frog eggs - species?

[Tibor Sos]

dear all, I found several clutches of amphibian eggs, are you familiar with this type? the habitat (Suceava river) is the home of Bombina variegata. the eggs were found in the slow flowing part of the river...

[Ilian Velikov]

Hi Tibor,

What I surely know is that these aren't Bombinatoridae eggs, neighter Bufonidae nor Pelobatidae !..So they are of some kind of a Ranidae eggs!..The white spots on the eggs make me think that they are of Rana dalmatina! They always deposite them in shallow water (less than 40 cm) but the size,compared to that coin looks very small! I'm puzzled,too! Anybody else?

[Mario Schweiger]

These are NO Bombina eggs - much to many in one clutch!
I´m with Ilian - these are Ranidae eggs!
Which species occur there?
At this time of the year - although quite late - the should be Pelophylax eggs?

Mario

[Tibor Sos]

the presence of Pelophylax ridibundus is almost sure. and from the brown Rana's I think could be Rana temporaria or R. dalmatina, although the most common is the R. temporaria. but we found metamorphosed R. temporaria in the area... and of course is to late for egg deposition for R. temporaria. the third species, the Rana arvalis is also present in the area, but I don't know were exactly... the place is interesting, the time and even the form of egg clutches. thus all aspects... or maybe is not amphibian?

[Tibor Sos]

for better comparison the coin has 2,4 cm diameter...

[Ilian Velikov]

OK, I read some additional info and here's what I think: They are not R.temporaria nor R.dalmatina, because it's too late for them (I didn't know the photos are that recent!). It's late for Pelophylax,too and even if it wasn't the eggs are in very small numbers for this species! If the coin is 2,4 cm ,it means that the egg clumps are about 4-5 cm! The only frog with that small eggs is Hyla arborea! It's true they deposite them in small rounder clumps but these could've been disturbed by the current of the river! Also H.arborea eggs turn from brown to white when developing, and the most important thing :

"....Reproduction occurs from April - May, but sometimes in March, June or even late July. .... Clutch contains about 200-2000 eggs deposited in portions, usually having the form of small rounded clumps containing from 3 to 100 eggs."

Reference: http://amphibiaweb.org/cgi-bin/amphib_q ... es=arborea

So,I think 99 % - Hyla arborea!

Ilian

[Tibor Sos]

another interesting pattern is that in the 3rd picture the clutches seems to belong to the same deposition (thus to the same female)... in the same trip I found a place near Moldova river close to the alpine bioregion with Hyla still involved in reproduction activity. I even saw the moment when the female lays it's eggs and the moment when they were attached to the plants... could be a Hyla, although I still not convinced...

[Ilian Velikov]

Well,according to the literature I've read no other amphibian reproduces that late in the year and those are definitely anura eggs! Besides, other things match Hyla, too...so, enough for me! Anyway, maybe there's someone with greater experience with amphibian eggs, who can help? Otherwise I don't see a way of determinating the eggs except DNA test...

[Jürgen Gebhart]

I found this year a few Hyla arborea spwan. viewtopic.php?f=10&t=129
I`m pretty sure that those eggs in your pics are from Hyla arbora.