Notch-head Marblefish, Aplodactylus etheridgii (Ogilby 1889)

Other Names: Notchheaded Marblefish

A Notch-head Marblefish, Aplodactylus etheridgii, at Lord Howe Island in the Tasman Sea. Source: Graham Edgar / Reef Life Survey. License: CC By Attribution

A brownish-green marblefish with a greyish abdomen, brown fins, numerous small white spots on lower sides and fins, the outer half of the fleshy pectoral-fin rays yellowish-white and yellow gill cover membranes.

Cite this page as:
Bray, D.J. 2020, Aplodactylus etheridgii in Fishes of Australia, accessed 28 Nov 2022,

Notch-head Marblefish, Aplodactylus etheridgii (Ogilby 1889)

More Info


Found at Lord Howe Island and Norfolk Island in the Tasman Sea; also at the Kermadec Islands, northern New Zealand. 


Dorsal fin XV-XVII, 19-20; Anal fin III, 6-7; Pectoral fin i, 13-14; Lateral line scales 83-98; Gill rakers 4-8 + 11-16 = 18-20; Vertebrae 15-19 = 34.

Body elongate, greatest depth 3.5-4.2 in SL; head length 3.7-4.5 in SL; snout short, 2.8-3.1 in head; dorsal profile of head obtuse, larger specimens with bony protuberance above eye; orbital diameter 4.3-5.1 in head; interorbital space distinctly concave, least width of interorbital 3.6-4.4 in head; least depth of caudal peduncle 2.0-2.8 in head; peduncle length 1.8-3.2 in head. Mouth small, somewhat ventral on head; lips fleshy, upper lip projecting, maxilla reaching a vertical through posterior nostril; teeth small, mainly multicuspid, a few tricuspid, in three to four rows in jaws, outermost row of teeth largest; vomerine teeth present as two small patches; two pairs of nostrils, anterior pair with fleshy fimbriate flaps on anteroventral margin and posteroventral margin; opercle with broad flat embedded spine which does not extend to the fleshy margin. 

Dorsal fin long-based, with elongate notch between spinous and soft parts of fin, basal length of soft dorsal fin 0.9-1.1 in length of spinous part; anal fin short, basal length 1.8-2.9 in head; pectoral fin length 1.0-1.3 in head, ventral-most 5 to 6 rays simple, fleshy; pelvic fin length 0.9-1.4 in head, rays fleshy.

Scales small, cycloid, embedded, extending on to cheeks and opercles, and forming a sheath along base of spinous dorsal fin.


Body and head brownish-green, abdomen grey, fins brown; lower parts of body and fins with numerous small white spots; outer half of fleshy pectoral rays yellowish white; branchiostegal membrane yellow.


Feeds on algae.

Similar Species

Differs from other species in the genus by the distinctly concave interorbital space and profile of head notched behind the eye.

Species Citation

Haplodactylus etheridgii Ogilby 1889, Memoirs of the Australian Museum 2(3): 57. Type locality: Admiralty Islets, Lord Howe Island.


Bray, D.J. 2020


Atlas of Living Australia

Notch-head Marblefish, Aplodactylus etheridgii (Ogilby 1889)


Allen, G.R., Hoese, D.F., Paxton, J.R., Randall, J.E., Russell, B.C., Starck, W.A., Talbot, F.H. & Whitley, G.P. 1976. Annotated checklist of the fishes of Lord Howe Island. Records of the Australian Museum 30(15): 365-454 figs 1-2 

Ayling, T. & Cox, G.J. 1982. Collins Guide to the Seafishes of New Zealand. Auckland : Collins 343 pp. 48 pls 475 figs. 

Burridge, C.P. 2000. Molecular phylogeny of the Aplodactylidae (Perciformes: Cirrhitoidea), a group of Southern Hemisphere marine fishes. Journal of Natural History 34(11): 2173-2185.

Cole, R.G. 2001. Patterns of abundance and population size structure of herbivorous fishes at the subtropical Kermadec Islands and in mainland New Zealand. New Zealand Journal Marine and Freshwater Research 35: 445-456.

Eddy, T.D. 2011. Recent observations of reef fishes at the Kermadec Islands marine reserve, New Zealand. New Zealand Journal Marine and Freshwater Research 45(1): 153-159.

Francis, M. 1993. Checklist of the coastal fishes of Lord Howe, Norfolk, and Kermadec Islands, southwest Pacific Ocean. Pacific Science 47(2): 136-170 figs 1-2 

Francis, M. 2001. Coastal Fishes of New Zealand. Auckland : Reed Publishing (NZ) 3rd edn, 103 pp. 

Francis, M.P., Grace, R.V. & Paulin, C.D. 1987. Coastal fishes of the Kermadec Islands. Zealand Journal Marine and Freshwater Research 21(1): 1-13.

Ogilby, J.D. 1889. The reptiles and fishes of Lord Howe Island. Memoirs of the Australian Museum 2(3): 51-74 pls 2-3 DOI 10.3853/j.0067-1967.2.1889.481 See ref online

Paulin, C., Stewart, A., Roberts, C. & McMillan, P. 1989. New Zealand fish: a complete guide. National Museum of New Zealand Miscellaneous Series 19: 1-279 

Russell, B.C. 2000. Review of the southern temperate fish family Aplodactylidae (Pisces: Perciformes). Journal of Natural History 34: 2157-2171.

Stewart, A.S. 2015. 198 Family Aplodactylidae. pp. 1344-1346 in Roberts, C.D., Stewart, A.L. & Struthers, C.D. (eds). The Fishes of New Zealand. Wellington : Te Papa Press Vol. 4 pp. 1153-1748.

Waite, E.R. 1904. Additions to the fish-fauna of Lord Howe Island. No. 4. Records of the Australian Museum 5(3): 135-186 fig. 32 pls 17-24

Quick Facts

CAAB Code:37376003

Depth:6-20 m

Habitat:Reef associated

Max Size:45 cm TL

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Species Maps

CAAB distribution map