Nereis

Glasby, Christopher J., 2015, Nereididae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 207-239 : 223-224

Nereis sp. cf. N. trifasciata Grube, 1878

( Figs 3 H, 4A, B)

Nereis (Lycoris) trifasciata Grube, 1878: 74 –75.

? Nereis unifasciata .— Monro 1931: 13 –14. Non Willey, 1905.

Material examined. AM: W.43799, MI QLD 2335 (1); W.43839, MI QLD 2367 (1); W.43814, MI QLD 2344 (1); W.43806, MI QLD 2344 (1); W.43847-T, MI QLD 2375 (2); W.44307-T, MI QLD 2390 (1); W.43816, MI QLD 2344 (1); W.43818, MI QLD 2352 (3); W.43810, MI QLD 2335 (1); W.47592, MI QLD 2390 (2); W.47593, MI QLD 2371 (2); W.44507, MI QLD 2410 (1); W.47541-T, MI QLD 2436 (3); W.45433-T, MI QLD 2406 (1). NTM: W22550 (1), between Casuarina Beach and Palfrey Island, 14°40.92'S 145°26.83'E, coll. C. Glasby, 6 Apr 2008; W22554 (1), Big Vicky Reef, NW of Palfrey Island, 14°'S 145°'E, coll. E.K. Mills, 12 Apr 2008; W23902 (1), Turtle Beach, 14°39.153'S 145°27.042'E, coll. CReefs Lizard Island 10 Team, 7 Sept 2010; W23903 (1), MacGillivray Reef, 14°38.85'S 145°29.2739'E, coll. CReefs Lizard Island 10 Team, 3 Sept 2010; W23998 (1), Bommie Bay, 14°39.5898'S 145°28.272'E, coll. CReefs Lizard Team, 9 Sep 2010; NTM W22517 (1), SW of Palfrey Island, 14°41.65'S 145°27.93'E, coll. M. Ekins, 13 Apr 2008; NTM W22521 (1), Mermaid Cove, Lizard Island, 14°38.75'S 145°27.21' E, coll. C. Glasby, 6 Apr 2008; NTM W22623 (1), North Direction Island, 14°44.57'S 145°30.85'E, coll. C. Watson, 24 Feb 2009; NTM W22668 (1), Snake Pit, Lizard Island, 14°40.2'S 145°34.09'E, coll. J. Caley & S. Smith, 24 Feb 2009; NTM W22691 (1), Day Reef, 14°28.5'S 145°32.19'E, coll. S. Smith, 22 Feb 2009; NTM W22803 (1), North Direction Island, 14°44.81'S, 145°30.3'E, coll. C. Watson, 24 Feb 2009; NTM W23910 (1), Coconut Beach, 14°40.884'S, 145°28.35' E, coll. C. Watson, 7 Feb 2009; NTM W23970 (1), Bommie Bay, 14°39.5898'S 145°28.272'E, coll. CReefs Lizard 10 Team, 9 Sep 2010; W23983 (1), 14°44.718' S 145°30.2939' E, coll. CReefs Lizard 10 Team, 26 Sep 2010; NTM W24003 (1), Loomis Beach, 14°41.0298'S, 145°27.024'E, coll. CReefs Lizard 10 Team, 7 Sep 2010.

Diagnosis. Nereis species having dark brown band on chaetiger 2 and lighter brown bands on chaetigers 5 or 6 to 10–20; intensity and position of lighter posterior bands variable ( Fig. 3 H); two notopodial ligules; notopodial homogomph falcigers with relatively long serrated blades in posterior 1/3 to 1/4 of body occurring singly together with homogomph spinigers.

Remarks. The specimens examined here fit the concept of N. trifasciata used by other polychaete taxonomists working in the Indo-west Pacific, for example Fauvel (1953) and Wu et al. (1985); however, the pigmentation pattern of the Lizard Island specimens differ from that of the type which has three pronounced brown transverse bands on segments 2–4 (hence the specific name). Further, Grube (1878) did not mention the presence of notopodial falcigers, so the current generic assignment of his species is uncertain. The singly occurring notopodial homogomph falcigers in posterior parapodia of the present specimens appear to represent a replacement of one of the spinigers, rather than a de novo chaeta. It is an atypical feature for a Nereis species and in many respects this species has more in common with a Neanthes than a Nereis . The specimens examined may represent a new species. Nereis cf. trifasciata from Lizard Island is very similar to Neanthes unifasciata especially in terms of the general body pigmentation and paragnath pattern ( Figs 4A , B). The only apparent difference between the two species is that N. unifasciata lacks completely notopodial homogomph falcigers. Willey (1905: 271) also remarked on the similarity of the armature between the two species.

Habitat. Fore-reef and back-reef, lagoon, 1– 3 m.

Type locality. Bohol, Philippines.

Figures

FIGURE 3. A. Nereis cf. coutieri AM W. 43784, alive, lateral view; B. N. cf. coutieri AM W. 43832, alive, fluorescence image at 510 – 540 nm using DsRed fluorophore barrier filter, dorsal view; C. N. cf. coutieri NTM W 22570, preserved, antero-dorsal view; D. N. lizardensis AM W. 43798, alive, immature, dorsal view; E. N. lizardensis AM W. 44498, alive, fluorescence image at 510 – 540 nm using DsRed fluorophore barrier filter, dorsal view; F. N. lizardensis AM W. 44506, alive, mature male, dorsal view; G. N. lizardensis AM W. 44505, alive, mature female, dorsal view; H. N. trifasciata AM W. 43814, alive, dorsal view. Photo: Alexander Semenov (A, D, F – H). Approximate body widths: A: 0.8 mm; B: 0.7 mm; C: 0.3 mm; D: 0.9 mm; E: 1.0 mm; F: 2.3 mm; G: 2.4 mm; H: 2.0 mm.

FIGURE 4. A. Nereis trifasciata NTM W 22730, preserved, antero-dorsal view, pharynx everted; B. N. trifasciata NTM W 22730, preserved, antero-ventral view, pharynx everted; C. N. ‘ lizard _ NTM W 23960 ’ AM W. 43850, alive, dorsal view; D. N. ‘ mixed _ paragnaths _ NTM W 22634 ’ NTM W 22634, Heron Island, preserved, antero-dorsal view, pharynx everted; E. N. ‘ mixed paragnaths _ NTM W 22634 ’ NTM W 22634, Heron Island, preserved, antero-ventral view, pharynx everted; F. Perinereis nuntia species group AM W. 44302, alive, dorsal view; G. P. pictilis AM W. 43803, alive, dorsal view; H. P. pictilis alive, close up of AM W. 43803, antero-dorsal view. Photo: Alexander Semenov (C, F – H). Approximate body widths: A, B: 2.2 mm; C: 1.0 mm; D, E: 1.7 mm; F: 3.0 mm; G, H: 2.1 mm.