fieldherping.eu

...Continued from Part 1 =>http://www.fieldherping.eu/Forum/viewtopic.php?f=13&t=2539&p=25538#p25538

Walking in the forest I stumbled upon the ruins of an old house where I found more P. muralis and a young Coronella austriaca in a pre-shedding stage.





Near the ruins there was a small shaded forest stream where there were yet more P. muralis and P. ridibundus, but also Rana dalmatina and a newly metamorphosed Salamandra salamandra which was still in the water and which I was very happy to see in this time of year. Inspired by this little guy I thought I'd look around the vicinity of the stream to see if I can find any adults. I flipped a few stones and I was lucky enough to get a big adult female which looked gravid to me.

















I wasn't expecting to find much in this hot and dry time of the year with little time to search but all and all I was pretty satisfied with the result, and of course a "new" species on the list is always an exciting thing. Sometimes when you don't have plans you might find more than if you do, and those unexpected finds are really great.

crayfish looks like native Astacus astacus

Mario Schweiger wrote:crayfish looks like native Astacus astacus

Thanks Mario! I wasn't sure because I'm used to seeing them in big lakes/ponds or rivers never in a small cold mountain stream like that one. And they were much smaller than the ones I've seen in lakes.

ok, it maybe a Austropotamobius torrentium, stone crayfish.
looks very similar.
has been Astacus before (I think a ssp. of Astacus astacus too, but I'm not sure)

Mario Schweiger wrote:ok, it maybe a Austropotamobius torrentium, stone crayfish.

I think you are right. Thanks again. I've changed the photo caption.

Nothing regarding the fire salamanders from the salamander lovers...?

I've never found any larvae at this time of year even at known sites, so I was surprised to find this newly metamorphosed one. It was also the only one there. Was it late in its development?

What about the adult? Any experience in finding them at this time of year and in the south? I thought that was pretty lucky having in mind the dry and hot weather. Was it aestivating and was it indeed gravid like I thought?

Cool finds, a lot of the time so accidental ones are more exciting than dedicated herping. The Salamandra looks quite gravid to me and waiting to deposit larvae. My mentor and life counselor Jeroen Speybroeck should have something to say about it for sure.

Seasonality in reproduction and life history of fire salamander populations is fairly flexible.

Females can store sperm inside their body without using it for several months, if not a year. Once embryos are present, again, they can "decide" to release them whenever they "prefer", e.g. in response to suitable weather conditions (namely, those which guarantee that a period is starting that will be suitable for larval development). At the population level, this results in large variation between females and a long period of potential larval deposition. At my spot, larval deposition goes at least from November until April, but most likely starts already in October, if not September. Gravid females (defined as clear cases only, ruling out confusion with animals that only had a good meal) are present here from August until March. However, this differs greatly between areas - if I move east to more continental climate (even in my own country), larval deposition happens within a much shorter period, i.e. after winter only (so not already throughout autumn and winter, continuing in spring).

Larvae deposited towards the end of the main deposition period may remain in the water until the drier season is over. Depending on the location, this "dry season" may also be the cold season. It's that type of late larvae who typically show more pigmentation. Suboptimal conditions (short growing season etc.) may also cause larvae to remain in the water for a longer amount of time. Other suboptimal conditions, namely the water body drying up, may speed up the process, causing metamorphosis at smaller size.

This adds up to the fact that (theoretically) both larvae and gravid females can be present not only simultanously, but also throughout the year, with important variation across the species range.

Matthijs, thanks for confirming the female was gravid.

Jeroen, now you're just showing off...I'm kidding, of course Thanks for the comprehensive explanation. I was sort of expecting that but I thought there might be more precise statistics on time of larvae deposition and development from this part of Europe. I'll check local literature to see if there's anything there.

Ilian Velikov wrote:Jeroen, now you're just showing off...

All for the benefit of helping Matthijs to make something useful out of his otherwise futile existence.

Ilian Velikov wrote:I was sort of expecting that but I thought there might be more precise statistics on time of larvae deposition and development from this part of Europe.

The closest you'll get is Germany, for as far as I know. I bet that within Bulgaria variation will be important, in view of proximity to the sea and altitude. Areas with harsh winter conditions are likely to, as I explained, only have a post-winter deposition season, making old larvae in August not a rare sight + there's the story that they may stay in the water until the next wet period if they don't get out of the water in time. But I'm repeating myself now.