Pseudopolydora cf. rosebelae Radashevsky & Migotto, 2009

Radashevsky, Vasily I., 2015, Spionidae (Annelida) from Lizard Island, Great Barrier Reef, Australia: the genera Aonides, Dipolydora, Polydorella, Prionospio, Pseudopolydora, Rhynchospio, and Tripolydora, Zootaxa 4019 (1), pp. 635-694 : 682-684

Pseudopolydora cf. rosebelae Radashevsky & Migotto, 2009

( Figs 31 , 32 )

Pseudopolydora rosebelae Radashevsky & Migotto, 2009: 462 –467, figs 1–6 (adult and larval morphology).

Material examined. Queensland: AM W.45381, MI QLD 2347 (1).

Adult morphology. Single 25-chaetiger anterior fragment about 6 mm long and 1 mm wide ( Fig. 31 ). Irregular black spots present on dorso-lateral sides of chaetigers 1 and 3. White pigment diffused on prostomium and 6–8 anterior chaetigers in life, not visible after fixation. Prostomium anteriorly bifid, extending posteriorly to end of chaetiger 1 as a low caruncle. Nuchal organs ciliary bands on sides of caruncle. Short occipital antenna present on caruncle. Three small black eyes present, comprising two median eyes and right lateral eye. Palps missing.

Chaetiger 1 weakly separated from peristomium, with short capillaries in neuropodia and small postchaetal lamellae in both rami; notochaetae lacking. Chaetigers 2–4 and 6 with slender capillaries in both rami. From chaetiger 7 onwards notochaetae smooth slender capillaries with narrow limbation.

Thin transparent hood, an extension of epithelium, arising from dorsal anterior edge of chaetiger 3. Hood oriented forward and upward at an angle of 30–45° to body surface and forming a prominent pouch above chaetiger 2. Lateral sides of hood curved anteriorly and laterally situated near notopodial postchaetal lamellae of chaetiger 2, but not joined to these.

Chaetiger 5 same in size as chaetigers 4 and 6, with six dorsal superior winged capillaries, two kinds of notopodial spines arranged in a double J-shaped series, and about 20 ventral winged capillaries; notopodial postchaetal lamellae lacking but neuropodial lamellae well developed. Dorsal superior capillaries slightly shorter and fewer than those capillaries on chaetigers 4 and 6. Ventral capillaries same as those on chaetigers 4 and 6. Anterior-row notochaetae enlarged pennon spines with long sharply pointed tip ( Fig. 32 A, C), 12 in a series; posterior-row notochaetae simple falcate spines, 10 in a series ( Fig. 32 A, D).

Hooks in neuropodia from chaetiger 8, up to 14 in a series, not accompanied by capillaries. Hooks bidentate, with upper tooth closely applied to main fang; upper part of shaft with constriction, lower part of shaft bent at right angle ( Fig. 32 B).

Branchiae on chaetigers 7–22, full-sized from chaetigers 8–9, free from notopodial postchaetal lamellae. Nototrochs from chaetiger 7 onwards, each composed of one row of cilia extending onto branchiae.

Narrow transparent oesophagus extending to end of chaetiger 12. Ventral buccal bulb and gizzard-like structure in digestive tract absent.

Main dorsal blood vessel without heart body. Blood transparent, without elements and colored respiratory pigment.

Nephridia from chaetiger 4 onwards.

Remarks. Pseudopolydora rosebelae was originally described from the states of São Paulo and Rio de Janeiro by Radashevsky & Migotto (2009). Since then, the species had not been reported outside of Brazil. Adults are unique among spionids in their pigmentation pattern (intense black and white pigment on dorsal side of head and anterior chaetigers), dorsal pouch over chaetiger 2, and transparent blood without coloured respiratory pigment. The only anterior fragment from Lizard Island has white pigment on the dorsal side of anterior chaetigers and a dorsal pouch over chaetiger 2 similar to that in the Brazilian worms. It also has a similarly shaped prostomium, a caruncle of the same length and heavy spines of chaetiger 5 of a similar morphology as the worms from Brazil. It slightly differs however in having less intense black pigmentation on anterior chaetigers. It is preliminary identifed as P. cf. rosebelae pending confirmation with a molecular analysis.

Habitat. In this study, a single individual of P. cf. rosebelae was found in coral sand at 10 m depth. Distribution. Brazil;? Australia.

Figures

FIGURE 31. Pseudopolydora cf. rosebelae. A, B—AM W. 45381. A. Anterior end, right lateral view; B. Same, left lateral view. Scale bars: A, B— 1 mm. Photo: A, B—Alexander Semenov.

FIGURE 32. Pseudopolydora cf. rosebelae. A – D—AM W. 45381. A. Notopodial spines of chaetiger 5. B. Bidentate hooded hook from neuropodium of chaetiger 8; C, D. Notopodial spines of chaetiger 5; C. Anterior-row pennon spine with long sharply pointed tip; D. Posterior-row simple falcate spine. Abbreviations: an—anterior-row notopodial spines, po—posterior-row notopodial spines. Scale bar: 20 µm.