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CAVE-DWELLING INVERTEBRATES

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					                   CAVE-DWELLING INVERTEBRATES
                                       Various species

Species Listed                               Status   Known Locations
Harvestmen
    Hickmanoxyomma cavaticum                   R      Hastings, Ida Bay, North Lune caves
    Hickmanoxyomma gibbergunyar                R      Mole Creek caves
Pseudoscorpion
    Pseudotyrannochthonius typhlus             R      Mole Creek caves
Beetles
    Goedetrechus parallelus                    V      Junee-Florentine caves
    Goedetrechus mendumae                      R      Ida Bay caves
    Idacarabus cordicollis                     R      Hastings caves
    Idacarabus troglodytes                     R      Ida Bay caves
    Tasmanotrechus cockerilli                  R      Mole Creek caves
Spider
    Olgania excavata                           R      Bubs Hill Caves
Cricket
    Micropathus kiernani                       R      Sandstone Cave near Dover

Status

All are RARE (R) or VULNERABLE (V)
(Tasmanian Threatened Species
Protection Act 1995), due to their
restricted distributions, small population
sizes and intolerance to environmental
change.

Description

Harvestmen
Hickmanoxyomma cavaticum
Hickmanoxyomma gibbergunyar
Both these species are troglobites. These animals are closely related to
spiders and wander around the cave walls and floor in search of prey.
This genus is endemic to Tasmania and provide important clues on the
evolution of cave fauna.

Pseudoscorpion
Pseudotyrannochthonius typhlus
This species is a troglobite. These animals are very rare. The genus is
a relic from before the break-up of the Gondwanan continent, and its
species are highly adapted for living in the cave environment - to the
point of losing eyes and pigment, having longer limbs and appendages,
and growing much larger than surface species.



Threatened Fauna Manual for Production Forests in Tasmania
This version current as at 10 October 2002
Beetles
Goedetrechus parallelus
Goedetrechus mendumae
Idacarabus cordicollis
Idacarabus troglodytes
Tasmanotrechus cockerilli
All these species are troglobites. The Tasmanian cave beetle fauna is
of great scientific interest. The species listed here include animals with
very reduced and lost eyes, and are often very rare within a cave.
Some Tasmanian genera are found exclusively in caves, with their
surface forebears long since extinct.

Spider
Olgania excavata
This species is a troglophile. Some species in this genus have entirely
lost their eyes. They live in small webs in cracks in the walls and floor
of caves, usually near water.

Cave cricket
Micropathus kiernani
This species is a trogloxene. These animals cluster in the entrances of
caves and emerge into the forest at night to feed. They provide a
major source of food for animals living in and unable to leave the cave
environment.

Distribution and Habitat

Most of these species (all the troglobites) are
unable to live outside the cave environment.
They are dependent on the stable, humid
atmosphere deep within caves. As there is
no light deep in caves to enable plant
growth, animals are dependent on input of
organic material from outside the cave (e.g.
leaf litter) for food. Cave food webs are
considered fragile and therefore vulnerable
to disturbance. The troglophile and
trogloxene, species prefer caves but aren't
completely dependent on them. Most of the
species are carnivorous as noted, although
the crickets and maybe the beetles are
omnivores.

The geographic ranges of cave-dependent
species are usually small, with species being


Threatened Fauna Manual for Production Forests in Tasmania
This version current as at 10 October 2002
found only in a particular cave region. This is because they can
disperse only through cracks in bedrock, or perhaps through soil layers
or forest litter on the surface, and so separate species evolve in
different cave areas.

Cave fauna may be threatened by disturbances in the catchment of the
cave which alter the environment within the cave (such as changes in
water quality or flow pattern, pollution of water flowing or seeping into
the cave, removal of litter input).

Cave localities are not given in this manual, but the presence of these
cave species is listed on the relevant mapsheet page.

Management Objectives for Production Forest Areas

•   To protect known sites and potential habitat for these species, and
    maintain habitat quality by minimising disturbance within cave
    catchments.

Reading

Doran, N.E., Eberhard, S.M., Richardson, A.M.M. & Swain, R. (1997).
  Invertebrate Biodiversity and Conservation in Tasmanian Caves.
  Memoirs of the Museum of Victoria 56: 649-653.
Doran, N.E., Kiernan, K., Swain, R. & Richardson, A.M.M. (1999).
  Hickmania troglodytes, the Tasmanian Cave Spider, and its potential
  role in cave management. Journal of Insect Conservation 3: 257-
  262.
Clarke, A. (1997). Management prescriptions for Tasmania’s cave
  fauna. Report to Tasmanian RFA Environment & Heritage Technical
  Committee.
Eberhard, S.M. (1999). Cave fauna management and monitoring at Ida
  Bay, Tasmania. Parks and Wildlife Service, Tasmania.
Eberhard, S.M., Richardson, A.M.M. and Swain, R.S. (1991). The
  Invertebrate Cave Fauna of Tasmania. Zoology Dept, University of
  Tasmania.




Threatened Fauna Manual for Production Forests in Tasmania
This version current as at 10 October 2002

				
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Description: CAVE-DWELLING INVERTEBRATES