The Saddled Galaxias (Galaxias tanycephalus) is a medium sized native freshwater fish growing to a maximum length of 150 mm. The species is found only in two lakes in the Central Highlands of Tasmania; it is abundant in Woods Lake and less common in Arthurs Lake. Both lakes have Brown Trout (Salmo trutta) populations, and nearby Great Lake also contains Rainbow Trout (Oncorhynchus mykiss), and trout are known to predate on the Saddled Galaxias. However, the Saddled Galaxias has coexisted with trout for over a century and currently is not thought to be threatened by trout under present natural recruitment levels. Reduced availability of important littoral habitats (e.g. rocky shore and macrophyte beds) via low water levels, associated with hydro-electric power generation and irrigation supplies, are thought to be a significant threat to this species. Additional potential threats to the species include introduction of other exotic fish such as Redfin Perch (Perca fluviatilis), and deterioration in water quality. The principal management objectives for the species are to protect the two populations, ensure suitable water level regimes are preserved, and to investigate the possibility for translocations to establish a third 'refuge' population of the species.
- Important: Is this species in your area? Do you need a permit? Ensure you’ve covered all the issues by checking the Planning Ahead page.
- Important: Different threatened species may have different requirements. For any activity you are considering, read the Activity Advice pages for background information and important advice about managing around the needs of multiple threatened species.
- ‘Habitat’ refers to both known habitat for the species (i.e. in or near habitat where the species has been recorded) and potential habitat (i.e. areas of habitat with appropriate characteristics for the species and within the species potential range which have not yet been surveyed).
- If in doubt about whether a site represents potential habitat for this species, contact the Threatened Species Section for further advice.
- The known range of the Saddled Galaxias includes Woods Lake and Arthurs Lake in Tasmania's Central Highlands (see distribution map, above). The potential range for the Saddled Galaxias may extend into nearby waterways that are connected to Woods Lake and Arthurs Lake, including Great Lake and the upper Lake River.
- Habitat for the Saddled Galaxias includes the following elements: mainly lacustrine (lake-dwelling) with only a few individuals found in the lower reaches of in-flow streams; within the lakes adults occur in areas where rocks and aquatic vegetation provide shelter; juveniles occur in the lake water column until around 4-6 months of age.
What to avoid
- Spread of exotic fish (European Carp Cyprinus carpio, and Redfin Perch) into the species' habitat
- Changes to water levels and water quality due to draw-downs for hydroelectric power generation and irrigation
- The principal method for surveying lake-dwelling fish including the Saddled Galaxias is fyke netting. Electro-fishing is also an effective method. This technique requires specialist equipment and expertise, where an electric current is passed through the lake or stream water to stun any fish present. When performed correctly, the sampled fish are generally unharmed. This technique should only be performed by trained specialists with the appropriate permit.
Helping the species
- Consider the needs of the whole habitat. Preserving a threatened species' habitat is the best way to manage both the species and the environment in which it lives.
- Remember that introducing exotic fish such as European Carp or Redfin Perch to waters where they are currently absent can have potentially devastating impacts on native fish species. Avoid any activities which could inadvertently lead to exotic fish introductions, and inform others about the potential risks of introducing exotic fish.
Cutting or clearing trees or vegetation
- Removing lakeside and streamside vegetation can have profound effects on water quality.
- To avoid impacting on known populations – do not remove trees or other lakeside and streamside vegetation around and upstream of known populations.
- To avoid changes to hydrology, including increased sedimentation from ash or soil washed from the surrounding land – avoid uncontrolled burning of lakeside and streamside vegetation in the vicinity of populations.
Changing water flow / quality
- Both Woods Lake and Arthurs Lake are subject to manipulation of water levels for hydro power generation and irrigation. Water drawdowns can cause high water turbidities and nutrient levels, as well as reduce Saddled Galaxias habitat, particularly in shallow water where important habitats (e.g. rocky shores and macrophyte beds) are vulnerable to dewatering.
- To avoid impacts on water quality and available habitat - manage lake draw-downs so as to minimise impacts on the Saddled Galaxias.
Use of chemicals
- To avoid impacts on the survival and breeding of populations – do not use herbicides and pesticides in the vicinity of known populations where this could lead to input of chemicals toxic to the species into the waterway.
- The Saddled Galaxias is vulnerable to the introduction of other exotic fish species such as European Carp and Redfin Perch, and to increases in abundance of trout populations.
- To avoid introduction of exotic fish to waters inhabited by the Saddled Galaxias – do not carry out any activities, including active stocking, which could lead to the establishment of introduced fish in waterways supporting the Saddled Galaxias.
- This species is highly vulnerable to the introduction of European Carp and Redfin Perch.
- To avoid the risk posed by introductions of other exotic fish species – do not carry out any activities which could enable these fish to enter and establish in streams and lakes supporting the Saddled Galaxias.
Check also for listing statement or notesheet pdf above (below the species image).