In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.
|EPBC Act Listing Status||Listed as Vulnerable|
|Listing and Conservation Advices||
Commonwealth Conservation Advice on Ophisternon candidum (Blind Cave Eel) (Threatened Species Scientific Committee (TSSC), 2008agk) [Conservation Advice].
|Recovery Plan Decision||
Recovery Plan not required, included on the Not Commenced List (1/11/2009).
|Adopted/Made Recovery Plans|
|Policy Statements and Guidelines||
Survey guidelines for Australia's threatened fish. EPBC Act survey guidelines 6.4
(Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011i) [Admin Guideline].
Federal Register of
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument].
|State Listing Status||
|Scientific name||Ophisternon candidum |
|Species author||Mees, 1962|
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
Scientific name: Ophisternon candidum
Common name: Blind Cave Eel
The Blind Cave Eel is a pure white fish growing to 40 cm, with an eel-like body, no eyes, and a thin rayless membrane around the tip of the tail (Allen 1989a). The Blind Cave Eel is the world's longest cavefish and one of only two vertebrate animals known from Australia that are restricted to subterranean waters (Humphreys 2001).
The Blind Cave Eel is known only from subterranean waters of the Cape Range Peninsula and incidentally in Bungaroo Creek (near Pannawonica, 100 km south of Karratha), north-west WA (Humphreys & Feinberg 1995; WA OEPA 2012). The species possibly has uniform distribution under the narrow peninsula, but sampling has been restricted to wells and natural caves (Allen 2000 pers. comm.). This species has been recorded from at least 11 localities on the North West Cape (Humphreys 1999) and one site 100 km south of Karratha (WA OEPA 2012), however, not all localities are extant and some localities are inaccessible (i.e. caves/wells have been filled in) (Humphreys 1999). Records have been limited to the upper part of the anchialine system (TSSC 2008agk). At most three individuals are known from any given site (TSSC 2008agk).
Specimens were collected from 1959 to 1963 at the following localities on the North West Cape of WA (Australian Fish Collection Records):
- Yardie Creek Homestead/Tantabiddi Well (21°56'S, 113°58'E)
- Unnamed locality (21°47'S, 114°10'E).
Specimens were collected from 1969 to 1994 at the following localities (Humphreys & Adams 1991; Humphreys 1994, 1999):
- Cave on east side of North West Cape, south of Exmouth (cave not seen for many years, last record 1969)
- Milyering Well - recorded in 1993 (approximately 22°01'S, 113°56'E)
- Former pastoral well north of Tantabiddi Well - recorded in 1993 (unnamed, approximately 21°55'S, 113°59'E)
- Tantabiddi Well - recorded in 1993 (21°56'S, 113°58'E)
- Kubura Well - recorded in 1993 (on east side of North West Cape, north of Exmouth, 21°56'S, 114°08'E)
- Unnamed cave in former gravel pit on east side of North West Cape, south of Exmouth. Recorded in 1990 (approximately 21°58'S, 114°08'E)
- Pilgramunna Well on west side of North West Cape - last record 1969 (22°12'S, 113°52'E)
- Mowbowra Well on east side of North West Cape on Mowbowra Creek, south of Exmouth. Not recorded since 1991 and the well has subsequently been filled in (22°00'S, 114°07'E)
- Tidal cave (Crown land) on west side of North West Cape, north of Five Mile Well. Last record 1993 (approximately 21°50'S, 114°05'E)
- Cave just east of locality 9. Last record 1993 (approximately 21°50'S, 114°05'E).
Specimens were sighted in a well south of Yardie Creek (location unknown) in 1977, but no specimens were collected (Allen 1982). In 2009, a specimen was incidentally recorded in Bungaroo Creek (near Pannawonica, 100 km south of Karratha) (WA OEPA 2012).
The few specimens collected suggest that it is rare (Allen 1982; Mees 1962), but this may be due in part to the limited collecting and the inaccessibility of its habitat (Allen 1982).
The Blind Cave Eel inhabits subterranean caves, fissures (Allen 1982) and wells (Humphreys 1999) and is one of only two vertebrate animals known from Australasia that are restricted to either caves or groundwater - the other is the Blind Gudgeon (Milyeringa veritas) (Humphreys & Blyth 1994). The Blind Cave Eel inhabits the surface of, and burrows into, the faecal ooze characteristic of crustacean-rich habitats (Humphreys & Feinberg 1995). The caves have a rich stygofaunal community that contains a number of eco-geographical relicts and phyletic relics with tethyan affinities (Allen 2000 pers. comm.).
The waters in the caves are markedly stratified, (Humphreys 1999a; Seymour et al. 2007), ranging from freshwater at the surface to full seawater salinity at depth. While affected by marine tides, the waters lack surface connection to the sea (termed anchialine ecosystems: Humphreys 1999a). The fish traverse this range of salinity levels that occur in these systems (Humphreys et al. 2006).
The subterranean habit of the Blind Cave Eel restricts observation and hence very little is known about the reproductive biology (Humphreys & Feinberg 1995).
The Blind Cave Eel feeds opportunistically on minute (less than 2 mm total length) Stygiocaris shrimps and the shrimp Halosbaena tulki at Tantabiddy Well. Analyses of stomach contents demonstrate that the larvae of terrestrial insects (dragonflies and flies) and juveniles or adults of other arthropods (slaters) also make up the eel's diet. All the prey items identified are bottom dwellers or sink to the bottom when they fall into the water (Humphreys & Feinberg 1995).
The Blind Cave Eel inhabits the surface of and burrows into the flocculent faecal ooze characteristic of crustacean-rich cave habitats (Humphreys 2001), so it is more likely to be found near the bottom of the water column. Cawthorne (1963) observed a Blind Cave Eel in deeper water, but failed to catch it. Owing to its length and bottom living habit, the Blind Cave Eel is unlikely to be taken by trapping or netting and all records have been derived from sites large enough for people to access groundwater, such as caves and pastoral wells (TSSC 2008agk).
Most of the caves in the Cape Range are vertical and require specialised roping skills to enable entry and exit. The caves are mostly dry, but many are unstable and contain dangerous concentrations of carbon dioxide (Humphreys & Blyth 1994). Caving experts should be used in surveys if descending into the caves is necessary, and especially if such work is to be conducted at night (DSEWPaC 2011i).
Most appropriate methods
The information available suggests that successful detection methods include visual observations during the day (either by looking down into the wells and sinkholes or snorkelling) and night observation with headlamps (from above the wells or holes). The Blind Cave Eel is rarely seen and difficult to observe without extensive effort (DSEWPaC 2011i).
Moyle and Cech (1982 in Humphries & Feinberg 1995) noted that members of the Synbranchidae family (to which the Blind Cave Eel belongs) are nocturnal predators. However, detection methods without direct sunlight prior to capture have never been successful for the species (Humphreys 2001).
The remote locations of these cave fish and their subterranean habitat restricts observation (Humphreys 2001). However, despite the general remoteness of the area, the populations are at sufficiently accessible locations to facilitate sampling (Humphreys 2001). The rarity of the Blind Cave Eel can result in no sightings after several hours in most areas (DSEWPaC 2011i).
The main identified threats to the Blind Cave Eel include sedimentation from mining (quarrying of limestone) and construction (roads and urban development at Exmouth); canal development; water abstraction; point source pollution from sewage, landfill and rubbish dumping; and diffuse pollution from urban development (Humphreys 2001). Open sites may serve to permit the invasion by feral fish, especially guppies (Poecilia sp.) (Plath et al. 2007). As the major food source of the Blind Cave Eel (i.e. shrimps) is also endemic, threats to the shrimps will threaten the Blind Cave Eel (Humphreys & Feinberg 1995).
A number of access sites on the Cape Range Peninsula have been lost over time from the combined effects of infilling, drying and siltation. A number of other sites are close to planned developments, near urban areas or are in unmanaged military areas (Humphreys 1999; Wager & Jackson 1993). All populations of Blind Cave Eels on the Cape Range Peninsula need protection from any form of habitat degradation to preserve their limited genetic diversity (Humphreys 1999).
The Commonwealth Conservation Advice on the Blind Cave Eel identifies the following priority actions for recovery (TSSC 2008agk):
- Determine the pattern of genetic variation within the range of the Blind Cave Eel.
- More precisely assess population size distribution, ecological requirements and the relative impacts of threatening processes.
- Monitor known populations to identify key threats.
- Monitor the progress of recovery, including the effectiveness of management actions and the need to adapt them if necessary.
- Manage any changes to hydrology that may result in changes to the water table levels, increased run-off, sedimentation or pollution.
- Manage any disruptions to water flows.
- Minimise adverse impacts from land use within the range of the groundwater ecosystem.
- Prevent point source pollution of groundwater by petrochemicals, leachates and sewage.
- Ensure sediments do not enter groundwater ecosystem.
- Investigate formal conservation agreements such as the use of covenants, conservation agreements or inclusion of habitat in reserve tenure.
- Manage known sites to exclude/control introduced fish species, and the associated introduction of disease/parasites.
- Raise awareness of the species within the local community.
WA Speleological Group Inc received $22 260 of funding through the Threatened Species Network Community Grants in 2005-06, part of which was for protection of this species from potential disease impacts and habitat competition from introduced exotic guppies in caves of the North West Karst system.
The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.
|Threat Class||Threatening Species||References|
|Energy Production and Mining:Mining and Quarrying:Habitat destruction, disturbance and/or modification due to mining activities||Commonwealth Conservation Advice on Ophisternon candidum (Blind Cave Eel) (Threatened Species Scientific Committee (TSSC), 2008agk) [Conservation Advice].|
|Energy Production and Mining:Mining and Quarrying:Habitat modification through open cut mining/quarrying activities||Subterranean Secrets. Landscope - W.A's Conservation, Forests and Wildlife Magazine. 9, No. 3:22-27. (Humphreys, B. & J. Blyth, 1994) [Journal].|
|Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition, predation and/or habitat degradation by fish||
The distribution of Australian cave fishes. Records of the Western Australian Museum. 19:469-472. (Humphreys, W.F., 1999) [Journal].
Commonwealth Conservation Advice on Ophisternon candidum (Blind Cave Eel) (Threatened Species Scientific Committee (TSSC), 2008agk) [Conservation Advice].
|Natural System Modifications:Dams and Water Management/Use:Changes to habitat hydrology||Commonwealth Conservation Advice on Ophisternon candidum (Blind Cave Eel) (Threatened Species Scientific Committee (TSSC), 2008agk) [Conservation Advice].|
|Pollution:Garbage and Solid Waste:Dumping of household and industrial waste||Commonwealth Conservation Advice on Ophisternon candidum (Blind Cave Eel) (Threatened Species Scientific Committee (TSSC), 2008agk) [Conservation Advice].|
|Pollution:Household Sewage and Urban Waste Water:Pollution (chemicals, sewage) due to urban and agricultural run-off|
|Pollution:Pollution:Changes to water and sediment flows leading to erosion, siltation and pollution|
|Pollution:Pollution:Pollution due to oil spills and other chemical pollutants|
|Residential and Commercial Development:Housing and Urban Areas:Habitat loss, modification and fragmentation due to urban development||The Action Plan For Australian Freshwater Fishes (Wager, R. & P. Jackson, 1993) [Cwlth Action Plan].|
|Residential and Commercial Development:Residential and Commercial Development:Habitat modification (clearance and degradation) due to urban development|
Allen, G.R. (1982). A Field Guide to Inland Fishes of Western Australia. Perth, Western Australia: University of Western Australia Press.
Allen, G.R. (1989a). Freshwater Fishes of Australia. Brookvale, NSW: T.F.H. Publications.
Allen, G.R. (2000). Personal communication.
Australian Fish Collection Records (undated). Collation of records from Australian Fish Collections.
Cawthorn, P. (1963). Discovery of subterranean freshwater fauna on the eastern side of North West Cape. The Western Australian Naturalist. 8(6):129-132.
Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2011i). Survey guidelines for Australia's threatened fish. EPBC Act survey guidelines 6.4 . [Online]. EPBC Act policy statement. Canberra, ACT: DSEWPAC. Available from: http://www.environment.gov.au/epbc/publications/threatened-fish.html.
Humphreys, B. & J. Blyth (1994). Subterranean Secrets. Landscope - W.A's Conservation, Forests and Wildlife Magazine. 9, No. 3:22-27.
Humphreys, W.F. (1994). The subterranean fauna of the Cape Range coastal plain, northwestern Australia. Page(s) 202.
Humphreys, W.F. (1999). The distribution of Australian cave fishes. Records of the Western Australian Museum. 19:469-472.
Humphreys, W.F. (1999a). Physico-chemical profile and energy fixation in Bundera Sinkhole, an anchialine remiped habitat in north-western Australia. Journal of the Royal Society of Western Australia. 82:89-98.
Humphreys, W.F. (2001). Milyeringa veritas Whitley 1945 (Eleotridae), a remarkably versatile cave fish from the arid tropics of northwestern Australia. Environmental Biology of Fishes. 62:297-313.
Humphreys, W.F. & M. Adams (1991). The subterranean aquatic fauna of the North West Cape peninsula, Western Australia. Records of the Western Australian Museum. 15, Part 2:383-411.
Humphreys, W.F. & M.N. Feinberg (1995). Food of the blind cave fishes of northwestern Australia. Records of the Western Australian Museum. 17:29-33.
Humphreys, W.F., J.C. Shiao, Y. Iizuka & W.-N. Wann-NianTzeng (2006). Can otolith microchemistry reveal whether the blind cave gudgeon, Milyeringa veritas (Eleotridae), is diadromous within a subterranean estuary?. Environmental Biology of Fishes. 75:439-453.
Mees, G.F. (1962). The subterranean freshwater fauna of Yardie Creek Station, North West Cape, Western Australia. Journal of the Royal Society of Western Australia. 45, Part 1:24-32.
Plath, M., J.S. Hauswaldt, K. Moll, M. Tobler, F.J. Garciadeleon, I. Schlupp & R. Tiedemann (2007). Local adaptation and pronounced genetic differentiation in an extremophile fish, Poecilia Mexicana, inhabiting a Mexican cave with toxic hydrogen sulphide. Molecular Ecology. 16:967-976.
Seymour, J.R., W.F. Humphreys & J.G. Mitchell (2007). Stratification of the microbial community inhabiting an anchialine sinkhole. Aquatic Microbial Ecology. 50:11-24.
Threatened Species Scientific Committee (TSSC) (2008agk). Commonwealth Conservation Advice on Ophisternon candidum (Blind Cave Eel). [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/66678-conservation-advice.pdf.
Wager, R. & P. Jackson (1993). The Action Plan For Australian Freshwater Fishes. Canberra, ACT: Australian Nature Conservation Agency.
Western Australia Office of the Environmental Protection Authority (WA OEPA) (2012). A review of subterranean fauna assessment in Western Australia. Perth: Environmental Protection Authority.
This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.
Citation: Department of the Environment (2014). Ophisternon candidum in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sun, 9 Mar 2014 23:46:36 +1100.