hooks; D, posterior setigers and pygidium, dorsal view; E, posterior setigers and pygidium, lateral view. Scale bars: A, D = 100 µm; B = 250 µm; C = 25 µm; E = 250 µm.