New
phreatoicidean isopod generaNew
phreatoicidean isopod generaPonderella Wilson & Keable, 2004
Eremisopus beei Wilson & Keable, 2002
Peludo paraliotus Wilson & Keable, 2002
Ponderella
is the sole genus in the new family, Ponderellidae, that Dr
Winston Ponder (Australian Museum) collected from Bundoona Springs, Eulo
Mound springs Supergroup, Queensland, Australia (27°57.15'S 144°46.21'E),
in flowing water at spring head and outflow (15-20cm from spring head). See
Wilson and Keable, 2004 for the description.
Reference: Ponder, W.F. (2004), Queensland Mound Spring Aquatic Invertebrates -- a report on the Barcaldine and Eulo Spring Supergroups, unpublished report to Australian Government Department of the Environment and Heritage.
This animal is a male phreatoicidean isopod, approximately
3 centimetres long, collected near Kalumburu, Kimberley region of northern Western
Australia. This species is a representative of another unique taxon given the
name Eremisopus, or "lonely isopod" by Wilson
& Keable, 2002.
Cameron Bee, then a freshwater fish specialist from Sydney Aquarium, brought two of these isopods in May 1997. Cameron had a small colony in his home tank for over a year. They appear to be quite hardy. Camron's video of these animals has been incorporated into a multimedia interactive that can be seen at the Australian Museum's Biodiversity Gallery. The large specimen above survived from May 1997 until January 1998 in my office with minimal care. During that time it moulted 4 times. Specimens of this new species is extremely active and, when disturbed, swims with strong strokes of the pleopods (swimming legs) as well as running motions of anterior legs.
Camron also gave me a female with several young in the brood pouch. The female moulted to a breeding condition but died for no apparent reason within a month. I suspect the species might breed only once during its life time. One of the young survived in the tank until February 1998).
The image to the right is of a smaller adult male, curled up in a typical phreatoicidean
resting/defensive position. This specimen's colouration is somewhat more reddish
than the larger male. Pigment on the external cuticle, perhaps picked up from
the environment, causes the red colour. I have observed similar environmentally-caused
reddish colouration in Eophreatoicus species from some streams in Kakadu
that were stained with reddish minerals (iron oxides?).
Because the right mandible of this species has a lacinia mobilis, the
species is a member of the family Amphisopidae, using the older classification
established by Nicholls (1943). Wilson and Keable (2002),
however, have found this family to be non-monophyletic as originally composed,
but it can be redefined with a smaller set of genera, including this genus.
The species shares the characters with other phreatoicideans but the pleotelson
of this species (shown at right) is unusual.
In Wilson and Keable
(2002), other genera from the South Coast of Western Australia are described.
The plate to the left illustrates the back end of the body of Peludo paraliotus,
a new genus from Cape Le Grand, near Esperance, WA. In 2002, Park rangers have
observed land migrations of many animals.
(updated March 2006)
For more information, email Buz Wilson, Australian Museum