Citazione:
Messaggio inserito da Mika
Esistono sottospecie di elegans?
E se si, sono sottospecie o solo varianti geografiche?
E in tal caso, come si possono riconoscere?
Caro Mika,
The scientist in the moment cannot accept subspecies in Indian Star Tortoises (Geochelone elegans). But, there are few different geographical variations in this species, easy to recognize and easy to differentiate.
In literature, and by side of many biologist, we are able to find differentiation in two "types" only, i.e. in Indian and Sri Lankan Stars. But, it is incomplete differentiation, i.e. highly reduced and wrong.
There are at least 3 (4?) geographical variation in Indian Stars inside of peninsular India, and, at least 1 (2?) geografical variation in Indian Stars at Sri Lanka Island.
It is very easy to see, there are few different carapace colors and scute patterns in Indian Star Tortoises, as well as plastron markings, too. Some Authors tried to make deffinitive work in this matter, but still incompleted and not so serious like Dr. Liu's work in Burmese Star Tortoises.
I am working in it myself very hardly in past two years, due to big quantity of Indian Stars being seen personaly in Europe and Asia, predominantly in Asian breeder's collections.
In these two years I collected big number of Indian Stars photos, from different localities and in different age. So, I hope, to be able to finish this work during next year, enable me to present my view in this matter to Tarta Forum.
Everybody can see, a north to south cline in carapace length exists through peninsular India, with Tortoises from the north being larger than those from the south (in opposite, Sri Lankan animals are even bigger!), but the size is not only difference between them. Also, the Tortoises from western India (and formerly, from eastern Pakistan) have a dull dirty brown or beige color, while those from southern India are more brightly colored. So, both could be color of size variations only, but it is not the right answer surely. There are few other clear differences between G. elegans from different places of peninsular India, having significatory morphological appearances.
Speaking about the difference between peninsular Stars ("Indian") and island's Stars ("Sri Lankan"), many authors (insluding Dr. Liu) found it, in:
a) stripes number, size and color, i.e.
"more numerous, thinner & orange-yellow stripes" on scutes of Indian Stars; and
"less numerous, broader, pale yellow stripes" on scutes of Sri Lankan Stars;
and
b)carapace pyramiding
"being more expressed in Sri Lankan Stars, than in Indian ones".
Of course, the second one is O.K., but is is not enough visible difference. Due to frequently inproper diet of G. elegans in captivity, there are significant number of over pyramided animals in peninsular Stars available, and they could be considered as Sri Lankan Stars. Anyway, Sri Lankan animals are more pyramided than animals from peninsular India surely!
On the other side, I cannot accept claim - Sri Lankan animals are having less numberous, broader stripes, while peninsular animals are having more numerous thiner stripes.
No - I have seen true Sri Lankan Stars with bigger number of thiner stripes, and also - peninsular animals with lesser number of broader stripes on carapace. It means, classification of geographical variations in Indian Star cannot be so simple and so reduced like this. Nobody tried to work in plastron marking differences, exact number, disposition, size and color of scute stripes seriously, as well in body shape (and the size) finaly!
Of course, Dr. Liu could not make final work in both species, i.e. Burmese Stars and Indian Stars all alone. He worked very much in his favority, i.e. Burmese Star being great expert in this species. For Indian Stars, we need to make great efforts to recognize this species well!
Finaly, I am repeating once more - independing they considered as close species, G. elegans and G. platynota are very far each other, and G. radiata appearing much intimate to G. platynota...
Yours sincerely, Marco