Order PETROMYZONTIFORMES

Common name: Lampreys
Summary:

The order Petromyzontiformes is one of two groups of living jawless vertebrates. Lampreys are primitive eel-like cartilaginous fishes that inhabit cool-temperate marine and fresh waters. Two families live in Australian waters: the Geotriidae or Pouched Lampreys, and the Mordaciidae or Short-headed Lampreys.

Lampreys have a sucker-like oral disc or mouth, armed with rows of horny teeth, and a toothy rasping tongue. They have one or two dorsal fins, lack paired fins and their gill openings are a series of enlarged pores along the sides. They lack scales and paired fins.

Many lampreys are anadromous. The adults breed in freshwater rivers and streams and the larvae hatch and grow in freshwater. Juveniles migrate downstream to the sea to mature, and return as adults to spawn. Most lay their eggs in clear freshwater streams where the blind larvae (known as ammocoetes) remain buried in fine silt for several years, filter-feeding on plankton, detritus and microscopic algae. They usually metamorphose after about three years, developing eyes and teeth, and some species migrate to sea to mature.

Lampreys are specialised predators and the adults of some species are parasitic on other fishes. They use their sucking disc to attach to prey and rasp flesh with their toothy tongue to feed on tissue and body fluids. After several years, these lampreys cease feeding and return to freshwater rivers and streams to spawn, dying shortly after. Some land-locked populations are entirely freshwater.

The order comprises 40 species in three families, two of which are found in Australia. These ancient fishes have a fossil record dating back to the Devonian Period, 360 million years ago.

Author: Dianne J. Bray
Cite this page as:
Dianne J. Bray, Lampreys, PETROMYZONTIFORMES in Fishes of Australia, accessed 18 Apr 2024, https://fishesofaustralia.net.au/Home/order/35

Order References

Allen, G.R, S.H. Midgley & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum, Perth: 1-394.

Braun, C.B. 1996. The sensory biology of the living jawless fishes: a phylogenetic assessment. Brain Behav. Evol. 48: 262–276. 

Collin, S.P., Davies, W.L., Hart, N.S. and Hunt, D.M. 2009. The evolution of early vertebrate photoreceptors. Philosophical Transactions of The Royal Society B-Biological Sciences, 364 1531: 2925-2940. 

Davies, W.L., Collin, S.P. and Hunt, D.M. 2009. Adaptive Gene Loss Reflects Differences in the Visual Ecology of Basal Vertebrates. Molecular Biology and Evolution, 26 8: 1803-1809.

Gess, R.W., Coates, M.I. & Rubidge, B.S. 2006. A lamprey from the Devonian period of South Africa. Nature 443: 981–984.

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.

Hardesty, M.W. & I.C. Potter (eds). 1971. The Biology of Lampreys. Academic Press, London, 2 vols.

Nelson, J.S. 2006. Fishes of the World. John Wiley & Sons, New Jersey, 601 p.

Renaud, C.B. 2011. Lampreys of the world. An annotated and illustrated catalogue of lamprey species known to date. FAO Species Catalogue for Fishery Purposes. No. 5. Rome, FAO. 109 p. pdf