Common name: Lampreys


Lampreys are long, slender primitive jawless fishes with a cartilaginous skeleton, 7 pairs of gill slits, a single median nostril and an oral sucking disc with a tongue-like structure bearing many sharp rasping teeth or denticles. They have large eyes as adults and lack scales and paired fins. Their worm-like ammocoete larvae are filter-feeders and lack eyes and teeth. All species breed in freshwater, and some are anadromous, migrating to estuaries or the open ocean after they metamorphose. Some are parasitic on other fishes.

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Dianne J. Bray, Lampreys, MORDACIIDAE in Fishes of Australia, accessed 20 Apr 2024,

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Family Taxonomy

The family comprises 43 species in three subfamilies. Members of two subfamilies are found in Australian waters: the Geotriinae with a single species, Geotria australis and the Mordaciinae, with a single genus and two species, Mordacia mordax and M. praecox. Some authors have elevated the subfamilies to family status.

Family Distribution

Lampreys are antitropical in distribution, living in temperate rivers, streams and coastal areas of the northern hemisphere above 30°N and in the southern hemisphere in South Africa, South America, New Zealand and Australia below 30°S.

Family Size

To 90 cm.

Family Feeding

Although some adult lampreys are parasitic on other fishes, most species are non-parasitic. Parasitic lampreys feed on other fishes, attaching to the prey with their sucking disc and rasping away flesh with their toothy tongue.

Family Reproduction

Lampreys breed in freshwater streams, where the eggs hatch into filter feeding larvae known as ammocoetes. While some species spend their enitre lives in freshwater, many species are anadromous, migrating to the sea to mature before returning to spawn in freshwater rivers and streams.

Family Commercial

Although no fishery exists in Australia, lampreys have long been been consumed by humans. They are often considered a delicacy and their populations have been reduced by overfishing in many parts of the world. Lampreys are also sold as bait in some countries.

Family Conservation

The Non-parasitic Lamprey, Mordacia praecox, is listed as Vulnerable on the 2011 IUCN Red List of Threatened species.

Family Remarks

Lampreys have have a poor fossil record, possibly because of their cartilaginous skeletons. In 2006, the oldest known fossil lamprey dating back to the Devonian period, 360 million years ago, was found in South Africa.


Dianne J. Bray


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