© Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia Full citation Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia: Volume 1 - Bony and Cartilaginous Fishes. Report for the South Australian Working Group for Marine Species of Conservation Concern. J. Baker (consultant); Science and Conservation Division, and Coast and Marine Conservation branches of S.A. Department for Environment and Heritage (DEH); Marine and Coastal Community Network of S.A. (MCCN), and Threatened Species Network (TSN). Web version published by Reef Watch, South Australia.

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PETROMYZONTIDAE: LAMPREYS

© M. Hammer

Lampreys (Cephalaspidomorphi) and Hagfishes (Pteraspidomorphi) are two of the four surviving classes of “fish”, the other two classes being sharks and bony fish (Edgar, 2000). Both the lamprey and hagfish classes contain few living species, and the two groups are the most primitive extant vertebrates, with definite fossil records of lampreys dating back at least 280 million years (Hardisty, 1986, cited in Froese and Pauly, 2008), and hagfishes dating back 350 million years.

Petromyzontidae

The eel-like lampreys (family Petromyzontidae) are a primitive group of fish, whose members have a cartilaginous skeleton and a notochord; a scale-less body; seven small gill slits on either side of the head; a jawless mouth, in the form of a round suction disc, lined with small teeth; and a single nostril on top of the head. Lampreys also lack paired fins and anal fins. Their teeth occur on an oral disc and on the tongue (Glover, in Gomon et al., 1994; Froese and Pauly, 2008).
Lampreys are found mainly in the temperate zones of the world, and occur in marine, brackish and fresh waters. Most species of lamprey have both freshwater and marine life stages, although several species have become land-locked and have adapted to an entirely freshwater existence (Glover, in Gomon et al., 1994). The freshwater species are non-parasitic (Froese and Pauly, 2008).
Adult lampreys feed by latching onto fish and sucking or rasping away the blood and flesh (Water and Rivers Commission of Western Australia, 2000b).
Lamprey reproduction is characterised by the presence of separate sexes, with the females producing numerous (thousands) of small non-yolky eggs, usually buried in spawning redds that are excavated in clean, hard bottoms. The parents die after spawning, and there is a radical metamorphosis of the ammocoete larvae in fresh water (Hardisty, 1986, cited in Froese and Pauly, 2008). Further details are provided in the section below, on southern Australian lampreys of conservation concern.
Lamprey ammocoetes and adults are used as bait in some parts of the world, and a number of species are also used as food (Hardisty, 1986, cited in Froese and Pauly, 2008).
Globally, 42 named species from 9 genera are currently included in the family (Froese and Pauly 2008). Some authors put the Southern Hemisphere lampreys into the separate families Mordaciidae and Geotriidae. Two genera of lampreys have been recorded in Australia, and both occur in southern waters (Glover, in Gomon et al., 1994).

Associated taxa

Pouched Lamprey	Geotria australis Gray, 1851
Short-headed Lamprey	Mordacia mordax (Richardson, 1846)