Perinereis helleri ( Grube, 1878 )

Hadiyanto, Hadiyanto, 2023, Nereididae (Annelida: Phyllodocida) from intertidal macroalgae in Western Australia, Zootaxa 5239 (2), pp. 151-203 : 174-175

Perinereis helleri ( Grube, 1878)

Figs 12A–F , 20A–B

Nereis (Perinereis) helleri Grube, 1878: 81–82 .

Perinereis helleri .—Monro 1931: 14–15, fig. 8a–c; Russell 1962: 7; Wu 1967: 66; Rozbaczylo & Castilla 1973: 220–221; Hartmann-Schröder 1979: 116, figs 199–202; Hutchings et al. 1991: 254–255, fig. 9a–c; Pamungkas & Glasby 2015: 15–17, fig. 6A–B.

Type locality. Bohol, Philippines .

Material examined. Western Australia: Lighthouse Bay, Ningaloo , 21°48′19.86″S 114° 7′48.61″E, 26 September 2020, 1 ( WAM V11664 ) . Three Mile , 23°52′32.41″S 113°29′38.72″E, 23 September 2020, 1 specimen ( WAM V11665 ) .

Comparative material. Perinereis helleri , det. C. Glasby, Fishermans Wharf, Darwin Harbour , Northern Territory, 12°29′S 130°52′E, intertidal, under rocks and in crevices, coll. C.J. Glasby & P. Schroeder, 3 August 2004, 1 ( NTM W19020 ) .

Description. Incomplete specimens with 33–35 chaetigers, posterior end missing, remaining body 9.3–27.2 mm long and 0.9–2.8 mm wide; cream yellow in alcohol.

Prostomium as long as wide. Eyes black, two pairs, equal sizes, in trapezoidal arrangement. Palps one pair, palpophores globose, palpostyles conical. Antennae one pair, shorter than palps. Tentacular cirri four pairs with basal articulation, longest ones extending to chaetiger 5. Pharyngeal jaws reddish black, curved at tips, with eight teeth on each jaw. Paragnaths reddish black, present on maxillary and oral rings, arranged as follows: Area I= 5–6 cones, Area II= 10–12 cones in three curved rows, Area III= 9–13 cones with 2 cones at lateral of main group, Area IV= 17–20 cones, Area V= 3 cones in a triangle, Area VI= 1 smooth bar, Areas VII–VIII= 42–44 cones in two rows ( Fig. 12A–B ).

Apodous segment slightly longer than first chaetiger. First two chaetigers uniramous. Notopodia present with subconical dorsal and ventral ligules in anterior chaetigers, become digitiform in posterior chaetigers. Notopodial ligules not greatly expanded posteriorly. Dorsal cirri cirriform, attached on middle of dorsal parapodia, as long as dorsal ligules. Neuropodia with subconical ventral ligules, acicular ligules, and rounded postchaetal lobes extending to same level of acicular ligule tips; ventral ligules become digitiform in posterior chaetigers. Ventral cirri cirriform, attached basally on ventral parapodia, shorter than ventral ligules, similar length throughout chaetigers ( Fig. 12C ).

Notochaetae present with homogomph spinigers. Neurochaetae heterogomph falcigers ( Fig. 12D ) and homogomph spinigers ( Fig. 12E ) in dorsal fascicles, heterogomph falcigers and spinigers ( Fig. 12F ) in ventral fascicles. Homogomph spinigerous blades long, with fine serrations, longer than heterogomph spinigerous blades. Falcigerous blades long, with fine serrations. Acicula black.

Remarks. The specimen examined here fits the description of the species by Hutchings et al. (1991), except for the shorter posterodorsal tentacular cirri (only extending to chaetiger 5 vs. to chaetiger 8–16 and having more paragnaths in Area I (5–6 vs. 1–2). However, comparative material from Darwin Harbour, Northern Territory showed intermediate numbers of paragnaths in Area I (3), while having the longer posterodorsal tentacular cirri (at least to chaetiger 12) ( Fig. 20A–B ), thus we view the differences as intraspecific variation. Our specimens from Ningaloo and Three Mile extend to the southerly distribution of this species, which was previously reported only as far south as Enderby Island (20°36′S).

Distribution. Indo-Pacific: Taiwan, Philippines, Indonesia, Australia, Chile ( Table 2 ).

Habitat. Intertidal, subtidal, mudflat, rocky shores.

Figures

FIGURE 12. Perinereis helleri (Grube, 1878) (WAM V11664); A, head, dorsal view; B, head, ventral view; C, parapodium, chaetiger 35, posterior view; D, neurochaetae, dorsal fascicle, heterogomph falciger, chaetiger 7; E, neurochaetae, dorsal fascicle, homogomph spiniger, chaetiger 7; F, neurochaetae, ventral fascicle, heterogomph spiniger, chaetiger 22. Scale: A–B, 0.5 mm; C, 0.1 mm; D–F, 0.02 mm.

FIGURE 20. Comparative material from Western Australia and the Northern Territory sourced from the Museum & Art Gallery of the Northern Territory. Perinereis helleri (Grube, 1878) (NTM W19020; 2.0 mm wide at chaetiger 1): A, head, dorsal view; B, head, ventral view. Perinereis variodentata (Augener, 1913) (NTM W18369; 1.8 mm wide at chaetiger 1): C, anterior segments, dorsal view; D, proboscis, ventral dissection. Platynereis polyscalma Chamberlin, 1919 (NTM W19031; 2.8 mm wide at chaetiger 1): E, anterior segments, dorsal view; F, proboscis, ventral dissection. Platynereis uniseris Hutchings & Reid, 1991 (NTM W19003; 1.4 mm wide at chaetiger 1): A, anterior segments, dorsal view; B, proboscis, ventral dissection.