Micronereis halei Hartman, 1954

Hadiyanto, Hadiyanto, 2023, Nereididae (Annelida: Phyllodocida) from intertidal macroalgae in Western Australia, Zootaxa 5239 (2), pp. 151-203 : 158-159

Micronereis halei Hartman, 1954

Fig. 3B–E

Micronereis halei Hartman, 1954: 25–26 , figs 18–21; Hutchings & Turvey 1982: 104, fig. 4a; Paxton 1983: 13–14, figs 31–33; Hartmann-Schröder 1983: 140; Hartmann-Schröder 1984: 30; Hartmann-Schröder 1986: 50.

Type locality. Sellicks Beach , South Australia .

Material examined. Western Australia: Cosy Corner Beach , 34°15′25.83″S 115°1′43.23″E, 14 December 2020, 1 specimen ( WAM V11624 ) .

Description. A complete specimen with 24 chaetigers, body 4.5 mm long and 0.5 mm wide; cream yellow in alcohol.

Prostomium as long as wide. Eyes black, two pairs, equal size, in trapezoidal arrangement. Palps minute, simple, directed ventrally. Antennae absent. Tentacular cirri four pairs, smooth, longest one extends to chaetiger 3 ( Fig. 3B ).

Apodous segment reduced. First chaetiger uniramous. Notopodia and neuropodia widely separated, comprising a single lobe each, subtriangular distally. Dorsal and ventral cirri cirriform, attached subdistally and basally, respectively, on parapodia, both similar length throughout chaetigers. Accessory parapodial cirri absent ( Fig. 3C ).

Notochaetae and neurochaetae present with homogomph spinigers, shafts without septa. Spinigerous blades long, smooth, with fine tips ( Fig. 3D ) and some with sub-spherical caps ( Fig. 3E ). Pygidium present with short anal cirri, conical, as long as last chaetiger.

Remarks. This specimen is juvenile. The adult species have 27 chaetigers ( Paxton 1983). Micronereis halei has accessory parapodial cirri on the ventral side of the notopodia and the dorsal side of the neuropodia ( Hartman 1954), but we and Hartmann-Schröder (1983; 1986) cannot find those cirri perhaps due to them being juvenile specimens ( Paxton 1983) or females ( Hartmann-Schröder 1983). In our specimen and materials examined by Hartman (1954), spinigers are smooth, instead of serrated ( Hartmann-Schröder 1983). Chaetae may also consist of homogomph falcigers ( Paxton 1983), but we agree that those are modified homogomph spinigers with sub-spherical caps ( Fig. 3E ) as also observed by Hutchings & Turvey (1982).

Distribution. Temperate Australia: South-West Australia, South Australia, Victoria ( Table 2 ).

Habitat. Intertidal, rocky shores ( Table 2 ).

Figures

FIGURE 3. Micronereis bansei (Hartmann-Schröder, 1979) (WAM V11623); A, notochaetae, homogomph spiniger, chaetiger 7. Micronereis halei Hartman, 1954 (WAM V11624); B, head, dorsal view; C, parapodium, chaetiger 10; D, notochaetae, homogomph spiniger, chaetiger 10; E, notochaetae, homogomph spiniger with sub-spherical cap, chaetiger 10 Scale: A, 0.01 mm; B, 0.5 mm; C, 0.05 mm; D–E, 0.01 mm.