Leodamas dendrocirris ( Day, 1977 )

Zhadan, Anna, 2020, Review of Orbiniidae (Annelida, Sedentaria) from Australia, Zootaxa 4860 (4), pp. 451-502 : 474-475

Leodamas dendrocirris ( Day, 1977)

Figure 12

Scoloplos (Leodamas) dendrocirris Day, 1977: 230–231 , fig. 2f–i.

Material examined. New South Wales: 1.6 km east of Malabar , 33°58’15”S, 151°17’ E; 04.12.1973, coll. Australian Museum Shelf Benthic Survey, depth 66 m, AM W.7344, Holotype; same, place, AM W.6481, Paratype, 1 specimen ; same locality, 30.01.1974, AM W.6477, 1 specimen ; east of North Head, Port Jackson , 33°48’46”S, 151°20’59”E, 24.07.1989, coll. Fisheries Research Institute ( NSW), depth 60 m, sand, AM W.24303, 1 specimen . Queensland: Lucinda, Sugar Loading Jetty Outer , 18°32’ S, 146°20’ E, 01.06.1999, coll. CRC Marine Research, benthic grab, AM W.30586, 1 specimen .

Type locality. East of Malabar , New South Wales .

Description. All specimens studied posteriorly incomplete. Large worms, thoracic width 1.4–4.5 mm. Thorax flattened and widened, abdomen cylindrical ( Fig. 12A ). Prostomium short and wide, bluntly conical ( Fig. 12A, B ). Thoracic chaetigers numbering 14–18. Branchiae from chaetiger 5, triangular in anterior abdomen, then rapidly becoming elongate with tapering tips; in abdomen longer than notopodial lobes ( Fig. 12A, B, D, F, H ). Thoracic notopodial postchaetal lobes branched, with 2–5 digitiform lobes ( Fig. 12A, C ); in larger specimens beginning from first chaetiger, in smaller from chaetiger 3. Abdominal notopodial lobes branched forming two lobes in anterior abdomen, then becoming uniramous ( Fig. 12D , F–H). Thoracic neuropodial postchaetal lobes mammiform, with a single papilla ( Fig. 12B, C, E ). No subpodal or stomach papillae. Abdominal neuropodial lobes with cirriform outer lobes and reduced inner lobe ( Fig. 12C , F–H). All parapodia with crenulated capillaries; thoracic neuropodia also bearing 3–5 rows of curved uncini, smooth or with fine serration and distal longitudinal groove on convex side; in anterior row uncini thicker, finely serrated and bent, in posterior row slenderer, almost straight ( Fig. 12C, E ). Capillary chaetae located in anterior and posterior rows in thoracic neuropodia, forming superior and inferior tufts ( Fig. 12B, C, E ). Both abdominal notopodia and neuropodia bearing stout aciculae; straight and slightly emergent in notopodia, with curved tips and strongly emergent in neuropodia ( Fig. 12 F–H). Forked chaetae present in abdominal notopodia.

Distribution. Australia, Queensland, New South Wales.

Habitat. Subtidal, sand.

Remarks: Leodamas dendrocirris was described from Australia (New South Wales) and has not been recorded elsewhere since. The present study expands the distribution of L. dendrocirris to Queensland. Leodamas dendrocirris is similar to Leodamas verax Kinberg, 1866 from South America, owing to the branched notopodial lobes and shape of the thoracic neuropodial uncini, but differs owing to a smaller number of thoracic chaetigers (14–18 vs. 22–24 in L. verax ), branched notopodial lobes (2–5 vs. 1–4 branches in L. verax ), and presence of capillary chaetae in the thoracic neuropodia (absent in L. verax ). The presence of acicula in the abdominal notopodia is mentioned in the original description of L. dendrocirris and confirmed in the present study, but erroneously stated as absent by Blake (2017) and Sun et al. (2018). Leodamas tribulosus Ehlers, 1897 and Leodamas perissobranchiatus Blake, 2017 from South America, and Leodamas sinensis Sun et al., 2018 from China are similar to L. dendrocirris in having neuropodial lobes with developed papilla and neuropodial uncini with a distal notch or groove on the convex side. However, they differ from L. dendrocirris in having simple notopodial lobes. Additionally, in L. tribulosus the grooves on the neuropodial uncini are deeper and terminate in bifid tips, and the abdominal notopodial aciculae are absent, while L. perissobranchiatus has branched branchiae.

Figures

FIGURE 12. Leodamas dendrocirris, A, C, D: AM W.7344 (holotype), B: AM W.6581, E–H:AM W.30586.A–D: stereomicroscope, methylene blue staining; E–H: compound microscope.A. General dorsal view; B. Anterior end of the body, dorsal view; C. Thorax-abdomen transition, dorso-lateral view; D. Abdomen, dorsal view; E. Neuropodium of chaetiger 9; F, G. Anterior abdominal parapodia; H. Posterior abdominal parapodium. a, acicula; br, branchia; cc, crenulated capillaries; fc, forked chaeta; ne, neuropodium; no, notopodium; u, uncini.