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 : 139-140

Notaulax sp. 3

( Fig. 17 )

Material examined. Queensland, Lizard Island: AM W.30381, east lagoon near Bird Island, 14°42′S, 145°30′E coral rubble, 10 m, 31 Oct 2005; AM W.31848 (2), between First beach and Osprey Island, 14°42′S, 145°30′E, 2 m, 26 Oct 2005; AM W.41373 (crown), 14°38′51′′S, 145°29′16′′E, 7–12 m, 3 Sep 2010; AM W.197044 (2), lagoon, 14°40′S, 145°27′E, dead coral rock, 12 m, Apr 1978; AM W.43939, MI QLD 2360; AM W.47341, MI QLD 2419.

Description of material examined. Largest complete specimen (in 3 pieces) ~ 31 mm long (crown 9 mm), and 2.8 mm wide. Specimens with 8–26 thoracic and numerous abdominal chaetigers. Live specimens with basal lobes of radiolar crown with one dark spot on each side. Radioles with several irregular thin dark bands and paired black spots distally on each radiole ( Fig. 17 A–B). Thorax darkly pigmented and with a white patch on collar midventrally ( Fig. 17 C). The number of pigmented segments (1–7) varies among specimens. Abdomen white except for a midventral brownish line more evident in some specimens towards the posterior end. Preserved specimens maintain most of crown pigmentation pattern. Radiolar crown with semicircular thick, stout, elongate branchial lobes ( Fig. 17 A). Dorsal and ventral basal flanges along the branchial lobes. Basal membrane between radioles, along 1/3 of their length; radioles with narrow distal radiolar flanges, bare tips of medium length (as long as the length on one pinnule). Four rows of vacuolated cells supporting radiolar basally. Around 20 radiolar ocelli in teardrop-shaped groups on lateral margins of radioles, above the basal membrane, for the length of 5–6 pinnular basal insertions ( Fig. 17 B). Radioles supported by four rows of vacuolated cells at the base. Dorsal lips long. Posterior peristomial collar with dorsal margins with a dorsal notch and a ventral lobe separated by a short midventral incision. Thoracic ventral shields in contact with neuropodial tori ( Fig. 17 C). Collar chaetae spine-like, arranged in straight oblique rows, slightly curved in some specimens. Following thoracic chaetigers with conical notopodia, with superior broadly-hooded chaetae and inferior paleate chaetae with inconspicuous mucro. Thoracic neuropodia with uncini with numerous tiny teeth above the main fang, covering more than half its length, well developed breast and medium-sized handle. Companion chaetae with dentate appearance on proximal half of hood, distally asymmetrical. Abdominal notopodia with superior paleate and inferior elongate narrowly-hooded chaetae. Neuropodial uncini similar to thoracic but with teeth covering more than three quarters of main fang. Pygidium rounded with lateral patches of red eyespots. Tube not studied.

Remarks. This species is characterised by the presence of teardrop-shaped groups of radiolar ocelli, with about 20 in each group, occupying the length of 5–6 pinnular bases, a collar slightly incised ventrally and a particular colour pigmentation in the crown, of thin brown transverse bands proximally and paired spots distally on the radioles. Other congeners described with a ventrally incised collar and oval groups of ocelli include N. nudicollis ( Krøyer, 1856) , from Virgin Islands, N. alticollis Grube, 1868 , from Red Sea and N. marenzelleri ( Gravier, 1906) , from Red Sea.

Habitat. Dead coral and coral rubble in shallow subtidal water, 2–16 m depth.

Distribution. Australia (Queensland: Lizard Island).

Figures

FIGURE 17. Notaulax sp. 3, live specimens. A. Radiolar crown showing general colour pattern; B. Detail of radiolar pigmentation, basal membrane edges (white arrows) and radiolar ocelli arranged in compact groups (black arrows); C. Thoracic chaetigers, lateral view, showing collar morphology and chaetal arrangement.