Longspine Glassfish, Ambassis interrupta Bleeker 1852

Other Names: Interrupta Glassy Perchlet, Long-spined Glassfish, Long-spined Perchlet, Northern Perchlet, Sailfin Perchlet

Summary:

With a brilliant white patch on the outer part of the membrane between the second and third anal-fin spines.

Cite this page as:

Bray, D.J. 2025, Ambassis interrupta in Fishes of Australia, accessed 02 Jul 2025, https://fishesofaustralia.net.au/home/species/1583

Longspine Glassfish, Ambassis interrupta Bleeker 1852

More Info

Distribution	Fitzroy River, The Kimberley, Western Australia, to Townsville, Queensland. Elsewhere the species is widespread in Indo-west Pacific: west coast of India and the Andaman Islands, to Indonesia and the Philippines, north to southern Japan, south to New Caledonia and Vanuatu. Inhabits freshwater, brackish and marine environments, including the lower reaches of freshwater rivers, streams, lakes, estuaries and brackish mangroves. Although mostly occurring within 20 km of the sea, it has been found at least 230 km upstream in the Lower Fly River, Papua New Guinea. Often forms aggregations among mangrove roots or log debris.
Features	Dorsal fin VII + I, 9-10; Anal fin III, 9-10; Pectoral fin 14-16; Lateral line scales 11-13 + 9-13, interrupted in mid-portion by about 3 to 6 tubeless scales; Vertical scale rows from upper edge of gill opening to caudal fin base 27-28; Horizontal scale rows from anal fin origin to base of dorsal fin 10; Transverse scale rows on cheek 2; Predorsal scales 13-16. Body deep, depth 37.2-47.8 %SL; head length 35.8 to 42.3 %SL; second dorsal-fin spine robust, elongate. A single supraorbital spine; nasal spine well developed; preorbital ridge with 3-6 small serrae; suborbital smooth; preorbital edge with 5-8 serrae; preopercular ridge with 9-20 serrae on lower limb, vertical limb smooth; lower edge of preoperculum with 13-25 serrae, hind margin smooth; interoperculum with 2-10 moderate to weakly developed serrae.
Feeding	Feeds on crustaceans, polychaete worms, terrestrial and aquatic insects, and small fishes.
Biology	Mostly spawns in estuarine and marine waters.
Etymology	The specific name is from the Latin interruptus (= interrupted, to break apart, break off), in reference to the interrupted lateral line of this species.
Species Citation	Ambassis interrupta Bleeker 1852, Natuurkundig Tijdschrift voor Nederlandsch Indië 3: 696. Type locality: Wahai, Ceram and Jakarta, Java, Indonesia.
Author	Bray, D.J. 2025
Resources	Atlas of Living Australia Australian Faunal Directory Catalog of Fishes

Longspine Glassfish, Ambassis interrupta Bleeker 1852

References

Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Perth : Western Australian Museum 292 pp. 106 pls.

Allen, G.R. & Burgess, W.E. 1990. A review of the glass-fishes (Ambassidae) of Australia and New Guinea. Records of the Western Australian Museum, Supplement 34: 139-206

Allen, G.R. & Coates, D. 1990. An ichthyological survey of the Sepik River, Papua New Guinea. Records of the Western Australian Museum Suppl. No. 34: 31-116.

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.

Allen, G.R., Storey, A.W. & Yarrao, M. 2008. Freshwater Fishes of the Fly River Papua New Guinea. Tabubil, Papua New Guinea : Ok Tedi Mining 216 pp.

Allen, G.R. & Swainston, R. 1988. The Marine Fishes of North-Western Australia. A field guide for anglers and divers. Perth, WA : Western Australian Museum vi 201 pp., 70 pls.

Anderson, M.E. & Heemstra, P.C. 2003. Review of the glassfishes (Perciformes: Ambassidae) of the western Indian Ocean. Cybium 27(3): 199-209

Anderson, M.E. & Heemstra, P.C. 2022. Family Ambassidae, Glassfishes, pp 18-23 in Heemstra, P.C., Heemstra, E., Ebert, D.A., Holleman, W. & Randall, J.E. (eds). Coastal fishes of the western Indian Ocean. Volume 3. Makhanda, South Africa : South African Institute for Aquatic Biodiversity, i-ii, 1-469, i-xi, Pls. 1-158.

Bleeker, P. 1852. Nieuwe bijdrage tot de kennis der ichthyologische fauna van Ceram. Natuurkundig Tijdschrift voor Nederlandsch Indië 3: 689-714

Coates, D. 1990. Aspects of the biology of the perchlet Ambassis interrupta Bleeker (Pisces: Ambassidae) in the Sepik River, Papua New Guinea. Australian Journal of Marine and Freshwater Research 41: 267-274.

Dahanukar, N., Palmer-Newton, A., Torres, A.G. & Kesner-Reyes, K. 2021. Ambassis interrupta. The IUCN Red List of Threatened Species 2021: e.T172393A60616867. https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T172393A60616867.en. Accessed on 20 May 2024.

Ghazali, S.F., Lavoué, S., Alshari, N. F. M. A. H., Abidin, D. H. Z., et al. 2023. Cracking the glass-perchlet code: Integrative taxonomy uncovers high species-level diversity within the glass-perchlet genus Ambassis (Ambassidae) in tropical Asia. Zoologica Scripta 53: 157-174 https://doi.org/10.1111/zsc.12640

Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

Hitchcock, G. 2002. Fish Fauna of the Bensbach river, southwest Papua New Guinea. Memoirs of the Queensland Museum 48(1): 119-122.

Larson, H.K. & Williams, R.S. 1997. Darwin Harbour fishes: a survey and annotated checklist. pp. 339-380 in Hanley, H.R., Caswell, G., Megirian, D. & Larson, H.K. (eds). The Marine Flora and Fauna of Darwin Harbour, Northern Territory, Australia. Proceedings of the Sixth International Marine Biology Workshop. Darwin : Museum and Art Gallery of the Northern Territory 466 pp.

Macleay, W.J. 1881. Descriptive catalogue of the fishes of Australia. Part 1. Proceedings of the Linnean Society of New South Wales 1 5(3): 302-444 (described as Ambassis elevatus, type locality Endeavour River, Queensland)

Rendahl, H. 1922. A contribution to the ichthyology of north-west Australia. Meddelelser fra det Zoologiske Museum. Kristiania 5: 163-197 figs 1-6 (described as Ambassis dalyensis, type locality Daly River, Northern Territory)

Whitley, G.P. 1953. Fishes collected by the Australian Museum Expedition, 1952. Records of the Australian Museum 23(3): 123-131, https://doi.org/10.3853/j.0067-1975.23.1953.626 (as Blandowskiella dalyensis)

Yoshigou, H. 2025. Morphological comparison within the glass perchlets genus Ambassis (Osteichthyes: Ovalentalia: Ambassidae), with reference to the comparison of some characters shared with other related genera. Miscellaneous reports of the Hiwa Museum for Natural History 66：1 -47.