This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/7/2008 Approved Conservation Advice (s266B of the Environment Protection and Biodiversity Conservation Act 1999) Approved Conservation Advice for Lasionectes exleyi
This Conservation Advice has been developed based on the best available information at the time this conservation advice was approved.
Description Lasionectes exleyi, Family Speleonectidae, also known as Cape Range Remipede, is a free- swimming, cave-dwelling, remipede crustacean. It is characterised by a short head and long trunk composed of 21–24 segments, each with a pair of paddle-like swimming appendages. This species grows to 1–1.5 cm long (Yager & Humphreys, 1996).
Conservation Status Lasionectes exleyi is listed as vulnerable. This species is eligible for listing as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act) as, prior to the commencement of the EPBC Act, it was listed as vulnerable under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth). The species is also listed as rare or likely to become extinct under Schedule 1 of the Wildlife Conservation (Specially Protected Fauna) Notice 1998 (Western Australia).
Distribution and Habitat Lasionectes exleyi is known from a single anchialine (submerged) cave, Bundera Sinkhole, on the Cape Range peninsula, Western Australia. The Bundera Sinkhole is 1200 km north of Perth and 1.7 km inland from the Indian Ocean (Yager & Humphreys, 1996). The surface of the sinkhole is eutrophic, limiting the penetration of light into the water (Humphreys et al., 1999). The species is found at a depth of 30 m in a layer of saline water lying beneath a layer of brackish water at the surface (Black et al., 2001). Other fauna that occur in Bundera Sinkole include a blind fish, Milyeringa veritas, the hadziid amphipod Liagoceradocus branchialis, ostracods including Danielopolina kornickeri, an atyid shrimp (Page et al., 2008), and diverse copepods (Black et al., 2001). This species occurs within the Rangelands (Western Australia) Natural Resource Management Region. Bundera Sinkhole is in a hot and extremely dry region where the terrestrial vegetation is predominantly hummock grassland and sparse shrubs (Humphreys, 1999; Humphreys et al., 1999). Lasionectes exleyi is an ancient species and is the only remipede known in the Southern Hemisphere (Yager & Humphreys, 1996). The disjunct distribution of remipede species suggests that dispersal is limited. The distribution of this species is not known to overlap with any EPBC Act-listed threatened ecological communities.
Threats The main identified threats to Lasionectes exleyi include disruption to water stratification in Bundera Sinkhole; pollution; and a lack of formal protection of the cave and associated inflows. Although uncommon, diving threatens the sinkhole by disrupting the temperature and chemical stratification of the water profile (Humphreys et al., 1999). Development in the area that increases water inflow into Bundera Sinkhole threatens Lasionectes exleyi (Black et al., 2001). Bundera Sinkhole is accessible from a popular track and any pollution from visitors or toxic waste dumping (e.g. a car battery) would be catastrophic (Black et al., 2001).
Lasionectes exleyi Conservation Advice - Page 1 of 3 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/7/2008 The main potential threats to Lasionectes exleyi include contamination from nearby land uses; contamination from feral goats (Capra hircus); introduction of feral fish, especially the Guppy (Poecilia reticulata), and the disruption of groundwater flows into Bundera Sinkhole. Land use in the area is the overfly zone for the Learmonth Air Weapons Range but has largely uncontrolled access, and camping and waste disposal occurs on this coastal plain between occasional closures of the area for RAAF operational reasons. Use of the pool by feral goats and macropods may be the cause of high nutrient levels in the sinkhole. Guppies (Poecilia sp.) are tolerant to a wide range of salinities and may colonise caves with high H2S levels (Plath et al., 2007) and their introduction, or that of other predacious exotic fish, could eliminate Lasionectes exleyi. The broad chemocline between brackish and saline layers, initially considered stable, is dynamic, a site of exceptional microbiological diversity (Seymour et al., 2007) and where chemoautotrophic energy fixation may support the underlying stygal community of which L. exleyi is part (Humphreys, 1999).
Research Priorities Research priorities that would inform future regional and local priority actions include: • Design and implement a monitoring program (Clarke & Spier-Ashcroft, 2003). • Investigate the extent of occurrence of suitable habitat. • Investigate how the chemocline contributes to the energy supply and stability of the water body.
Regional and Local Priority Actions The following regional and local priority recovery and threat abatement actions can be done to support the recovery of Lasionectes exleyi. Habitat Loss, Disturbance and Modification • Monitor the progress of recovery, including the effectiveness of management actions and the need to adapt them if necessary. • Manage threats to surrounding areas of vegetation. • Control access routes to suitably constrain public access to Bundera Sinkhole. • Ensure chemicals used within the region do not have a significant adverse impact on L. exleyi. • Ensure road widening and maintenance activities (or other infrastructure or development activities) do not adversely impact on the known population. • Manage any changes to hydrology that may result in changes to the water table levels, increased run-off, sedimentation or pollution (Clarke & Spier-Ashcroft, 2003). • Manage any disruptions to water flows. • Investigate extending Cape Range National Park to encompass Bundera Sinkhole and associated water inflows (Clarke & Spier-Ashcroft, 2003). Animal Disturbance • Implement a management plan for the control and eradication of feral goats in the local region (EA, 1999). Animal Predation or Competition • Manage threats to control potential introduction of exotic fish. Conservation Information • Raise awareness of L. exleyi within the local community. Enable Recovery of Additional Sites and/or Populations • Investigate options for enhancing or establishing additional populations.
Lasionectes exleyi Conservation Advice - Page 2 of 3 This Conservation Advice was approved by the Minister / Delegate of the Minister on: 3/7/2008 This list does not necessarily encompass all actions that may be of benefit Lasionectes exleyi, but highlights those that are considered to be of highest priority at the time of preparing the conservation advice.
Existing Plans/Management Prescriptions that are Relevant to the Species • Cape Range Remipede Community (Bundera Sinkhole) and Cape Range Remipede Interim Recovery Plan 2000-2003 (Black et al., 2001), and • Threat Abatement Plan for Competition and Land Degradation by Feral Goats (EA, 1999). These prescriptions were current at the time of publishing; please refer to the relevant agency’s website for any updated versions.
Information Sources: Black, S, Burbidge, AA, Brooks, D, Green, P, Humphreys, WF, Kendrick, P, Myers, D, Shepherd, R & Wann, J 2001, Cape Range Remipede Community (Bundera Sinkhole) and Cape Range Remipede Interim Recovery Plan 2000-2003, Interim Recovery Plan No. 75, Department of Conservation and Land Management, Western Australia Species and Communities Unit, viewed 10 April 2008,
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