Protoariciella, Hartmann-Schroder, 1962

Zhadan, Anna, 2020, Review of Orbiniidae (Annelida, Sedentaria) from Australia, Zootaxa 4860 (4), pp. 451-502 : 499-500

Protoariciella (?) sp. B

Figure 29

Material examined. Western Australia: Fremantle, Arthur Head, off end of South Mole , 32°03’S, 115°44’E, depth 6 m, 25.12.1983, coll. J.K. Lowry, AM W.43258, 1 specimen on SEM stub .

Description. Specimen complete; body length about 2.5 mm, 45 chaetigers, width 270 µm ( Fig. 29A ). Transition from thorax to abdomen indistinct ( Fig. 29A ). Prostomium short, round; two peristomial segments ( Fig. 29B, C ). Branchiae starting from chaetiger 14, first triange-cirriform, then oval; shorter than notopodia ( Fig. 29B, E ). Notopodial postchaetal lobes digitiform; neuropodial lobes similar, but shorter; both lobes becoming shorter in abdomen ( Fig. 29 B–E). Pygidium with four short cirri ( Fig. 29F ). Notochaetae crenulated capillaries in all segments; forked chaetae absent ( Fig. 29 C–E). Neurochaetae crenulated capillaries in thorax, capillaries and one curved serrated hook in abdomen ( Fig. 29 C–E, G–J).

Remarks. This specimen is similar to Protoariciella (?) sp. A owing to chaetal shape and arrangement, while it differs owing to shorter thicker body and well developed neuropodial lobes. The specimen studied here likely represents a new species; but due to the few poorly preserved specimens and the limited knowledge of the important taxonomic characters in this genus, it is not described as a new species.

Figures

FIGURE 29. Protoariciella (?) sp. B, AM W.43258, SEM. A. General dorsal view; B. Anterior end, dorsal view; C. Anterior end, lateral view; D. Anterior parapodia, lateral view; E. Posterior parapodia, lateral view; F. Posterior end, ventro-lateral view; G–J. Abdominal neurochaetae. cc, crenulated capillaries; sh, serrated hook.