Ptychozoon and other gecko species ID and sex determination-personal paper

thorrshamri · #1 (**permalink**) 17-01-2008, 03:30 AM

A short note on Ptychozoon sexing and species determination kuhli vs. lionotum ,Annandale 1905

After having wondered for months whether my flying geckos were of the same species or not ,I decided to make a special picture thread to put into obviousness the species characteristic features and show how to sex them .

No valid key for all Ptychozoon species does exist so far .I will only take into account the two most common species in the herp trade ,P. kuhli and P. lionotum ,other species are far more difficult to find and leave less doubts to the hobbyist in search of correct ID.

My Ptychozoon kuhli pair :

1. Tail shape
1.1 Tail tip :

P. lionotum has a relatively short and narrow tail end ,whereas P. kuhli’s tail shown here ends in a broad ,spatula-shaped tail .

1.2 Serrated tails

It is generally believed a tail serrated backwards indicates P. lionotum while a tail serrated straight ,making a right angle with the tail axis ,is typical of P. kuhli .None of the scientific papers published asserts this .Tails are serrated in both species and some kuhli specimens may have tails serrated slightly backwards ,so it does not count as a specific feature .

2. Head and tongue

P. kuhli’ s tongues display in most cases ,but not all ,a black tip .A whole pink tongue would indicate in 90% of cases a P. lionotum .Heads of both species are similar ,I have made a close-up pic to show the scalation of the labials .

3. Color

Both species are often prone to color changes according to heat ,lighting ,stress ,and environmental criteria .Color is in no way a means to differentiate both species .

4. Inbreeding

No case of kuhli x lionotum intergrades were ever reported .It would be wise to think such hybrids are impossible ,both in the wild and in terrariums ,as both species are partially sympatric .

5. Dorsal tubercles

2-6 rows of spiny ,tiny scales protruding and called tubercules are a distinctive feature of kuhli adults (for both sexes ) whereas lionotum don’t have any such tubercles .

P. lionotum (Photo courtesy Henke from Sweden ):

P. kuhli :

thorrshamri · #2 (**permalink**) 17-01-2008, 03:31 AM

Green arrows on the above shots indicate the position of the tubercles .

6. Forefeet :

All four feet are webbed and bear strong claws .In P. kuhli ,the toes in the forefeet are all gathered by the webbed skin between the toes .In P. lionotum ,the toe situated the nearest to the body in both forefeet tends to be separated from the others .

7. Sexing

Ventral view :

Hemipenal bulges are less obviously noticeable than in other gecko species ,but the row of pre-anal pores only seen in males is unmistakable .

Hervé Saint Dizier ,© January 2008

Bibliographic references :

New Species of Parachute Gecko (Squamata: Gekkonidae: Genus Ptychozoon) from Northeastern Thailand and Central Vietnam ,
Rafe M. Brown,
Copeia, Vol. 1999, No. 4 (Dec. 17, 1999), pp. 990-1001

First record of the smoothed-backed parachute gecko Ptychozoon lionotum Annandale 1905 in Indian mainland ,S. Pawar & S. Biswas ,Asiatic Herpetological Research ,vol.9 pp. 101-106 ,2001 .

Thanks to Hans Kam from Malaysia Nature Information for his help .

Master_Of_Darkness · #3 (**permalink**) 17-01-2008, 02:34 PM

very interesting. You have some good photos too

Reiyuu · #4 (**permalink**) 17-01-2008, 02:46 PM

Wonderfull informative article

thorrshamri · #5 (**permalink**) 24-01-2008, 02:15 AM

Sexing of other species :

Rhacodactylus auriculatus (aurics ,gargoyle geckos) :

They can be sexed from 6-8 months of age.

Cresteds are far more complicated to sex ,as hemipenal pockets may appear in males of 10 months age ,sometimes more than this!

Web-footed geckos (Pachydactylus (ex Palmatogecko) rangei):

Males can be sexed very soon too ,about 5-6 months of age. They have a sort of "growth" visible at the base of the tail :

Male:

Female:

Chondrodactylus turneri (Turner's gecko ,also mistakingly sold as Bibron gecko)

Males have 2-4 rows of spiny scales around the cloaca area whereas females don't have such spines .More ,in this species ,males have white spots on their backs while females don't have any.

Male-white spots on the back:

Female-no white spots:

The spines around the male's cloaca are also a distinctive feature of many Southern African species :Chondrodactylus angulifer (Giant Ground Gecko ) and many members of the Pachydactylus Genus.As for Giant Ground Geckos ,males have also much wider heads than females.

Gekko ulikovskii ,Gekko gecko ,Gekko vittatus ,Gekko marmoratus ,Gekko smithi (Tokays ,golden geckos ,palm geckos and all members of the Genus):

Males have a row of preanal pores which is pretty obvious while females don't have any of such pores:

Mez · #6 (**permalink**) 24-01-2008, 08:31 PM

really informative post, although i have to disagree on the sexing of Gekko gekko, i know the sexing of these certainly is not a case of "one has pores, the other does not". Perhaps Peter F will come in and contribute to this thread if he sees it

thorrshamri · #7 (**permalink**) 25-01-2008, 02:49 AM

Ok,let me be more precise then

.
As you can see in this close-up view of my own Gekko vittatus female ,pores are indeed present but much less obvious than in males. More, males' pores exsude a waxy ,brownish ,pheromone-like substance which is not the case in females

.