Click Here for Tortoise Town!
News & Events:
Posted by Scott Eipper on May 07, 2002 at 04:34:54:
In Reply to: Re: Cannia australis and "Pseudechis".....more posted by WW on May 06, 2002 at 12:09:56:
: Actually, the viviparous/oviparous difference is a lot less of a major difference than you might expect - this can vary even within individual species - for instance, both Lacerta vivipara in Europe and Lerista bougainvillei in Australia have both viviparous and oviparous populations within the one species! Viviparity is really not much more than retaining eggs until the time of hatching, so the differentiation required is actually relatively minor.
I am unfamiliar with any of the Lacerta genus....couple of pics of viridis and a basic species account of it is about it...so I won't comment on them.
I am however fairly familiar with Lerista bouganvilli ..probably the most common reduced limb skink in Victoria!
The Bass Strait Island populations (And probably the pop from Tasmania) are viviparous..with 2 to 4 young born in Summer while the Mainland pop is oviparous. While they are the same ancestor I doubt they are actually the same species if not sub species.
Ehmann..1992 States in his first line of the Species account of L. bouganvillii " it is quite likely that at least 2 species are presently assigned to this name".
Look at the Tiger Snakes from the Bass Strait....7 ft Chappell Is Tigers (average about 5 ft...closest mainland pop... is probably the South Aussie Snakes...Peninsular Tigers Come to mind.. their average is about 3 ft..and max out around 5 ft. Thats 2 feet of difference, as well as the morphylogical and diet differences.
I know that this is a case of evolution due to the lack of prey for mid sized elapids..large get more food...more successful..and thus size is bred in. But still However King Island, Flinder's Island and Tasmanian Tigers are still separated at subspecies level from their South Australian counterparts.
: I am not surprised - the level of mtDNA sequence difference bewteen guttatus and colletti is quite remarkably small - 1.7% in ND4 - this sort of level is more usually associated with variation WITHIN rather than BETWEEN species. If I didn't know the snakes better, I would have thought that they are one and the same species from that data. These two species obviously diverged from each otehr very recently.
They where classed as the same species for many years, C. guttaus colletti....and then..quite rightfully split.
On a totally unrelated topic...have you sent that Naja paper?