FRESHWATER FISH Mordacia mordax Short-headed Lamprey AUS SA AMLR Endemism Act as part of the threatened species status review in 2003.2 - - V - Description Eel like fish reaching 50 cm, adults have a unique jawless, suction cap like mouth (oral disk). Distinguished easily from other freshwater fishes by a series of circular openings on the head (gills), the oral disk, and two distinct dorsal fins (eels have a long singular fin). Similar in appearance to Pouched Lamprey (often confused) but have eyes positioned to the top of the body (dorsally) and ridged teeth on the outer oral disk. Short- headed Lamprey also generally darker blue in colour and adults returning to freshwater are smaller. The worm-like juveniles (ammocetes) can be distinguished by the alignment of the cloaca (akin to an anus) with the middle of the dorsal fin.4 Distribution and Population Migratory species, occurring through South-eastern Australia from Shoalhaven River, NSW to Gulf of St Vincent, SA. Within the AMLR the species is only recorded in the Torrens River Basin, within the South Australian Gulf Drainage Division.3 Most likely occurs within the Murray- Darling Drainage Division within the AMLR, however there are currently no records (M. Hammer pers comm.). Current distribution and abundance largely unknown. Opportunistic records have diminished since the 1970s.4 SARDI recently caught Short-headed Lampreys at the mouth of the Torrens, prior to which there were no observations from the Torrens River since the 1950s Photos: © Michael Hammer (M. Hammer pers. comm.). Conservation Significance Due to the unusual appearance of lampreys there is a In SA, the AMLR distribution is disjunct from the reasonable level of opportunistic historic records held remaining extant distribution. Within the AMLR the at the SA Museum (comparative to other species), with species’ relative area of occupancy is classified as reasonably continuous records of Short-headed ‘Very Restricted’.3 Lamprey through to the 1970s from two main freshwater areas: (1) the Adelaide region including the Lampreys, along with hagfishes are the sole surviving Gawler Catchment, Port River estuary, Torrens River, representatives of the jawless vertebrates. They are Patawalonga Creek, Glenelg and Onkaparinga River, conveniently lumped in with the fishes due to the and (2) the River Murray system including the Coorong, aquatic/marine habit, but are a separate class of Salt Creek, Lake Alexandrina and the main channel animals (Agnantha). Within an evolutionary context, and occasional wetlands of the River Murray. birds are more closely related to reptiles than Reported to be very common in the River Torrens prior lampreys are to what are generally known as fish.5 to construction of the weir at the river mouth in the 4 1950s. Recommended for listing as Endangered under NPW Further information: Biodiversity Conservation Unit, Adelaide Region Phone: (61 8) 8336 0901 Fax: (61 8) 8336 0999 http://www.environment.sa.gov.au/ Department for Environment and Heritage FIS 90346 May 2008 Prepared as part of the Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia 2009 - 2014 Habitat necessarily represent the actual species’ distribution within the AMLR. Relatively common in streams, estuaries, and coastal seas of the south-east from the Hawkesbury River References (NSW) to Gawler River (SA), including TAS. Usually Note: In some cases original reference sources are not found close to the sea when in fresh water, but included in this list, however they can be obtained from the 1 reference from which the information has been sourced (the penetrates far inland in the River Murray (VIC). reference cited in superscript). Biology and Ecology 1 Allen, G. R., Midgley, S. H. and Allen, M. (2002). Field Guide Larval juvenile stage (ammocetes) lasts for several to the Freshwater Fishes of Australia. Western Australian years and precedes a radical metamorphosis. After Museum, Western Australia. about three years they swim downstream towards the sea where they parasitise marine fish using the 2 Department for Environment and Heritage (2003 ). Review abrasive sucking disk. The adult grows significantly of the Status of Threatened Species in South Australia. Proposed Schedules under the South Australian National Parks during this stage, then re-enters the river, migrating and Wildlife Act 1972 Discussion Paper. National Parks and 5 upstream, to spawn and die. Wildlife Council in partnership with the Department for Environment and Heritage. Aboriginal Significance Post-1983 records indicate the entire AMLR 3 Department for Environment and Heritage (2007). Adelaide distribution occurs in Kaurna Nation.3 and Mount Lofty Ranges Regional Recovery Pilot Project Database. Unpublished data extracted and edited from Threats BDBSA, SA Herbarium (July 2007) and other sources. The primary threat to lamprey species appears to be 4 Hammer, M., Wedderburn, S. and Van Weenen, J. (2007). major catchment modifications to hydrology, habitat Action Plan for South Australian Freshwater Fishes: 2007-2012 and fish movement. Reduced stream and River Draft. Native Fish Australia (SA) Inc., Adelaide. Murray flows (e.g. farm dams and water storages in the MLR) are affecting the amount of wetted habitat 5 Turner, M. S. (2001). Conserving Adelaide's Biodiversity: available, the quality of remaining habitat (e.g. less Resources. Urban Forest Biodiversity Program, Adelaide. dissolved oxygen and increased temperatures with decreased flows) and connectivity for migration.4 Additional current direct threats have been identified and rated for this species. Refer to the main plan accompanying these profiles. Regional Distribution Map based on filtered post-1983 records.3 Note, this map does not Further information: Biodiversity Conservation Unit, Adelaide Region Phone: (61 8) 8336 0901 Fax: (61 8) 8336 0999 http://www.environment.sa.gov.au/ Department for Environment and Heritage FIS 90346 May 2008 Prepared as part of the Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia 2009 - 2014 .