Nereis bifida Hutchings & Turvey, 1982

Hadiyanto, Hadiyanto, 2023, Nereididae (Annelida: Phyllodocida) from intertidal macroalgae in Western Australia, Zootaxa 5239 (2), pp. 151-203 : 163-164

Nereis bifida Hutchings & Turvey, 1982

Fig. 6A–G

Nereis bifida Hutchings & Turvey, 1982: 116–119 , fig. 9.a–c; Wilson 1985: 130–132, fig. 2.

Nereis (Nereis) bifida .— Hartmann-Schröder 1984: 27; Hartmann-Schröder 1990: 60.

Type locality. Speeds Point, near Streaky Bay , South Australia .

Material examined. Western Australia: False Cape Bosut, Bidyadanga , 18°34′18.40″S 121°43′42.87″E, 3 November 2020, 1 specimen ( WAM V11630 ) . Yardie Creek, Ningaloo , 22°19′35.90″S 113°48′33.70″E, 24 September 2020, 3 specimens ( WAM V11631 ) . Three Mile , 23°52′32.41″S 113°29′38.72″E, 23 September 2020, 2 specimens ( WAM V11632 ) .

Description. Complete specimens with 45–52 chaetigers, body 6.5–10.5 mm long and 0.4–0.8 mm wide; cream yellow in alcohol. Incomplete specimens with 31–47 chaetigers, posterior end missing, remaining body 6.0– 12.7 mm long and 0.5–0.7 mm wide; cream yellow to reddish brown in alcohol.

Prostomium as long as wide. Eyes black, two pairs, outer ones slightly larger, in trapezoidal arrangement. Palps one pair, palpophores globose, palpostyles conical. Antennae one pair, extending to level of palps. Tentacular cirri four pairs with basal articulation, longest one extending to chaetiger 2–3. Pharyngeal jaws yellow translucent, curved at tips, with eight teeth on each jaw. Paragnaths reddish to black, conical, present on both maxillary and oral rings, arranged as follows: Area I= 0, Area II= 1, Area III= 0, Area IV= 2–4 in one row, Area V= 0, Area VI= 0, Areas VII–VIII= 2–5 small, widely spaced, in one row ( Fig. 6A–B ).

Apodous segment as long as first chaetiger. First two chaetigers uniramous. Notopodia present with digitiform dorsal and ventral ligules, dorsal ligules reduced but still visible in posterior chaetigers. Dorsal cirri cirriform, attached on middle of dorsal parapodia, about 1.5 times longer than ventral ligules, similar length throughout chaetigers. Neuropodia with digitiform ventral ligules, acicular ligules, and triangular postchaetal lobes extending to same level of acicular ligule tips. Ventral cirri cirriform, attached basally on ventral parapodia, slightly shorter than ventral ligules, similar length throughout chaetigers ( Fig. 6C ).

Notochaetae present with homogomph spinigers in anterior chaetigers, homogomph falcigers ( Fig. 6D ) from chaetiger 19–27 for large specimens or chaetiger 11–16 for small specimens. Notopodial falcigerous blades long, slightly curved at tip, with terminal and one large lateral tooth, few smaller teeth basally in posterior chaetigers. Neurochaetae present with homogomph spinigers ( Fig. 6E ) and heterogomph falcigers in dorsal fascicles, heterogomph spinigers ( Fig. 6F ) and falcigers ( Fig. 6G ) in ventral fascicles. All spinigerous blades long, with fine serrations. Neuropodial falcigerous blades long, slightly curved, with fine serrations. Acicula black. Pygidium with anus on dorsal side, anal cirri cirriform, as long as last one to three chaetigers.

Remarks. Our specimens agree well with the original description of N. bifida ( Hutchings & Turvey 1982) . Wilson (1985) found that the longest tentacular cirri of N. bifida extended to chaetiger 2–7, longer than those of our specimens and the original description. Hartmann-Schröder (1990) found 10–11 teeth on each jaw, more teeth than our specimens and material examined by previous studies ( Hutchings & Turvey 1982; Wilson 1985). In small animals, dorsal notopodial ligules are absent in posterior chaetigers ( Hartmann-Schröder 1984).

Distribution. Temperate Australia: Western Australia, South Australia, Victoria, Tasmania, New South Wales ( Table 2 ).

Habitat. Intertidal, subtidal, rocky shores, seagrass beds ( Table 2 ).

Figures

FIGURE 6. Nereis bifida Hutchings &Turvey,1982 (WAMV11631);A, head,dorsal view; B, head, ventral view; C, parapodium, chaetiger 18, anterior view; D, notochaetae, homogomph falciger, chaetiger 21; E, neurochaetae, dorsal fascicle, homogomph spiniger, chaetiger 18; F, neurochaetae, ventral fascicle, heterogomph spiniger, chaetiger 18; G, neurochaetae, ventral fascicle, heterogomph falciger, chaetiger 10. Scale: A–B, 1 mm; C, 0.05 mm; D–G, 0.02 mm.