Shorthead Lamprey, Mordacia mordax (Richardson 1846)
Shorthead Lamprey, Mordacia mordax. Source: Rudie Kuiter / Aquatic Photographics. License: All rights reserved
Primitive jawless fishes with naked eel-like bodies, two low dorsal fins far back on the body and 7 pairs of enlarged pore-like gill openings. They have eyes on top of their and prominent hood-like sructure overhanging the mouth.
The oral sucking disc is armed with tooth plates arranged in a radial pattern. Their ammocoete larvae are worm-like and lack eyes and teeth.
Shorthead Lampreys have an anadramous life cycle, spending parts of their life cycle in freshwater and in the sea. The adults spawn in freshwater, and their ammocoete larvae spend several years living in freshwater streams.
Following metamorphosis, they migrate downstream and spend most of their adult lives at sea, before returning to freshwater streams to breed.
Shorthead Lamprey, Mordacia mordax (Richardson 1846)
More Info
|
Distribution |
Occurs in freshwater and coastal marine environments of south-eastern Australia, from the river systems and offshore waters near Adelaide, South Australia, throughout Tasmania and Victoria, and north along the New South Wales to near Sydney. The range extends moderate distances upstream in coastal rivers. The life cycle is anadramous, where the post-larvae and premature adults are marine, and the other stages occur in freshwaters. |
|
Features |
Body eel-like, lacking scales; gill openings are 7 enlarged pores; mouth modified into an oral disc with sharp horny teeth in 2 large plates each with 3 large teeth and a series of smaller plates radiating outwards around mouth with smaller teeth; rim of sucking disc without fleshy papillae; single median nostril on top of head; eyes dorsolaterally on head; ammocoetes (<12cm) lack eyes and have a single undivided dorsal fin. The two dorsal fins are set well back near the tail; first with short base, 2nd longer, (2 or more times length of 1st); anus below and behind midpoint of 2nd dorsal fin, usually below posterior 3rd of fin; lacking pectoral, ventral and anal fins. |
|
Size |
To 56 cm TL, although usually between 35-40 cm. Most adults are 300-440 mm when they migrate back to freshwater. Ammocoete larvae begin metamorphosis between 100 and 140 mm. |
|
Colour |
The early post-larvae are greyish-brown above and silvery below. Young adults are bright blue above, with silvery sides and ventral surface. Mature adults are blue-grey above, silvery below and have orange teeth when in freshwater. |
|
Feeding |
The ammocoete larvae filter feed on plankton, detritus and microalgae. The adults are parasitic on other fishes and attach to their host with the suctorial disc. They use their toothy tongue to rasp flesh and feed on the body fluids and muscle of the host. The adults cease to feed during their migration back to freshwater rivers to spawn, surviving on stored fats and body tissues. |
|
Biology |
Adults return to freshwater rivers where they usually spawn in small, shallow creeks and streams with gravelly substrates. The female prepares a small depression or nest in the substrate and attaches herself to a rock with the oral disc. The male attaches to the female with his oral disc and wraps around her to squeeze out eggs before releasing sperm. Adults die shortly after spawning. Newly hatched larvae (ammocoetes) drift downstream into slow-flowing areas and burrow into muddy substrates. The larvae grow to a maxixum length of 17 cm and metamorphose after 3 to 4 years. The young migrate downstream during late winter and spring, and spend most of their adult lives in estuaries or at sea. |
|
Fisheries |
In the past, small numbers of Shorthead lampreys caught in the Yarra River were sold commercially. |
|
Conservation |
Not evaluated. |
|
Similar Species |
Although the two species of Mordacia are very similar, Nonparasitic Lampreys (Mordacia praecox) lack radial tooth plates, are smaller in size and spend their entire lives in freshwater streams of southeastern Australia. |
|
Etymology |
The specific name is from the Latin mordax (= biting, snappish), possibly in reference to the parasitic behavior and/or the whorl of serrated, cutting teeth of this species. |
|
Species Citation |
Petromyzon mordax Richardson 1846, Zool. Voy. Erebus and Terror 2: 62, pl. 38(3-6). Type locality: Tasmania. |
|
Author |
Gomon, M.F. & Bray, D.J. 2023 |
|
Resources |
Shorthead Lamprey, Mordacia mordax (Richardson 1846)
References
Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.
Cadwallader, P.L. & Backhouse, G.N. 1983. A Guide to the Freshwater Fish of Victoria. Melbourne : F.D. Atkinson Government Printer 249 pp. figs.
Chilcott, S. J. & Humphries, P. 1996. Freshwater fish of northeast Tasmania with notes on the dwarf galaxias. Records of the Queen Victoria Museum, Launceston 103: 145-149
Collin, S.P. 2009. Early evolution of vertebrate photoreception: lessons from lampreys and lungfishes. Integr. Zool. 4(1): 87-98.
Collin, S.P., N.S. Hart, K.M. Wallace, J. Shand & I.C. Potter. 2004. Vision in the southern hemisphere lamprey Mordacia mordax: Spatial distribution, spectral absorption characteristics, and optical sensitivity of a single class of retinal photoreceptor. Visual Neuroscience 21: 765-773. https://doi.oeg/10.1017/S0952523804215103
Collin, S.P. & Potter, I.C. 2000. The ocular morphology of the southern hemisphere lamprey Mordacia mordax Richardson with special reference to a single class of photoreceptor and a retinal tapetum. Brain, Behavior and Evolution 55(3):120-38. https://doi.org/10.1159/000006647
Collin, H.B., Ratcliffe, J. & Collin, S.P. 2023. The functional anatomy of the cornea of the Shorthead lamprey, Mordacia mordax (Mordaciidae, Agnatha): A comparison between downstream and upstream migrants. Journal of Morphology 284: e21552. https://doi.org/10.1002/jmor.21552
Conlon, J.M., Wang, Y. & Potter, I.C. 2001. The structure of Mordacia mordax insulin supports the monophyly of the Petromyzontiformes and an ancient divergence of Mordaciidae and Geotriidae. Comparative Biochemistry and Physiology, Part B 129(1): 65-71.
Gill, H.S., G.B. Renaud, F. Chapleau, R.L. Mayden & I.C. Potter. 2003. Phylogeny of living parasitic lampreys (Petromyzontiformes) based on morphological data. Copeia. 2003(4): 687-703.
Gilligan, D. 2019. Mordacia mordax. The IUCN Red List of Threatened Species 2019: e.T122898736A123382016. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T122898736A123382016.en. Accessed on 15 November 2023.
Glover, C.J.M. 1994. Families Petromyzontidae, Myxinidae, Hexanchidae, Heterodontidae. pp. 82-90 figs 17-26 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H. (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs.
Gomon, M.F. 2008. Families Geotriidae and Mordaciidae. pp. 28-29 in Gomon, M.F., Bray, D.J. & Kuiter, R.H. (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.
Hammer, M.P. & K.F. Walker. 2004. A catalogue of South Australian freshwater fishes, including new records, range extensions and translocations. Transactions Royal Society of South Australia 128(2): 85-97.
Hardisty, M.W. & Potter, I.C. (eds). 1971. The Biology of Lampreys. London : Academic Press, 2 vols.
Hardisty, M.W., Potter, I.C. & Koehn, J.D. 1992. Gonadogenesis and sex differentiation in the southern hemisphere lamprey Mordacia mordax. Journal of Zoology 226: 491-516. https://doi.org/10.1111/j.1469-7998.1992.tb07494.x
Hughes, R.L. & Potter, I.C. 1969. Studies on gametogenesis and fecundity in the lampreys Mordacia praecox and M. mordax (Petromyzonidae). Australian Journal of Zoology 17: 447-464.
Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs.
McDowall, R.M. (ed.) 1980. Freshwater Fishes of South-eastern Australia. Sydney : A.H. & A.W. Reed 208 pp., figs, 32 pls.
McDowall, R.M. (ed.) 1996. Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 247 pp.
Miller, A.K., Baker, C., Kitson, J.C., et al. 2021. The Southern Hemisphere lampreys (Geotriidae and Mordaciidae). Reviews of Fish Biology and Fisheries 31: 201-232. https://doi.org/10.1007/s11160-021-09639-x
Neira, F.J., Bradley, J.S., Potter, I.C. & Hilliard, R.W. 1988. Morphological variation among widely dispersed larval populations of anadromous southern hemisphere lampreys (Geotriidae and Mordaciidae). Zoological Journal of the Linnean Society 92(4): 383-408.
Potter, I.C. 1968. Mordacia praecox, n. sp., a nonparasitic lamprey (Petromyzontidae), from New South Wales, Australia. Proceedings of the Linnean Society of New South Wales 92(3): 254-261 figs 1-3 pl. 14
Potter, I.C. 1970. The life cycles and ecology of Australian lampreys of the genus Mordacia. Journal of Zoology 161: 487–511 https://doi.org/10.1111/j.1469-7998.1970.tb02051.x
Potter, I.C., Lanzing, W.J.R. & Strahan, R. 1968. Morphometric and meristic studies on populations of Australian lampreys of the genus Mordacia. Journal of the Linnean Society of London, Zoology 47: 533-546
Potter, I.C. & Strahan, R. 1968. The taxonomy of lampreys Geotria and Mordacia and their distribution in Australia. Proceedings of the Linnean Society of London 179(2): 229-240 figs 1-2
Raadik, T.A. 1992. Distribution of freshwater fishes in east Gippsland, Victoria, 1967–1991. Proceedings of the Royal Society of Victoria 104: 1-22.
Renaud, C.B. 2011. Lampreys of the World. An Annotated and Illustrated Catalogue of Lamprey Species Known to Date. FAO Species Catalogue for Fisheries Purposes No. 5. Rome : FAO 116 pp.
Richardson, J. 1846. Ichthyology. pp. 53-74 pls 31-41, 43-44 & 53 (part) in Richardson, J. & Gray, J.E. (eds). The Zoology of the Voyage of H.M.S. Erebus and Terror under the Command of Captain Sir James Clark Ross, R.N., F.R.S., during the years 1839–43. London : E.W. Janson Vol. 2 139 pp. See ref online
Scott, T.D., Glover, C.J.M. & Southcott, R.V. 1974. The Marine and Freshwater Fishes of South Australia. Adelaide : Government Printer 392 pp. figs.
Strahan, R. 1960. A comparison of the ammocoete and macrophthalmia stages of Mordacia mordax and Geotria australis (Petromyzonidae). Pacific Science 14: 416-420.
Waite, E.R. 1921. Illustrated catalogue of the fishes of South Australia. Records of the South Australian Museum (Adelaide) 2(1): 1-208 293 figs pl. 1 (as Caragola mordax)
Warrington, R.E., Hart, N.S., Potter, I.C., Collin, S.P. & Hemmi, J.M. 2017. Retinal temporal resolution and contrast sensitivity in the parasitic lamprey Mordacia mordax and its non-parasitic derivative Mordacia praecox. Journal of Experimental Biology 220(Pt 7): 1245-1255. https://doi.org/10.1242/jeb.150383
Whitley, G.P. 1940. The Fishes of Australia. Part 1. The sharks, rays, devil-fish, and other primitive fishes of Australia and New Zealand. Sydney : Roy. Zool. Soc. N.S.W. 280 pp. 303 figs.
Yamazaki, Y. & Goto, A. 2000. Present status and perspectives on the phylogenetic systematics and speciation of lampreys. Japanese Journal of Ichthyology 47(1): 1-28.
