Long-tailed Orb-weaving Spider
S16 Male: ventral
Ellura
Banded Orb Spider
Female: dorsal, close up
 
                      
Long-tailed Orb-weaving Spider (Argiope protensa)Class: Animals (Animalia) - Jointed Legs (Arthropoda) - Spiders, Scorpions, Mites & Ticks (Arachnida)
Order: Spiders (Araneae)
Family: Orb-weaver Spider (Orb: Araneidae)     iNaturalist Observation
Species: Long-tailed Orb-weaving Spider (Argiope protensa)
This Photo:     🔍S17 Female: ventral🔎
Synonym: Argiope extensa
Other names: Tailed Forest Spider or Teardrop Spider

Thank you Matthew Connors, David Muirhead & Natasha (Ethmostigmus) for confirming the id of this species for us

General Species Information:
Found on Ellura (in the Murray Mallee, SA) and elsewhere
Probably the most varied invert we come across; variations in colour pattern & body shape - occuring in one individual at times. Spiders can also "shrivel up" when hungry or just laid eggs, in this case giving them a blunt tailed apprearance rather than the typical pointy tail we see in photo's.
We have tried to highlight how each individual can change it's stripes and tail length. Please note specimen ids (S1, S2, etc) to compare the differences that occur within one individual.
We suspect the stripe change is to do with breathing; perhaps blowing it'self up in some defensive mechanism?
The males have quite different palps. It's quite possible they are different species as the palps are diagnostic in male spiders. It may also be a juvenile vs mature specimen variation. Or some damage caused due to breeding?
Recently it was recognised that A. protensa & A. extensa are actually the same species.
With the "tail" being able to be retracted, size is a difficult thing to compare. Should probably do the same as reptiles & measure to the vent; or spinnerets in this case.
They range in size from ~3mm for the Juvi, ~4-6mm for the males, ~6-18mm for other females. 3 to 18mm is an extreme size variation for spiders, again suggesting different species or unusual for spiders in that juveniles look identical to adults; which goes against the notion these vary so much

We've had a female living in our shade house, whose grown dramatically over the last 2 weeks; she's now the biggest we've measured at ~18mm long (S17). We've now seen with her that the highly reflective/silver colour are silver hairs. Notice her large "epigeal scape".
On the same day we caught a male (S16) which shows they are quite crab-spider like.
We have photographed 16 (3 male) in Jan, Feb, Apr, May, Jul, Aug, Oct, Nov & Dec.

Copyright © 2022-2023 Brett & Marie Smith. All Rights Reserved. Photographed 09-Dec-2022
This species is an Australian Native Species, not listed in the SA Murray Mallee Survey of 2010.