Port Jackson Glassfish, Ambassis jacksoniensis (Macleay 1881)

Other Names: Port Jackson Perchlet

A Port Jackson Glassfish, Ambassis jacksoniensis, at The Pipeline, Port Stephens, New South Wales, May 2019. Source: Erik Schlogl / iNaturalist.org. License: CC by Attribution-NonCommercial

Summary:

A small, translucent to silvery perch-like fish with a deeply notched dorsal fin. Port Jackson Glassfish form schools in estuaries and sheltered coastal waters.

Cite this page as:

Bray, D.J. & Thompson, V.J. 2021, Ambassis jacksoniensis in Fishes of Australia, accessed 03 Apr 2025, https://fishesofaustralia.net.au/home/species/4646

Port Jackson Glassfish, Ambassis jacksoniensis (Macleay 1881)

More Info

Distribution	Known only from the Burnett River, Queensland, to the Gippsland Lakes, Victoria. Forms large schools in lakes, coastal inlets, estuaries, mangrove-lined creeks, and sheltered coastal waters. Divers often see schools sheltering beneath jetties, and along breakwalls in tidal channels.
Features	Dorsal fin Vll + I,9-11; Anal fin III, 9; Pectoral fin 14; Pelvic fin I, 5. Body laterally compressed, relatively slender; maximum body depth 29.2 to 33.2% of SL; head length 32.0 to 34.0% of SL; head profile steep; eye diameter 11.8 to 12.6; lower opercle and preopercle with small spines; mouth oblique; teeth conical, present in jaws, vomer and palatines; lateral line continuous; lateral line scales 27-29; gill rakers on lower limb of first arch 19 to 23; 1 supraorbital spine (rarely 2); nasal spine present; preorbital ridge smooth to slightly crenulate; suborbital smooth or slightly crenulate; preorbital edge with 4 to 7 serrae; preopercular ridge with 2 to 4 serrae; lower edge of preoperculum with 9 to 13 serrae, hind margin smooth; interoperculum smooth. Large, cycloid scales on body and head; vertical scale rows 27 to 29; horizontal scale rows 10 or 11; 2 scale rows on cheek. Dorsal fin short-based, tall spinous section with a small spine anteriorly; spinous dorsal 18.9 to 22.9% height of SL; dorsal fin deeply notched before last spine with soft rays posteriorly; anal fin with small spine anteriorly followed by two long spines; dorsal and anal fins with a scaly sheath at the base; caudal fin forked, lobes rounded; fin spines relatively weak and flexible.
Size	To 7 cm SL
Colour	Semi-transparent to silvery. In preservative: generally pale tan or yellowish peppered with melanophores on scale margins of upper side; scales darklv pigmented along base of dorsal and anal fins, and on upper and lower edges of caudal peduncle; a thin black stripe along middle of side, particularly evident on posterior half of body; operculum silvcry; fins mainly translucent.
Feeding	Feeds on zooplankton from near the surface to the substrate. The species is preyed on by cormorants.
Remarks	When preserved in alcohol this species is generally pale tan or yellowish peppered with melanophores on scale margins of upper side. Scales are darkly pigmented along base of dorsal and anal fins, and on upper and lower edges of caudal peduncle. A thin black stripe along middle of side can be seen on the posterior end of the body. Fins are mainly translucent.
Similar Species	The Port Jackson Glassfish is most similar to the Estuary Glassfish, Ambassis marianus. The two species can be readily separated on body depth (33-38% SL, compared with 37-44% in A. marianus). A. marianus also has a multi-serrate supraorbital spine (vs the single small supraorbital spine of A. jacksoniensis), and the lateral line of A. jacksoniensis is continuous whereas that of A. marianus is interrupted in the middle portion.
Etymology	The species is named jacksoniensis in reference to the type locality Port Jackson, New South Wales.
Species Citation	Pseudambassis jacksoniensis Macleay 1881, Proc. Linn. Soc. N.S.W. (1)5(3): 340. Type locality: Port Jackson, New South Wales.
Author	Bray, D.J. & Thompson, V.J. 2021
Resources	Atlas of Living Australia Australian Faunal Directory Catalog of Fishes

Port Jackson Glassfish, Ambassis jacksoniensis (Macleay 1881)

References

Allen, G.R. 1999. Family Ambassidae. pp. 2433-2435 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 4 pp. 2069-2790.

Allen, G.R. & Burgess, W.E. 1990. A review of the glassfishes (Chandidae) of Australia and New Guinea. Records of the Western Australian Museum 34: 139-206. See ref online

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Kuiter, R.H. 1993. Coastal fishes of south-eastern Australia. Crawford House Press : Bathurst 437 pp.

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Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3)

Macleay, W.J. 1881. Descriptive catalogue of the fishes of Australia. Part 1. Proceedings of the Linnean Society of New South Wales 5 (3): 302–444. See ref at BHL

Mazumder, D., Saintilan, N. & Williams, R.J. 2006. Fish assemblages in three tidal saltmarsh and mangrove flats in temperate NSW, Australia: a comparison based on species diversity and abundance. Wetlands Ecology and Management 14: 201-209 https://doi.org/10.1007/s11273-005-7887-4

Mazumder, D., Saintilan, N. & Williams, R.J. 2006. Trophic relationships between itinerant fish and crab larvae in a temperate Australian saltmarsh. Marine and Freshwater Research 57: 193-199 https://doi.org/10.1071/MF05040

Mazumder, D., Williams, R.J., Reid, D., Saintilan, N. & Szymczak, R. 2008. Variability of stable isotope ratios of glassfish (Ambassis jacksoniensis) from mangrove/saltmarsh environments in southeast Australia and the implications for sample size. Environmental Bioindicators 3: 114–123 https://doi.org/10.1080/15555270802266003

Miskiewicz, A.G. 1987. Taxonomy and ecology of fish larvae in Lake Macquarie and New South Wales coastal waters. University of New South Wales, Sydney. Ph.D. thesis.

Neira, F.J., A.G. Miskiewicz & T. Trnski, 1998. Larvae of temperate Australian fishes: laboratory guide for larval fish identification. University of Western Australia Press. 474 pp.

Whitley, G.P. 1935. Fishes from Princess Charlotte Bay, North Queensland. Records of the South Australian Museum 5(3): 345-365 figs 1-11 as Velambassis jacksoniensis) See ref at BHL