Perkinsiana anodina Capa, 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 : 147-148

Perkinsiana anodina Capa, 2007

( Fig. 20 G–J)

Perkinsiana anodina Capa, 2007: 549 –551, figs 4J, K, 6, 7A–G.

Material examined. Queensland, Lizard Island: AM W.41049 (3), south of Mermaid Cove, 14°38′53′′S, 145°27′E, coral rubble, 1 Sep 2010; AM W.41051 (2), AM W.41057, MacGillivray Reef, 14°39′23′′S, 145°29′31′′E, coral rubble, 22 m, 29 Aug 2010; AM W.41056 (7), south of Mermaid Cove, 14°38′53′′S, 145°27′E, coral rubble, 14.5 m, 1 Sep 2010; AM W.47332, MI QLD 2359; AM W.43940, MI QLD 2359; AM W.44364, MI QLD 2354 (8).

Description of material examined. All specimens studied incomplete, missing posterior ends; up to 6.0 mm long and 0.8 mm wide, with up to 22 thoracic and numerous abdominal chaetigers. Specimens not studied alive. Preserved specimens have cream coloured body and crown, with no pigmentation; only peristomial eyes pigmented in red ( Fig. 20 G–H, J). Specimens stained with methyl blue show conspicuous ventral shields both in thoracic and abdominal chaetigers ( Fig. 20 I). Radiolar crown with semicircular basal lobes, radioles increasing in length dorsally. Dorsal and ventral basal flanges absent. Basal membrane reduced. Radioles with smooth margin, flanges absent. Four rows of vacuolated cells supporting the radioles basally. Radiolar eyes absent. Dorsal lips with medium-length dorsal radiolar appendages; one pair of dorsal pinnular appendages, similar in length and shape to radiolar appendages. Ventral lips rectangular and prominent, parallel lamellae present, large ventral sacs inside the crown ( Fig. 20 J). Posterior peristomial ring collar with dorsal margins separated by a wide gap; dorsolateral collar margins smooth, without notches, enlarged ventrally into two large ventral lappets separated by a midventral incision ( Fig. 20 G–J). Glandular ridge absent on anterior chaetigers. Thoracic ventral shields separated from uncinial tori by wide gap ( Fig. 20 I–J). First ventral shield with straight anterior margin. Interramal eyespots absent. Collar chaetae elongate narrowly-hooded arranged in two oblique rows. Following thoracic chaetigers with slightly elevated notopodia with superior narrowly-hooded chaetae and inferior paleate chaetae. Thoracic neuropodial tori with avicular uncini with many rows of small teeth occupying half the length of main fang, with reduced breast and long handle. Companion chaetae with an almost symmetrical teardrop-shaped hood with fibrous appearance on proximal half. Abdominal chaetigers with reduced neuropodia, with broadly-hooded chaetae arranged in transverse rows. Abdominal uncini with about 15 rows of small teeth covering 2/3 of length of main fang, well developed breast and medium-length handle. Posterior chaetigers and pygidium missing in all specimens. Tube thin, mucous with some embedded fine sand.

Remarks. Perkinsiana anodina is distinguished from other congeners by a unique combination of characters: dorsal radiolar and pinnular appendages approximately the length of two thoracic chaetigers, thoracic tori and ventral shields separated by a wide gap, first chaetiger similar in length to the remaining thoracic segments, oblique collar with large and subtriangular ventral lappets, and thoracic uncini with handle twice the length of the distance between breast and main fang, with long neck and small breast (Capa 2007). This species can be differentiated from the other species of Perkinsiana present in Australian waters, P. longa Capa, 2007 , as P. anodina lacks an elongate first chaetiger, long dorsal radiolar appendages and the pigmented peristomium characteristic of P. longa (Capa 2007) . This species is not common and only eight specimens are known so far from Australia, so these records double the number of collected specimens. First record for Queensland.

Habitat. Dead coral, sand nearby coral reefs and fouling fauna in artificial substrates, 5–10 m depth.

Type locality. Angel Island, Dampier Archipelago, Western Australia.

Distribution. Australia (Western Australia, Northern Territory, Queensland).

Figures

FIGURE 20. A – C. Parasabella aberrans. A – B. Live specimens; A. Anterior end, ventral view; B. Same, dorsal view, showing the fleshy swelling with a transverse ridge on first two chaetigers (arrow); C. Preserved specimens, showing a detail of the dorsal swelling, divided in two by a longitudinal incision; D – F. Parasabella sp. cf. P. japonica live specimens; D. Anterior end, side view; E. Radiolar crown, side view; F. Anterior chaetigers with detached radiolar crown; conspicuous ventral shields separated from neuropodial tori; G – J. Perkinsiana anodina, preserved specimens; G. Anterior end, lateral view. H. Same, dorsal view, showing collar margins separated dorsally; I. Specimen stained with methyl blue, anterior chaetigers, with detached crown, showing the length of thorax (arrow), and the stained ventral shields separated from neuropodial tori; J. Anterior chaetigers showing collar ventral lappets and well developed ventral sacs.