Scoloplos novaehollandiae ( Kinberg, 1866 )

Zhadan, Anna, 2020, Review of Orbiniidae (Annelida, Sedentaria) from Australia, Zootaxa 4860 (4), pp. 451-502 : 460

Scoloplos novaehollandiae ( Kinberg, 1866)

Figure 4

Labotas novaehollandiae Kinberg, 1866: 252 .

Scoloplos novaehollandiae: Augener 1922: 40–41 , fig. 9.

Scoloplos (Scoloplos) novaehollandiae: Day 1977: 227–228 , fig. l (h–i).

Material examined. New South Wales: Neutral Bay, Port Jackson , 33°50’42”S, 151°13’06”E, September 1908, AM G.11238, 1 specimen ; AM W.7339, 1 specimen (previously examined by Day (1977) from same location.

Type locality. Port Jackson , New South Wales .

Description. Large, stout worms, thoracic width 3.8 and 4.8 mm, length more than 70 mm, more than 200 segments ( Fig. 4A ). Thorax flattened, abdomen cylindrical, segments very short ( Fig. 4 A–E). Prostomium short conical with rounded tip ( Fig. 4B ). Thoracic chaetigers numbering 20. Branchiae from chaetiger 7–8; short triangular on anterior thorax, then gradually lengthening; in abdomen becoming digitate, shorter than notopodial postchaetal lobe ( Fig. 4A, B, D, E, G ). Thoracic postchaetal lobes developed from first chaetiger gradually increasing in size, both triangular in shape; neuropodial lobes all single, broader than notopodial; tips of each lobe forming round papillae ( Fig. 4C ). No subpodal and stomach papillae. Abdominal notopodial lobes long and wide, foliaceous; abdominal neuropodial lobes bilobed with outer lobe slightly shorter than inner lobe; subpodal flange and notch not developed ( Fig. 4E, G ). Chaetae crenulate capillaries in all parapodia; thoracic neuropodia bearing anterior row of curved weakly serrated uncini ( Fig. 4C, F ). Forked chaetae in abdominal notopodia not observed. Pygidium without anal cirri.

Distribution. Australia, Queensland, New South Wales.

Habitat. Not known.

Remarks. The studied specimens agree with the previous descriptions. They have a characteristic appearance, with a large size and short segments. Due to these characteristics, several specimens of S. cylindrifer from the collection of the Australian Museum, which looked somewhat similar, had been incorrectly identified as Scoloplos novaehollandiae . These two species are easily distinguishable by the branched branchiae (at least on posterior segments) and uniramous abdominal neuropodia in S. cylindrifer , whereas S. novaehollandiae has simple branchiae and bilobed abdominal neuropodia with subequal lobes.

Figures

FIGURE 4. Scoloplos novaehollandiae, AM G.11238. A–E: stereomicroscope, C–E: methylene blue staining; F, G: compound microscope. A. General view; B. Anterior end, dorsal view; C. Parapodia of chaetiger 2–6, lateral view; D. Thorax-abdomen transition, lateral view; E. Posterior part of abdomen, lateral view; F. Neuropodium of chaetiger 12 showing uncini (u); G. Parapodium of posterior abdominal chaetiger. br, branchia; ne, neuropodium; no, notopodium.