CROATIA 2013

 

Amphibia: CAUDATA (Newts & Salamanders)

Unlike the photo-trips to Spain (2011) and Greece (2012), one of the target species for the 2013 trip to Croatia was an amphibian, a unique member of the Caudata, one of the strangest amphibians on the planet.

Salamandridae:
Several newt or salamander larvae were seen but not captured in streams at the Velika Gorica location southeast of Zagreb. Their identification was not determined.

Protidae:

Proteus anguinus - Olm
The Olm (Proteus anguinus) is a strange neotenic salamander, one that retains its juvenile (larval)body-morph, including the red feathery gills, into adulthood and breeds in that condition. It is also a deep cave species that inhabits pitch-black flooded caverns, living in temperatures not much above freezing. Slow-growing, slow-moving, it can live to over 70 years, possibly 100 years of age, but never larger than 25cm. This cave-dweller is almost blind, although it does possess small pigmented spots where regular eyes would be located in other salamanders, yet it makes a successful living, feeding on soft-bodied invertebrates. Within its realm it is the top predator, the tiger of the depths.

So strange is the Olm, which used to be referred to as "the human fish" that is also virtually inhabits its own unique family, the Proteidae, although the mudpuppies of North America (Necturus) are also included in the family. The Olm is only found in the karst caverns of coastal Slovenia, Croatia and Bosnia and I had wanted to meet them since I obtained the fascinating book Proteus: the mysterious ruler of Karst darkness* over 20 years ago. In more recent times this unusual amphibian was selected by Sir David Attenborough as one of his ten Attenborough Ark animals.

When I expressed by desire to see an Olm in Croatia, Neven contacted his friend Dušan Jelić who had taken Sir David to visit the olms of Istria and Dušan agreed I could come along on the next trip to capture two more specimens for the research project.

While Dušan and his team were diving for olms in one of the caves near Novigrad Neven, Ivo and I visited the Baredine Caves to see some specimens relocated for tourists to view. Later at Zagreb Zoo I was able to photograph specimens from Gorski Kotar and Dalmatia, the latter a curious yellow phase. All photography was done with the minimum disturbance to the animals. I feel privelaged to have finally met not one but several olms from different Croatian locations. Another time I would like to cave dive to see them in their own environment, 30-50m down in freezing cold, pitch-black cave waters.

* Proteus: the mysterious ruler of Karst darkness. 1993 Vitrum Pub., Ljubljana, Slovenia.

 

Olm,
Proteus anguinus

Novigrad, Istria
Olm,
Proteus anguinus

Novigrad, Istria
Olm,
Proteus anguinus

Gorski Kotar
Olm,
Proteus anguinus

Gorski Kotar
Olm (yellow phase),
Proteus anguinus

Dalmatia

Another strange inhabitant of the dark watery depths, although not an amphibian, was the Istrian cave pill-bug (Monolistra bericum hadzii), a member of the family Sphaeromatidae (Isopoda) which are confined to Slovenia, Croatia, Bosnia Herzegovina and Italy. Several species of Monolistra are listed as Endangered or Threatened by the IUCN.

Istrian cave pill-bug,
Monolistra bericum hadzii
[Isopoda: Sphaeromatidae]
Novigrad, Istria