Nereis lizardensis Glasby, Wei & Gibb, 2013

Glasby, Christopher J., 2015, Nereididae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 207-239 : 221-223

Nereis lizardensis Glasby, Wei & Gibb, 2013

( Fig. 3 D–G)

Nereis lizardensis Glasby, Wei & Gibb, 2013: 255 –256, figs 4b, 5c, d.

Material examined. AM: W.47557, MI QLD 2398 (1); W.45291, MI QLD 2371 (1); W.43817, MI QLD 2352 (1); W.43813, MI QLD 2352 (1); W.43811, MI QLD 2340 (1); W.43778, MI QLD 2329 (3); W.43815-T, MI QLD 2340 (1); W.43786, MI QLD 2329 (5); W.43848, MI QLD 2375 (1); W.45489-T, MI QLD 2437 (3); W.43802-T, MI QLD 2337 (1); W.43805, MI QLD 2344 (1); W.44489-T, MI QLD 2397 (1); W.44319, MI QLD 2392 (1); W.44498-T, MI QLD 2393 (1); W.44506), MI QLD 2399 (1); W.44505, MI QLD 2399 (1); W.43845-T, MI QLD 2377 (1); W.44490-T, MI QLD 2393 (1); W.47547, MI QLD 2399 (1); W.44492, MI QLD 2399 (7); W.47565, MI QLD 2358 (1); W.43835, MI QLD 2340 (1); W.47556, MI QLD 2407 (8); W.47546, MI QLD 2397 (1); W.44869- T, MI QLD 2436 (1); W.45190-T, MI QLD 2446 (2); W.44488, MI QLD 2406 (1); W.43798, MI QLD 2335 (2); W.44499, MI QLD 2397 (1); W.47567, MI QLD 2390 (1). NTM: W23914 (1), North Direction Island, 14°44.718'S 145°30.2939'E, coll. CReefs Lizard 10 Team, 4 Sep 2010; W23930 (1), Turtle Beach, 14°39.1392'S 145°27.072'E, coll. CReefs Lizard 10 Team, 30 Aug 2010; W23932 (1), North Direction Island, 14°44.718'S 145°30.2939'E, coll. CReefs Lizard 10 Team, 26 Aug 2010; W23952 (1), Mrs Watson's Bay, 14°39.4332'S 145°27.042'E, coll. CReefs Lizard 10 Team, 27 Aug 2010; W23980 (1), 14°44.718'S 145°30.2939'E, coll. CReefs Lizard 10 Team, 26 Sep 2010; W24007 (1), Washing Machine, 14°23.4078'S 145°16.4616'E, coll. CReefs Lizard 10 Team, 11 Feb 2009; W24020 (1), High Rock, 14°49.56'S 145°33.1319'E, coll. CReefs Lizard 10 Team, 11 Sep 2010; W24021 (1), Palfrey Island, 14°41.0298'S 145°27.024'E, coll. CReefs Lizard 10 Team, 6 Sep 2010.

Diagnosis. Nereis species with abundant white pigment spots on head, postero-dorsally and on pygidium (white pigment spots absent at base of postero-dorsal tentacular cirri; Fig. 3 D); white pigment shows green fluorescence at 510–540 nm ( Fig. 3 E); few paragnaths in Area VII–VIII arranged in one line; notopodia with two ligules (ventral one reduced in size), and notopodial homogomph falcigers with one large lateral tooth and several smaller ones basally.

Remarks. Specimens from the NTM, collected on the CReefs trips, were previously identified as N. heirissonensis Augener, 1913 ; a review of these specimens shows that they are all small forms of N. lizardensis that have reduced numbers of paragnaths, especially in Areas III (1–3) and VI (0–3). Although the paragnath count in Areas III and IV would currently place them in N. heirissonensis , it appears that paragnath numbers are size related (as they were found to be for N. denhamensis by Hutchings & Turvey (1982)), and therefore that they are likely to be small forms of N. lizardensis . Unfortunately tissue samples do not exist for the specimens previously identified as N. heirissonensis so a DNA comparison must wait for further collecting.

Nereis lizardensis belongs to the Nereis denhamensis Augener, 1913 species group, which also includes Nereis heronensis ( Glasby et al. 2013) . As described for N. denhamensis , the present specimens also showed that juveniles have a reduced dorsal notopodial ligule (half the size of the ventral notopodial ligule), and fewer paragnaths in Area III, which are arranged in a line rather than a patch of two or more rows.

The present specimens show greater variation in epitokal morphological features than has been previously described. Mature male epitokes (e.g., AM W.44506) with slightly enlarged eyes and a pre-natatory region of 14 chaetigers as described by Glasby et al. (2013); however, the ventral cirrus lamellae and ventral cirrus lobes of natatory chaetigers described by these authors were not observed in the present specimens ( Fig. 3 F). Mature female epitoke (AM W.44505) with tightly packed green eggs in the coelom of mid-body segments ( Fig. 3 G); also in this specimen the epitokal conical postchaetal lamella start on chaetiger 19 rather than on chaetiger 17 in the specimens examined by Glasby et al. (2013) and disappear about 10 chaetigers from the pygidium.

Habitat. Lagoon, fore-reef, back-reef and reef slope; associated with coral rubble, sand and Halimeda ; 1– 15 m.

Type locality. Turtle Beach, Lizard Island.

Distribution. Northern Australia, 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.