Thursday, Jan 29, 2009 at 19:16
In comparison to Yabbies, Crabs are much more widespread and were observed either directly, or by
burrows, in a great many temporary watercourses as
well as in temporary
waterholes in watercourses.
Crabs have been recorded in a variety of locations north of about 22º 44' latitude. To the south of this, the
only records in the arid NT are from the Stony Plains Bioregion at Wall Hole (25º 57' 43''; this survey)
and downstream at Charlotte Waters on the lower Coglin Creek (Horn Expedition). There is no record of
Holthusiana in the MacDonnell Ranges Bioregion, either in the more elevated MacDonnell Ranges or in
the other ranges with lower elevation and less relief (height above the plain), such as the George Gill
Range.
Crabs are considered to be abundant in the Dulcie Ranges and Davenport Ranges. Of records to the north
of the MacDonnell Ranges bioregion, the most southerly records were specimens from the Dulcie Ranges
and observation of burrows at a large claypan and Bluebush
swamp on Tarlton Downs Station (both at
about 22º 44' S). Specimens or body parts were collected at various other locations including,
JunctionWaterhole on the Sandover River, creeks in the Reynolds and Yundurbulu Ranges, including some very
temporary
waterholes,
waterholes in the eastern and northern drainages of the
Davenport Range, both
major and minor drainage lines in the
Mitchell Grass Downs and Channel Country bioregions, and a
claypan in the
Mitchell Grass Downs.
Holes in banks were also observed in clay/loam banks of minor upland creeks in the Dulcie Ranges and
Reynolds Range; and in a bank of a sandy river bed (Woodforde River) with no
waterholes in the vicinity.
Although these observations cannot be confirmed as being burrows of Holthusiana, if they are, then they
may be indicative of a broad range of inundation regimes that the inland crab can tolerate. Alternatively,
they may indicate surprisingly long range dispersal from areas with more frequent inundation regimes.
The distribution and physiology of inland crabs (Holthusiana transversa) were reviewed by Greenaway
(1984) and report that they survive dry periods in ‘dry’ burrows but may depend on some soil moisture to
prevent unsustainable loss of body moisture.
FollowupID:
614639