Notaulax

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 : 136-137

Notaulax sp. 1

( Fig. 16A–G )

Material examined. Queensland, Great Barrier Reef: AM W.36475, Linnet Reef, 14°46′50′′S, 145°20′58′′E, coarse coral rubble, 4 m, 23 Feb 2009; AM W.36591, North Direction Island, 14°44′35′′S, 145°30′51′′E, coarse coral rubble, 2–11 m, 17 Feb 2009; AM W.37002, AM W.41374, North Direction Island, 14°44′43′′S, 145°30′18′′E, coarse coral rubble, 8 m, 26 Aug 2010. Lizard Island: AM W.37000, AM W.37001, south of Mermaid Cove, 14°38′53′′S, 145°27′E, coarse coral rubble, 14.5 m, 1 Sep 2010; AM W.37003, AM W.41003, Watsons Bay, 14°39′26′′S, 145°27′03′′E, coarse coral rubble, 4.5 m, 28 Aug 2010; AM W.37020, MacGillivray Reef, 14°39′23′′S, 145°29′31′′E, coarse coral rubble, 22 m, 29 Aug 2010; AM W.37024, reef walk to Loomis Beach, 14°41′02′′S, 145°27′01′′E, sandstone reef, 0.3 m, 7 Sep 2010; AM W.37025, lagoon near east entrance, 14°40′S, 145°28′E, May 2009; AM W.39474 (5), between Bird and South Islands, 14°40′S, 145°28′E, 12 m, dead Porites coral blocks, Jan 1987; AM W.40981, south of Mermaid Cove, 14° 38′53′′S, 145°27′E, coarse coral rubble, 14.5 m, 1 Sep 2010; AM W.41004 (2), reef walk to Loomis Beach, 14°41′02′′S, 145°27′01′′E, 0.3 m, 7 Sep 2010; AM W.41005, Turtle Beach, 14°39′08′′S, 145°27′04′′E, coral rubble, 1 m, 30 Aug 2010; AM W.41401, North Point, 14°38′40′′S, 145°27′17′′E, 20 m, 31 Aug 2010; AM W.43931, MI QLD 2341; AM W.44213, MI QLD 2359 (2); AM W.45161, MI QLD 2446; AM W.45163, MI QLD 2446 (2); AM W.47745, MI QLD 2446.

Description of material examined. Largest specimen 35 mm long, 1.8 mm wide. Eight thoracic and numerous abdominal chaetigers. Radiolar crown with diverse pigmentation pattern among specimens; with three or four darkly pigmented transverse bands on pinnules and lateral margins of radioles, with dark brown predominating in some specimens and others with lighter pigmentation; pigment absent on outer margins of radioles ( Fig. 16A–B, D, F ). Thoracic chaetigers light orange, with pigmentation fading towards abdominal segments ( Fig. 16A, C–D, F–G ). Preserved specimens maintain some colour pattern in the radiolar crown, but pigment along the body fades completely. Radiolar crown with semicircular, thick, stout, elongate branchial lobes fused dorsally near the base of radioles ( Fig. 16A, C–D ). Dorsal and ventral basal flanges along the branchial lobes.

Basal membrane between radioles along 1/3 of their length; radioles without distal radiolar flanges, and short bare tips ( Fig. 16A–C, G ). Four rows of vacuolated cells supporting radioles basally. Around 15–20 ocelli arranged in single or double rows, along radioles for the length of 8–20 pinnular basal insertions ( Fig. 16B, E ). Dorsal lips long, without radiolar appendages. Ventral lips and parallel lamellae present; ventral sacs absent. Posterior peristomial collar complete, slightly higher ventrally ( Fig. 16A, C, G ), with a short ventral notch or incision present in some specimens, dorsally entire or notched. Glandular ridge absent on anterior chaetigers. Thoracic ventral shields in contact with adjacent neuropodial tori, first ventral shield with straight anterior margin ( Fig. 16A, G ). Interramal eyespots absent. Collar chaetae spine-like, arranged in longitudinal, strongly curved rows ( Fig. 16C ). Following thoracic chaetigers with conical notopodia; superior thoracic chaetae broadly-hooded, inferior paleate, without mucro. Thoracic neuropodia with avicular uncini with tiny teeth above the main fang, covering more than half its length, well developed breast and medium-sized handle. Companion chaetae with asymmetrical hood, and loose fibres on most of hood surface. Abdominal neurochaetae on short, slightly elevated neuropodia, with superior paleate chaetae with long mucro and inferior elongate narrowly-hooded chaetae. Neuropodial uncini similar to thoracic but with teeth covering more than three quarters of main fang. Pygidium incipiently bilobed, eyespots absent. Tube thin and transparent without attached sediment.

Remarks. This species is characterised by the presence of radiolar ocelli in groups of around 20 aligned in single row, sometimes in a double row proximally, approximately the length of 8–10 pinnular basal insertions, and an entire posterior peristomial ring collar, slightly convex ventrally and not incised on anterior ventral margin, but with a dorsal incision. It resembles N. rectangulata Levinsen 1884 , described from Denmark, and N. nudicullis ( Krøyer, 1856) from the Virgin Islands, in general number and arrangement of eyes and the shape of collar. Nevertheless, some minor differences have been found indicating the Lizard Island specimens could belong to an undescribed species. Moreover, these two apparently broadly distributed species need revision to clarify species boundaries, probably also including molecular data. A revision of the genus Notaulax in Australia (Capa & Murray in prep.) will try to clarify this and other taxonomic issues in the genus.

Habitat. Coral rubble, 6–16 m depth.

Distribution. Australia (Queensland: Lizard Island).

Figures

FIGURE 16. A – G. Notaulax sp. 1, live specimens. A. Anterior end showing elongate basal radiolar lobes, and anterior margin of collar entire ventrally, and general pigmentation pattern; B. Detail of radioles showing the edge of the basal membrane (white arrows) and the groups of orange ocelli (black arrows); C. Radiolar lobes and anterior thoracic chaetigers, dorsal view, showing arrangement of collar chaetae; D. Anterior end, lateral view; E. Detail of radiolar ocelli; F. Broken specimen, lateral view, showing general pigmentation pattern; G. Detail of anterior end, showing elongate base of radiolar crown, entire ventral collar margin, and ventral shields in contact with neuropodial tori; H – J. Notaulax sp. 2; H. Anterior end showing general colour pattern; I. Detail of radioles showing ocelli arrangement on radioles; J. Base of radiolar crown and anterior thoracic chaetigers. Photographs: A, B, D – F by Alexander Semenov.