Micronephthys oculifera Mackie, 2000

Murray, Anna, Wong, Eunice & Hutchings, Pat, 2015, Nephtyidae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia, Zootaxa 4019 (1), pp. 414-436 : 421-423

Micronephthys oculifera Mackie, 2000

( Figs 4–5 )

Micronephthys oculifera Mackie, 2000: 518 –524, figs 1–4.

Material examined. Queensland, Lizard Island: AM W.45039 (2), AM W.46977 (1), MI QLD 2441; AM W.45170 (8), AM W.46979 (2), MI QLD 2440; AM W.46978 (1), MI QLD 2443; AM W.46984 (1), MI QLD 2366; AM W.46985 (3), MI QLD 2432; AM W.46986 (1), MI QLD 2421; AM W.46987 (1), MI QLD 2433; AM W.47227 (2), 100 m off Mangrove Beach, 14°40'S, 145°28'E, sand, 3 m, 30 Sep 1978; AM W.47399 (4), 100 m off eastern end of Mangrove Beach, 14°40'S, 145°28'E, sand, 3.6 m, 11 Oct 1978.

Other material examined. New South Wales, Port Stephens area, 32°42'S, 152°10'E: AM W.41579 (1), AM W.41541 (2), AM W.41578 (1, lateral photograph), AM W.43653 (1 on SEM), AM W.43574 (2), AM W.41514 (1), AM W.41543 (1), AM W.41544 (3, 1 anterior dorsal photograph), AM W.41545 (1), AM W.41540 (4), AM W.41577 (1), AM W.41580 (1), AM W.41519 (1), AM W.41518 (1 on SEM), AM W.41511 (1), AM W.41515 (1), AM W.41516 (3), AM W.41546 (1), AM W.41517 (2), AM W.41512 (1), AM W.41576 (1), AM W.41472 (1), AM W.41542 (2), AM W.41582 (1 on SEM); Hawkesbury River area, 33°33'30"S, 151°14'E: AM W.23988 (1), AM W.23983 (1), AM W.23984 (3), AM W.23985 (1), AM W.23986 (2), AM W.23987 (3); Pittwater area, 33°35'40"S, 151°18'30"E: AM W.32509 (1), AM W.23979 (2), AM W.23982 (4), AM W.23977 (4), AM W.23976 (4), AM W.23975 (6), AM W.23980 (2), AM W.23981 (6), AM W.23978 (3); Botany Bay, 33°58'11"S, 151°11'10"E: AM W.23974 (1), sandy mud, 18.4 m, Dec 1994. Hong Kong: 1 paratype of M. oculifera , NMW Z.1986.079.0158, Hoi Ha Wan, west of Ngan Chau (Flat Island), 22°28'44"N, 114°19'48"E, silty fine to medium sand between corals, 4 m, Apr 1986; 1 paratype of M. oculifera , NMW Z.1986.079.0164, east side of Wang Mun Hoi (Deep Pass) near Tai Kok Tau (northwest point of Crescent Island), 22°31'59"N, 114°18'26"E, heterogeneous shell sand and gravel with silt and organic matter, 4 m, Apr 1986.

Description. Complete, preserved specimens from Lizard Island range from 3–12 mm long, 0.4–1.2 mm wide, for 20–55 chaetigers. Prostomium as long as wide in specimens with pharynx not everted, antennae and palps conical with swollen tips, antennae with wide separation, palps inserted ventrolateral to antennae on prostomium ( Figs 4 A, 5A). Nuchal pits round ( Fig. 5 A). Two pairs of overlapping lensed eyes present on prostomium ( Fig. 4 A), in some older preserved specimens these are faded to light red/orange; in some specimens dark pigment spots present in small patch between antennae ( Fig. 4 A–B). Pharynx with 10 pairs of bifid terminal papillae and 22 subterminal longitudinal rows of 8–9 papillae ( Fig. 4 B–C); single middorsal subterminal papilla absent, verrucae present proximally. Branchiae absent but ciliated patches present on margins of interramal space ( Figs 4 C, 5C). Dorsal and ventral cirri small, pyriform ( Fig. 5 C), except on chaetiger 1, with ventral cirri similar in shape and length to palps and antennae ( Fig. 5 A), dorsal cirri half as long and cirriform, tapering. Parapodial lobes all reduced; anteriorly, acicular lobes conical ( Fig. 5 C), preacicular lobes rounded, postacicular lobes bluntly conical; midbody acicular lobes conical, preacicular lobes rounded, postacicular lobe rounded on notopodia, absent from neuropodia; posteriorly notopodial pre- and postacicular lobes rounded, neuropodial postacicular lobe absent, preacicular lobe rounded. Aciculae with distally curved tips. Chaetae of 4 types: smooth capillaries present only in neuropodia of chaetiger 1; barred ( Fig. 5 D–F) in preacicular positions in noto- and neuropodia (except neurochaetiger 1); lyrate with unequal rami and spinose blades, in postacicular position ( Fig. 5 E–F), starting from chaetigers 4–8; spinose capillaries in post-acicular position ( Fig. 5 D–E). Pygidium with single thick terminal cirrus ( Fig. 5 B).

Remarks. The Lizard Island specimens agree well with Mackie’s (2000) type material originally collected from Hong Kong waters. However, we did not observe what Mackie (2000) describes as “broad-bladed serrated chaetae” which he notes were present in juvenile specimens. Some specimens collected in 1978 from Lizard Island were originally noted to be “yellow” in colour, but have since lost all colouration, including eye pigment; some specimens from N.S.W. display orange-pigmented dorsolateral longitudinal stripes along the body which fade with preservation and remain as granular stripes, most conspicuous from about chaetiger 10 onwards to posterior segments, and also possess aciculae with red tips which just emerge from the parapodial lobes.

This species has not previously been reported from Australia but appears to be widespread and abundant along the east coast of Australia, and has probably only ever been recorded as Micronephthys sp. in many ecological studies, from the 1970s onwards. Some specimens were collected from Lizard Island in 1978, which pre-dates the original description of this species from Hong Kong by Mackie (2000).

Habitat. Sandy mud, muddy sand, and sand, associated with seagrass, algae and soft corals, in intertidal and shallow subtidal depths.

Distribution. Hong Kong, Australia (Queensland, New South Wales).

Figures

FIGURE 4. Micronephthys oculifera, specimens stained with methyl blue. A. Anterior end, dorsal view, AM W. 41544; B. Anterior end, dorsal view, pharynx everted, AM W. 41511; C. Anterior end, lateral view, AM W. 41578. Abbreviations: an = antenna, e = eye, cp = ciliated patches, p = palp. Scale bars: A – C = 0.1 mm.

FIGURE 5. Micronephthys oculifera, SEM photos, AM W. 43653 (A – C), AM W. 41518 (D – F). A. Anterior end, dorsal view; B. Posterior end, ventral view; C. Chaetigers 12 – 13, lateral view; D. Barred and spinose chaetae, chaetiger 36; E. Barred and lyrate chaetae, inset with magnification of spinose chaetae, chaetiger 20; F. Postacicular lyrate chaetae, chaetiger 21. Abbreviations: b = barred chaeta, cp = cilia patch, dc = dorsal cirrus, ly = lyrate chaeta, pyc = pygidial cirrus, sp = spinose chaeta. Scale bars: A = 0.1 mm, B – C = 0.05 mm, D – F = 0.01 mm except for enlarged image 2 µm.