PORT PHILLIP BAY


Shorthead Lamprey 

Mordacia mordax (Richardson, 1846)

View scientific description and taxonomy

Scientific Details

Additional information in:
Gomon. M.F., Bray, D.J. & Kuiter, R.H. (eds) (2008) Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Order level detail.
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 subfamilies live in Australian waters: the Geotriinae or Pouched Lampreys, and the Mordaciinae 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 and 7 pairs of pore-like gill openings pores along the sides. They lack scales and paired fins.

Family level detail.
Primitive eel-like fishes with eyes dorsolaterally on head and a jawless mouth in the form of an oral sucking disc with sharp 'horny' teeth. Sides of head with 7 pore-like gill openings, a single median nostril on top of the head and two small dorsal fins far back on the body.

Taxonomy

Phylum:
Chordata
Subphylum:
Craniata
Superclass:
Petromyzontomorphi
Class:
Petromyzontida
Order:
Petromyzontiformes
Family:
Mordaciidae
Genus:
Mordacia
Species:
mordax

General Description

Long, slender eel-like fishes with two dorsal fins near the tail, 7 pairs of pore-like gill openings, a single median nostril, an oral disc and a prominent hood-like sructure overhanging the mouth. 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. To 56 cm.

Biology

Shorthead Lampreys inhabit shallow coastal and inland waters that are connected to the sea. Following metamorphosis, they migrate downstream and spend most of their adult lives at sea, before returning to freshwater streams to breed.

Distribution guide

South-eastern Australia.

Species Group

Fishes › Lampreys

Depth

Shore (0-1 m)
Shallow (1-30 m)
Deep ( > 30 m)

Water Column

On or near sea floor

Max Size

56 cm

Commercial Species

No

Global Dispersal

Native to Australia

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Bray, D.J.

Di Bray is a Senior Collection Manager of ichthyology at Museum Victoria.

Author

article author Gomon, M.F.

Dr. Martin Gomon is a Senior Curator of ichthyology at Museum Victoria.

citation

Cite this page as:
Bray, D.J. & Gomon, M.F., 2011, Shorthead Lamprey, Mordacia mordax, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 25 Feb 2025, http://136.154.202.208:8098/species/6585

Text: creative commons cc by licence