The other none native frog at San Rafflu Pool, Gozo

[MWP admin]

Regarding San Rafflu Pool, are the frogs the normal painted endemic frog? (looked a bit different?!) Or maybe I should ask - is there another amphibian pop? I hear sounds of 'toads' but was not sure if it was coming from some old duck

[RB]

Those frogs are not native species, someone put them there. And yes, they are VERY noisy in the breeding season.

[Zurrija]

I never saw native zringijiet close, but on the pictures local species looked really variagated, not like those dark green I saw this time near San Rafflu water edge.

I have couple of photoes of these frogs but not of very good qualifity as I really had to zoom... I'll search for them today and send them to the Forum.

They are really-really noisy, but I could clearly say the sounds came from frogs, not from the duck which was in the pool, too. There are even turtles, by the way

[MWP admin]

Thanks Zurrija. I would never left the place without photos of these creatures. They one I took looks like the painted frog at first glance, but now that you are pointing it out, they are quite too much varigated (or contrasting patterns) with that central green stripe.

Here are my best of the collection.

[IL-PINE]

They look like members of the genus Rana.
No idea which. Definitely not the native species.

[MWP admin]

Yes pine, you are right. I have been informed that the species is Rana bedriagae by Mr. Sandro Lanfranco.

[RB]

I think that that may be a misidentification, let's put it this way, that's what the internet seems to indicate.

Here is write up saying bedriagae (who knows the source of this info?? - maybe Lanf.?) but then the link below offers several pics which tend to eliminate bedriagae and confirm perezi.

From: http://www.club100.net/hotspots.html

"Malta
This is a small island quite far from the mainland and depending on this situation the herpetofauna is quite rich with nine species. As on many isolated islands there is an endemic species, the Maltese Wall Lizard (Podarcis filfolensis), wich is the only podarcis here. Two very rare species are the Algerian Whip Snake (Hemorrhois algirus) and the Mediterranean Chameleon (Chamaeleo chamaeleon), both probably introduced during the 19th century. The Whip snake is rare on the southeast part of the island, while the Chameleon is found on several sites. Another probably introduced species is the Cat Snake (Telescopus fallax) which can be found in the same area as the Algerian Whip Snake. More spread is Leopard Snake (Elaphe situla) and Western Whip Snake (Hierophis viridiflavus). Here are just two species of amphibians to be found, the rare Painted Frog (Discoglossus pictus) and the introduced Levant Water Frog (Pelophylax bedriagae). Other species on the island are Ocellated Skink (Chalcides ocellatus), Moorish Gecko (Tarentola mauritanica) and Turkish Gecko (Hemidactylus turcicus)."

But take a look at:

http://tolweb.org/onlinecontributors/ap ... 17424&sp=0

Perezi is identical to MWP's excellent pic, esp this one:

http://tolweb.org/tree/ToLimages/148410 ... 0732_b.jpg

I can well understand the possibility of this confusion happening, the species is more timid than the common frog and harder to photograph.

RB

[RB]

More bedrigae - different to the Gozo frogs, NO DORSAL STRIPE:

http://www.pbase.com/paulcools666/rana_ ... water_frog

RB

[MWP admin]

Really interesting RB. Its a pleasure to have interactive users like you onboard!

I am no expert so I will delve into this by showing the forum post to the person who suggested the name.

As you said, the internet source can be more into mistake than the Maltese person who suggested this since the latter would involve in depth study of the case .

We see the outcome, maybe you end up in some scientific journal

[IL-PINE]

wow!

[MWP admin]

Her is a link from the internet which claims to show Rana bedriagae.

http://www.herpetofauna.at/gallery/rhod ... riagae.htm

From our unexpert eyes, it looks without a dorsal stripe, but the experts would have an explanation. Maybe 3rd species?!

[MWP admin]

Here is an abstract of the authors who identified Rana bedriagae from Sarraflu, Gozo.
===========================================================


Occurrence of the alien Bedriaga’s frog (Rana bedriagae Camerano, 1882) in the Maltese Islands, and implications for conservation

ARNOLD SCIBERRAS and PATRICK J. SCHEMBRI


ABSTRACT —

We document the occurrence of Bedriaga’s frog Rana bedriagae Camerano, 1882 in the freshwater pool of L-Ghadira ta’ Sarraflu on the island of Gozo, one of the very few naturally occurring permanent bodies of water in the Maltese Islands, and a protected site.

The frog is an alien species that appears to have been deliberately introduced in the late 1990s and to have established a breeding population at Ta’ Sarraflu and possibly at two other sites on
Gozo and at one site on Malta. Spread of the alien seems to be through human agency, not natural dispersal.

Occurrence of the alien frog may have an impact on the only native amphibian, the Painted frog Discoglossus pictus pictus Otth, 1837, a protected species, as well as on the biota of the freshwater systems where the alien occurs, which are within or in close proximity to, protected sites and candidate Natura 2000 Special Areas of Conservation.

[MWP admin]

The question is if the specimen I photographed are a 3rd Rana spp. or whether this Rana bedriagae is that variable according growth or breeding season.

[MWP admin]

Hi guys,

Finally we can put a stone on this topic. The alien frog in that Gozo pool is
Rana bedriagae .

We have based a lot of our concerns and questioning according to the morphology of the photos, but unlike botany, identification od species in some orders of the Animalia, is not based on morphology, and the Anura order (Frogs and Toads) is one of those nasty ones.

Prof. P.J.Schembri wrote that water frogs can be securely identified only either through molecular analysis or through their call characteristics. Again not all calls are good but only those which are known as "advertisment calls" , that in childish words means "hello, I am here full of strength and ready to mate" Therefore ID of these frogs is by the ear not by the eyes.

Additionally, I found an internet source displaying this frog with a central stripe, and out of all wonders, the website below is managed by Prof. Ulrich Sinsch, incidentally the one whos method was employed in the ID of the frogs of San Rafflu.

http://www.uni-koblenz.de/~sinsch/html/sinsch/f_4.html

So after this info, there is no more room for speculation regards this frog - Rana baedriaga is the introduced alien at San Raflu Pool, Gozo.

Nice discussion and observations