Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
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 Endangered
Listing and Conservation Advices Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].
 
Commonwealth Conservation Advice for Mesodontrachia fitzroyana (Fitzroy Land Snail) (Threatened Species Scientific Committee (TSSC), 2013fj) [Conservation Advice].
 
Recovery Plan Decision Recovery Plan not required, included on the Not Commenced List (1/11/2009).
 
Adopted/Made Recovery Plans
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (43) (14/08/2006) (Commonwealth of Australia, 2006g) [Legislative Instrument].
 
State Government
    Documents and Websites
NT:Threatened Species of the Northern Territory. Fitzroy Land Snail: Mesodontrachia fitzroyana (Ward, S., V. Kessner, M. Braby & J. Woinarski, 2012) [Information Sheet].
State Listing Status
NT: Listed as Critically Endangered (Territory Parks and Wildlife Conservation Act 2000 (Northern Territory): 2012 list)
Non-statutory Listing Status
IUCN: Listed as Lower Risk (near threatened) (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Mesodontrachia fitzroyana [79111]
Family Camaenidae:Pulmonata:Gastropoda:Mollusca:Animalia
Species author Solem, 1985
Infraspecies author  
Reference Solem, A. (1985). Camaenid land snails from Western and central Australia (Mollusca : Pulmonata : Camaenidae). V. Remaining Kimberley genera and addenda to the Kimberley. Rec. West. Aust. Mus. Suppl. 20: 707-981 [867].
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific name: Mesodontrachia fitzroyana

Common name: Fitzroy Land Snail

The Fitzroy Land Snail is a large Camaenid land snail. The shell has a medium-yellow horn, a white lip and five to six whorls. The shell is between 17–23 mm in diameter and 10–14 mm high. The apex and spire are moderately elevated and somewhat rounded above (Ward et al. 2006a).

The Fitzroy Land Snail is restricted to the low limestone hills that are approximately 24 km east of Timber Creek and approximately 350 km south of Darwin in the Northern Territory, along the route of the Victoria Highway (Solem 1985; TSSC 2006z).

The extent of occurrence of the Fitzroy Land Snail is approximately 50 km² and the area of occupancy is thought to be much less than 50 km² (TSSC 2006z).

The following surveys have searched for snails, including the Fitzroy Land Snail:

  • Nine field trips to the Kimberleys and surrounding areas were made between 1974 and 1984 to collect land snails, particularly Camaenids (Solem 1984, 1988). Early trips were mainly aimed at general collecting while later ones focused on expanding the areas sampled. The Fitzroy Land Snail was collected on two trips, in 1980 and 1984. The majority of collecting was done by searching exposed limestone areas close to roads and tracks. Survey notes indicate that areas were searched thoroughly. Unfortunately, sites where no snails were located were not recorded, and many areas remain unexplored (Solem 1985, 1993).

  • Further surveys collected the Fitzroy Land Snail four times, first in 1985, and last in the late 1990s. These surveys included searches in floodplain areas surrounding the known limestone locations of the species. However, the species was not located at these locations. The next closest areas of limestone are to the west, but the snails found there belong to a different species (V. Kessner 2004, pers. comm.).

Very restricted ranges are a feature of several Camaenid snail species, althought they can be locally very abundant. It is considered that sampling has been sufficient to establish that the Fitzroy Land Snail has a very restricted range. Comprehensive searches and collecting trips, made in exposed limestone areas close to roads and tracks, have thoroughly searched the areas likely to contain the species. Further surveys of limestone outcrops in north-west Australia are considered unlikely to reveal new locations for this species (V. Stanisic 2004, pers. comm.; TSSC 2006z).

The Fitzroy Land Snail is only known from a single population 24 km east of Timber Creek and 350 km south of Darwin (Ward et al 2006a).

Reports from a 1985 survey indicate that thousands of Fitzroy Land Snails were found at the time (V. Kessner 2004, pers. comm.) however, three subsequent surveys in the late 1990s noted that specimens were very difficult to find. The species is suspected to have undergone a significant reduction in numbers in the period from 1985 to the late 1990s (TSSC 2006z).

The generation length of Camaenid snails, such as the Fitzroy Land Snail, is likely to be four to five years (TSSC 2006z).

The Fitzroy Land Snail is found under rocks in open eucalyptus woodland and in small patches of vine scrub thicket on pavement limestone (TSSC 2006z; Ward et al. 2006a).

The Fitzroy Land Snail is dormant in the dry season. The species goes into a state of torpor or hibernation (aestivation) in response to very dry conditions, or hot temperatures among the rocks, and emerges to become active in the wet season (Ward et al. 2006a).

The Camaenid land snails are hermaphroditic pulmonates which typically mature in their second wet season and may live up to 10–15 years (J. Stanisic 2004, pers. comm.; TSSC 2006z). On the basis of seasonal samples for several species, and dissection of more than 150 species of Australian Camaenids, Solem and Christensen (1984) found that there is a basic reproductive cycle common to Camaenids inhabiting monsoon climates (Solem & Christensen 1984):

  • Egg-laying and birth take place early in the wet season, and young reach half adult size in the same wet season, followed by aestivation through the dry season.
  • Young reach full shell size late in the second wet season, become functional males near the end of this wet season, and aestivate through the next dry season.
  • New adults are functional males in their third wet season with the female organs maturing late in the wet season, and the snails aestivate through the next dry season.
  • All specimens are functional hermaphrodites in their fourth wet season, and continue to be reproductively active for several more wet seasons.

The population of the Fitzroy Land Snail has declined substantially in recent years due to the species' susceptibility to hot frequent fires during the snail's dormant period in the dry season (TSSC 2006z). In both the wet and dry seasons, the species is also susceptible to trampling by stock, which may trample aestivating snails and reduce the covering vegetation (V. Kessner 2004, pers. comm.; TSSC 2006z).

Feral predators such as rats, mice and Cane Toads (Bufo marinus) may have a significant impact on the Fitzroy Land Snail in the future. Cane Toads are expected to invade the sites where the Fitzroy Land Snails occur and are likely to predate the species, as molluscs are a known component of the Cane Toad diet (Pearson et al. 2009; TSSC 2006z). However, doubt exists on whether Camaenid snails in north-western Australia are at risk from the invasion of Cane Toads. Pearson and colleagues (2009) investigated the possibility of spatial and temporal overlap between Cane Toads and the Fitzroy Land Snail at the Timber Creek locality. Twenty-five of the species were located and their habitat use was recorded and compared with Cane Toad habitat use of a site close by. The results indicate that, while the two species are active at the same time, places, and during the same temporal conditions, the Cane Toads would not have been able to forage on the snails because of the largely arboreal activity of the Fitzroy Land Snails and the low density of Cane Toads in the limestone habitats used by the snail.

The Commonwealth Conservation Advice on Mesodontrachia fitzroyana. (TSSC 2006au) recommends the following priority recovery and threat abatement actions for the Fitzroy Land Snail:

  • Promote protection of habitat from fire and grazing regimes.
  • Investigate population trends and the impact of threats.

The Department of Natural Resources, Environment and the Arts (Ward et al. 2006a) recommends the following research and management priorities:

  • Conduct further surveys to determine whether populations occur elsewhere.
  • Identify specific threats to the known population.
  • Better safeguard the known population through encouragement of appropriate fire regimes and protection from heavy grazing.
  • Protect the species from Cane Toads, if they are found to eat the Fitzroy Land Snail. (Cane Toads are known to eat other Camaenid spp. (Pearson et al. 2009))

The Commonwealth Listing Advice on Mesodontrachia fitzroyana (TSSC 2006z) and the Commonwealth Conservation Advice on Mesodontrachia fitzroy (TSSC 2006au) provide brief management recommendations for this species. In addition, Collecting biological specimens in the Northern Territory with particular reference to terrestrial invertebrates: guidelines to current legislation and permits (Braby 2007) is also available.

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
Agriculture and Aquaculture:Livestock Farming and Grazing:Grazing pressures and associated habitat changes Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].
Agriculture and Aquaculture:Livestock Farming and Grazing:Habitat alteration (vegetation, soil, hydrology) due to trampling and grazing by livestock Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Restricted geographical distribution (area of occupancy and extent of occurrence) Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Rhinella marina (Cane Toad) Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Predation, competition, habitat degradation and/or spread of pathogens by introduced species Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].
Natural System Modifications:Fire and Fire Suppression:Inappropriate and/or changed fire regimes (frequency, timing, intensity) Commonwealth Listing Advice on Mesodontrachia fitzroyana (Threatened Species Scientific Committee (TSSC), 2006z) [Listing Advice].

Braby, M.F. (2007). Collecting biological specimens in the Northern Territory with particular reference to terrestrial invertebrates: guidelines to current legislation permits. Northern Territory Naturalist. 19:35-45. [Online]. Available from: http://www.nt.gov.au/nreta/wildlife/permits/pdf/invertebrates.pdf.

Kessner, V. (2004). Personal communication.

Pearson, D., M. Greenlees, G. Ward-Fear & R. Shine (2009). Predicting the ecological impact of cane toads (Bufo marinus) on threatened camaenid land snails in north-western Australia. Wildlife Research. 36:533-540.

Solem, A. (1984). Camaenid land snails from Western and central Australia (Mollusca: Pulmonata: Camaenidae) IV Taxa from the Kimberley, Westraltrachia Iredale, 1933 and related genera. Records of the Western Australian Museum Supplement. 17:427-705.

Solem, A. (1985). Camaenid land snails from Western and central Australia (Mollusca: Pulmonata: Camaenidae) V Remaining Kimberley genera and addenda to the Kimberley. Records of the Western Australian Museum Supplement. 20:707-981.

Solem, A. (1988). Non-camaenid land snails of the Kimberley and Northern Territory, Australia: I. Systematics, affinities and ranges. Invertebrate Taxonomy. 4:455-604.

Solem, A. (1993). Camaenid land snails from Western and central Australia (Mollusca: Pulmonata: Camaenidae) VI Taxa from the Red Centre. Records of the Western Australian Museum Supplement No 43. Page(s) 983-1459.

Solem, A. & C.C. Christensen (1984). Camaenid land snail reproductive cycle and growth patterns in semiarid areas of North-Western Australia. Australian Journal of Zoology. 32.

Stanisic, J. (2004). Personal communication.

Threatened Species Scientific Committee (TSSC) (2006au). NON-APPROVED Commonwealth Conservation Advice on Mesodontrachia fitzroyana. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/mesodontrachia-fitzroyana.html.

Threatened Species Scientific Committee (TSSC) (2006z). Commonwealth Listing Advice on Mesodontrachia fitzroyana. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/mesodontrachia-fitzroyana.html.

Ward, S., V. Kessner, M. Braby & J. Woinarski (2006a). Threatened Species of the Northern Territory. Fitzroy Land Snail: Mesodontrachia fitzroyana. [Online]. Department of Natural Resources, Environment and the Arts, Northern Territory Government. Available from: http://www.nt.gov.au/nreta/wildlife/animals/threatened/pdf/inverts/Mesodontrachia_fitzroyana_CR.pdf.

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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). Mesodontrachia fitzroyana in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Tue, 23 Sep 2014 14:03:17 +1000.