Terebrasabella hutchingsae Murray & Rouse, 2007

Capa, María & Murray, Anna, 2015, A taxonomic guide to the fanworms (Sabellidae, Annelida) of Lizard Island, Great Barrier Reef, Australia, including new species and new records, Zootaxa 4019 (1), pp. 98-167 : 156-157

Terebrasabella hutchingsae Murray & Rouse, 2007

( Fig. 23 E–G)

Terebrasabella hutchingsae Murray & Rouse, 2007: 53 –56, figs 1–4.

Material examined. Queensland. Holotype: AM W.29451, Outer Yonge Reef, northeast of Lizard Island, 14°36′S, 145°38′E, rock and coral rubble covered with pink coralline algae and encrusting sponges, 21 Jan 1977, 9 m. Paratypes: AM W.29452, AM W.29453, AM W.29454, AM W.29455 (2), all from same locality, date, depth and habitat as holotype; AM W.29456 (17), AM W.29457 (3), AM W.29458 (2), AM W.29459 (2), AM W.29460 (3 on SEM), AM W.29461, AM W.29462 (2), AM W.29463, all from Outer Yonge Reef, Great Barrier Reef, 14°36′S, 145°38′E, rock and coral rubble, 21 Jan 1977, 9– 10 m.

Description of material examined. Specimens up to 4 mm long and 0.5 mm wide with eight thoracic and three abdominal chaetigers. Only preserved specimens studied — all white after preservation. Anterior half of body slender, elongate and posterior abdomen slightly expanded, sac-like, external segmentation indistinct (generic features only shared with Caobangia Giard, 1893 within Sabellidae ). Radiolar lobes semicircular, with two pairs of radioles with up to eight pinnules and filamentous distal ends. Ventral basal flanges present, dorsal basal flanges absent. Basal membrane, radiolar flanges and radiolar eyespots absent. Two rows of vacuolated cells support the radioles near the base. Dorsal lips with short radiolar appendages. Ventral lips, ventral sacs and parallel lamellae absent. Posterior peristomial ring collar vestigial, fused dorsally to faecal groove and with small ( Fig. 23 E), rounded ventral lappets separated by a midventral incision. Glandular ridge on anterior chaetigers absent. Poorly developed ventral shields on chaetigers 1–5, 7–8 and 9–11. Collar chaetae broadly-hooded. Following thoracic notochaetae arranged in transverse rows on inconspicuous notopodia, broadly-hooded. Neuropodial uncini of second chaetiger acicular “palmate” uncini, with different-sized teeth arranged in a semicircle over main fang, underdeveloped breast and long handle ( Fig. 23 F). Neuropodia of chaetigers 3–6 with acicular uncini with two larger teeth surmounted by smaller teeth over the main fang ( Fig. 23 G). Neuropodia of chaetigers of 7–8 with numerous rasp-shaped avicular uncini with five rows of small teeth over the main fang, well developed breast and long handle. Companion chaetae present on chaetiger 3–6, with dentate appearance at proximal half of hood, distally asymmetrical ( Fig. 23 G). Abdominal neurochaetae narrowly-hooded. Abdominal notopodial uncini “palmate”, similar to those in chaetiger 2, but smaller. Pygidium inconspicuous, anus dorsal. Pygidial eyespots absent. Pygidial cirri absent. Tube a mucilaginous sheath, lining burrow inside dead coral.

Remarks. Terebrasabella hutchingsae is the only species in the genus bearing “palmate” uncini, found in neuropodia of chaetiger 2 and abdominal notopodia. The other two species in the genus lack this type of uncini.

Habitat. Rock and coral rubble at 9– 10 m. Not abundant.

Type Locality. Lizard Island.

Distribution. Australia (Queensland: Outer Yonge Reef, northeast of Lizard Island).

Figures

FIGURE 23. A – D. Terebrasabella fitzhughi, scanning electron micrographs; A. Anterior end, ventral view, showing the ventral margins of collar separated by a narrow gap; B. Same, lateral view; C. Thoracic neuropodial uncini, chaetiger 3, with several rows of teeth above the main fang; D. Neuropodium chaetiger 3, showing the uncini and the companion chaetae with bent hoods, with proximal fibres; E – G. Terebrasabella hutchingsae; E. Anterior chaetigers, lateral view, showing “ palmate ” uncinus from chaetiger 2 (arrow); F. Detail of “ palmate ” uncinus; G. Uncini and companion chaetae, with bent hood and proximal fibers, chaetiger 2.