Wednesday, December 24, 2008


Manu Esteve, postdoc from University of Toronto is studying behaviour of the Salmonidae family (this family includes trout, salmon, grayling, charr and several others). He recently published some pictures from his expedition to Slovenia, observing the spawning habits of marble trout.

Thursday, December 18, 2008

Urška is back

Urška has returned from maternity leave last month. She has noticed some changes on our site and wanted an animated gif that some BTGR members already have.

And after a few minutes, the result:

Wednesday, December 17, 2008

An interview and a fishing story

James Prosek was interviewed by The Itinerant Angler, you can also download the interview (mp3, 41 MB). Among other things he mentioned our group and one of the more memorable field trip. He mentioned that he personally wasn't there, but Steve and Aleš often entertain us with the story.

Fishing story

In 2004 a field trip to Montenegro was organized, involving people from Austria, Slovenia and Serbia, along with local biologists and fisherman. The primary motivation for this trip was to search for the extremely rare and perhaps extinct form of softmouth trout from the Zeta River. The group was well equipped to sample trout, bringing several experienced fly-fisherman, an inflatable boat, and a 5 KW stationary electro-fishing generator, lugged all the way from Austria. The first glimpse of the Zeta generated quite a bit of excitement in this fish hungry crew. The river was surprisingly large and deep, lined with overhanging trees, and teeming with invertebrate life. While we did not necessarily expect to immediately find softmouth trout, we assumed that other trout would be plentiful. However, it quickly became painfully obvious that our experienced and well-equipped crew lacked a certain something necessary to catch Zeta River fish. The first reaction was natural – there are no fish! But each evening around sunset a local guide, Mlađen, who was observing us with some amusement the whole time, slipped away from the café veranda overlooking the Zeta - within an hour or so five or six plump freshly brown trout were slapped down before our eyes. Suspicions, confusion and frustrations were being muttered among us before the fourth evening when Mlađen offered to take Steve along and open Zeta’s door of enlightenment. Some may have thought there was a pond or hatchery around the bend that Mlađen would finally reveal, but instead he pulled one shy trout after another off the bottom of the Zeta with a Tyrolean nymph rig, sometimes from the same run where Steve had just thrown the same rig, 20 times. The rig was key, but not in anyone’s hands as it seemed that only Mlađen had some kind of Dr. Dolittle-like bond with Zeta’s trout. Nonetheless, even he could not come up with any softmouth, are real quarry.

Nearing the end of our week, the pessimism had reached its peak and some of us took a side trip to visit the famous monastery Ostrog, nestled into the high cliffs of the upper Zeta valley. According to common belief, wishes made in certain holy nooks of the monastery can come true. Maybe this is really so, because later in the day upon returning to the river we were approached by a local man who had heard of our struggles to find softmouth trout. He claimed to know where some were, in a small tributary of the Zeta, a few hundred meters from that all too cosy café on the banks of the Zeta. This was our last chance, though we were skeptical. Our skepticism increased as we gazed into the little stream’s clear waters which, like those of the Zeta, revealed no image worthy of even a mirage of a trout. But Johannes, the Carinthian baker who doubles as one of the more well-known explorers of exotic populations of Salmo, quickly donned his snorkelling attire, and made a survey more reliable than any we could have managed with fly lines or electrofishing gear. There were indeed softmouth trout in the stream!

Now we just needed to catch a few. A circus-like atmosphere soon developed, as we dragged the inflatable boat and electro-fishing gear across a meadow, attracting not only an increasing number of people, but a local television crew as well. As fate would have it, the Zeta softmouth, like the Zeta brown trout seemed immune to electricity, managing to stay on the move and just outside of the field around the anode, as if they were well trained. Our growing frustration was being intently monitored by Đoko, the guy who told us about this secret location. Afterall, he had PROMISED we would catch fish. Suddenly he couldn't stand it any more; he slipped into his wet suit, complete with mask, snorkel and fins and waded slowly into the shallow borders of an otherwise three meter deep pool. Observing his gesticulations, we slowly realized what his intention was: he wanted to dive with the anode pole in his hand and try to “harpoon” the fish with the electric field from a close distance. As the vision of this Rambo-esque plan unfolded in everyone’s minds there were varying degrees of resistance, ridicule and shock. With television cameras ready to roll, a multilingual cacophony rose around the pool as each person attempted to define their level of involvement, ranging from pure disassociation to neutral curiosity and on to legal culpability as expressed by Steve who had organized the Austrian crew and University owned electric-fishing set-up. He screamed: “No, no, no…!” But Danilo, from the University of Montenegro tried to explain to Steve that the man had indeed promised we would catch softmouth, and thus, by some rural code of honour he was determined to deliver, and there was nothing we could do to stop him. The decision was made to proceed, but with pre-determined hand signals and a hand on the off/on switch of the generator. Đoko finally got hold of the pole and quickly dove into pool. His hand went up, signaling for the juice, but he quickly emerged shaking his head in disappointment as the generator was correspondingly shut off. He dove again, gave the sign and everyone gasped at the sight of a swirl and a few bubbles – the electricity was only on for a few seconds, but Đoko emerged triumphantly with a softmouth trout in his net, igniting a cheer and celebration on the banks as if a golden-goal had just crossed the net. The act was repeated and several softmouth were landed in a similar fashion.

There were long debates on the dangers and dynamics of electric currents in water, of grounds and wet-suits and insulation. The popular outcome of this action was most likely the result of the fact that the man was indeed quite distant from both the anode and the cathode, with the electric field held out several meters in front of him at the end of a long anode.

P.S. Please note that the authors adamantly discourage anyone from repeating the actions described in this story. Fishing with electricity can be dangerous and should only be done by licensed operators, and all safety regulations should be followed, which in most countries explicitly forbids any form of diving during a sampling action.

Monday, December 15, 2008

Annual testing of marble trout from zone of hybridization

Just like last year, we performed genetic testing of fish from the zone of hybridization. This year we have received fin clips from 33 individually tagged trout from 2 locations: the River Tolminka, tributary of the River Soča and from the River Soča just below the town of Kobarid. These samples were checked for non native genetic characteristic on 5 nuclear genetic markers (each genetic marker in 2 copies, one allele inherited from each parent) and on 1 mitochondrial genetic marker (in 1 copy, inherited from the mother only). Out of 33 samples, 8 show signs of hybridization with non native trout, 1 sample (sample 20) will not be used because of low quality of DNA isolate. Eggs and sperm will be taken from 24 trout with no detectable brown trout genetic characteristics, fertilised and raised in the hatchery and released back in the zone of hybridization.

Below is a simplified table of genotypes. These genotypes are not publishable, since the initial sampling was biased, only marble trout (by general appearance) were sampled, so the actual percentage of non native alleles in sampled locations might differ from our results (6.6%).

Table of genotypes across 1 mitochondrial and 5 nuclear markers. Samples with non native (=brown trout alleles) are marked red and will not be used in restoration program. f - female, m - male, M - marble trout specific allele, B - brown trout specific allele.

Friday, December 5, 2008

Aquaculture paper

Another day, another paper. Sušnik et al. paper was published as a technical note in Aquaculture (2008, 285, 260-263), A set of nuclear DNA markers diagnostic for marble trout, Salmo marmoratus.

One of the main problem from the native range of marble trout is hybridisation with non native brown trout (Salmo trutta). It is not always easy to distinguish marble trout from brown trout (or from marble × brown trout hybrids) by appearance especially after a successful decade of repopulation project. Mitochondrial DNA and microsatellite markers have their limitations (maternal inheritance for the first, overlapping alleles for the later) so another set of nuclear markers was urgently needed. Markers from this paper were used exactly one year ago and that means that the 2008 results from hybrid zone will be available in a few days.

Saturday, November 22, 2008


LIFFE stands for Ljubljana International Film Festival. Four years ago we were checking the programme and saw a movie with a very fish related title. So members of the BTRG went to see Fickende Fische (Do Fish Do It?). The idea was good and worth repeating. The following year we waited too long to get the tickets so we went to see a movie with absolutely no fish related subject, Les Poupées russes (The Russian Dolls). Last year it was Sonhos de Peixe (Fish Dreams) and this year we selected a documentary Encounters at the End of the World.

4 core members of the BTRG went to see the movie plus 1 special guest star, we also met 2 former co-workers in the cinema. About the movie shot in Antarctica.... It is not a "fluffy penguin movie", more a series of interviews with "professional travellers and occasional workers", and weirdo scientists. We now understand a little bit better what people we meet on field trips think about us and our work.

Saturday, November 15, 2008

BTRG and Fisheries Institute of Slovenia have started extensive genetic analysis of brown trout across Slovenia

Native populations of brown trout in Slovenia are seriously endangered by introduced trout originating from Atlantic hatchery-reared strains.

BTRG and Fisheries Research Institute of Slovenia have started systematic screening of brown trout populations across Slovenia in order to assess the extent of “foreign blood” in native brown trout, to locate genetically pure populations and to promote an action plan for rehabilitation and preservation of native brown trout stocks.

The project is funded by the Slovenian Research Agency and the Ministry of Agriculture, Forestry and Food in the amount of 100000 €, and is being performed in a co-operation with several local angling clubs and associations across Slovenia.

Sampled fish

Thursday, November 6, 2008

Rozman et al., 2008

A paper based on Tamara's PhD thesis was just published in Animal Genetics. Two actively transcribed transferrin loci were found in both Salmo trutta and Salmo marmoratus, another evidence of ancient duplication (tetraploidization) of salmonid genome.

Preparation of metaphase chromosomes was performed in cooperation with Petr Rab's lab in Libechov, Czech Republic, fluorescent in situ hybridization was carried out at the Maribor Teaching Hospital, Slovenia.

Reprints available on request.


Monday, October 20, 2008

Introducing Gašper

Introduction of the new member of BTRG, PhD student under "Young Researcher" program, financed by the Slovenian Research Agency for the next 4.5 years:

My name is Gašper Pustovrh and I study genetics. I love to do things that involve water - like fishing, underwater fishing, free diving, etc. I graduated from veterinary medicine I already as an undergraduate student I knew I want to work with fishes. That is why I applied for a young researcher at the Chair of Genetics, Animal Biotechnology and Immunology in the Balkan trout restoration group. I am trying to find new markers that can differentiate Marble trout from Brown trout which is of great importance in preservation of the Marble trout.

new researcher

Tuesday, September 30, 2008

Field trip (sep 2008) - photos

As promised, here are pictures from Morocco. Most of pictures are by Johannes and some from Aleš's trip from 2006. Saša's camera was stolen somewhere on the way back home.


Tuesday, September 23, 2008

Field trip (sep 2008)

BTRG went to Morocco trying to get more brown trout samples for genetic analysis being performed in co-operation with Mohamed Ghamizi and Said Janjani, both from University Cadi Ayyad, Marrakech, and Patrick Berrebi. Aleš, Saša and Johannes crisscrossed the country searching mainly for brown trout from the Mediterranean drainage.

Brown trout of Atlantic lineage was recently found in Sicily, therefore populations in North Africa might represent a link to populations of Atlantic lineage in Spain. Preliminary genetic analysis of Moroccan brown trout confirmed that at least those from the Atlantic drainage appear to be closely related to brown trout from Iberian Peninsula. Previously, Bo Delling has studied Moroccan brown trout from morphological perspective, now, we intend to analyse them also from the genetic perspective.

Picture gallery will be uploaded in the next few days.

Field trip

Sunday, September 7, 2008

Workshop in La Fouly

Andrej participated in a workshop "Managing adaptive genetic variation in conservation biology" organized by the University of Lausanne in La Fouly, Switzerland, between 3-6 September 2008. Invited speakers and participants presented theoretical and practical examples of how to detect and manage traits that are under selection in a specific local environment. Andrej presented his work in progress "Establishing a brood stock of least introgressed native brown trout from admixed populations".

Some pictures from the workshop can be found here.

Wednesday, June 18, 2008


Chair of Genetics, Animal Biotechnology and Immunology (where most of the balkan-trout team works) organized the second annual picnic. There was a lot of things to celebrate: the end of the school year, Tamara's PhD, Peter's birthday and good grades received by the entire research group.

More pictures available here.


New PhD

Tamara Rozman successfully defended her PhD thesis "Characterization of transferrin locus and its application in phylogenetic analysis of genus Salmo", available here. Transferrin was the marker of choice because mitochondrial markers and microsatellites (frequently used nuclear markers) have several limitations when used in phylogenetic studies. A major problem was ancient tetraploidization of salmonid genome resulting in two actively transcribed transferrin loci.

Tamara was involved in this project for a long time, partially because of this and this reason, and also because the study was carried out on third generation of marble trout × brown trout hybrids (generation time 2-3 years).

Tamara in action

Thursday, June 12, 2008

Vrljika paper

Vrljika softmouth trout paper was just published. Overview here.

Softmouth trout from Vrljika

Thursday, May 22, 2008

Plans for this summer

Summer - no students, too hot for latex gloves, low water level, fish have nowhere to hide. Time to get as many fin clips as possible. Expect pictures in early August and late September.

(Peter provided the guidebook scennery. And a drink for the photographer.)

Planning field trips

Wednesday, May 14, 2008

Young researchers

Public Tender for Early Stage Research Candidates for the Year 2008 is out (available in Slovenian and English). Those who are interested can join our group under the mentorship of Simona Sušnik.

Criteria in details and how to apply are here, briefly:

  • Bachelors degree and average grade >8.00 or
  • Completed second degree according to the Bologna process and average >8.00 or
  • Masters degree of science
  • Maximal age 28 years (born 1980 or after)

Duration of founding:

  • 4.5 years (for 4 year doctoral study course)
  • 3.5 years (for third level study according to the Bologna process)

Tuesday, April 29, 2008

Beyond trout

As of recently, we are interested in more than salmonids. More about it when we publish something. For now, here are teasers from 2 non salmonid projects.



Wednesday, April 16, 2008

Guess the trout

How to identify the species? Is it possible to tell by color/shape/general appearence (phenotype) which trout is brown trout (stocked Atlantic lineage, native Adriatic lineage), dentex trout, softmouth trout, marble trout or hybrid?

This question is common in internet forums. In short, the answer in most cases is no. But here is a challenge, try to identify trouts on the picture below. Write your answers in comments, wait for the results of genetic analysis.

All fish were caught in the River Neretva, where we already found several trout species, you can also choose from this list.


Wednesday, April 9, 2008

Child play

Playing with Legos at work - a dream job. Several educational DNA sets were selected and tests are underway to choose the appropriate one for students.


Human genetics

Sooner or later, one needs to have a good negative or positive control when working with delicate (as the opposite of optimised) protocols. Human DNA seems like a good option and it works great for training purposes. For example, Y chromosome was proven for 2 lab researchers, for a good salmonid karyogram one needs some magic luck. And so when one researcher was isolating DNA from the same two blood samples for the third time, a dozen of his colleagues volunteered. Universality of some mtDNA primers will also be tested.

Control DNA

Friday, March 21, 2008

Some kind of order

There is an inexplicable urge in biology to sort, classify and order. The whole fish business grew over the last few years and so did the number of DNA isolates, primers, fin clips, blood samples and a mountain of working solutions. The time has come to sort them. A database of fish primers was created, stock solutions are now neatly packed in 4 boxes. DNA isolates and fin clips will follow.


Sunday, March 16, 2008

Sir Humphry Davy

I read something about Humphry Davy on the BBC News website today. His name appeared on Slovenian TV a few years ago, apparently he was in Podkoren and Ljubljana several times, fly fishing. He even wrote a book "Salmonia or Days of Fly Fishing" (full content), published in 1832. In it, variability of salmonids, over fishing, stocking non native fish and taxonomic problems are mentioned beside personal experience of fly fishing in Great Britain, Ireland, Illyria (more or less present day Slovenia) and in several locations in Austria. Salmon, brown trout, huchen, grayling and charr are discussed, no mention of marble, softmouth or dentex trout.

Sunday, March 9, 2008

A new piece of equipment II

As mentioned, a younger and better looking model appeared to present the wonderful new ABI3130xl.

16 capillary system

Tuesday, March 4, 2008

Bilateral cooperation

Saša of the University of Belgrade has joined us in the laboratory for 2 weeks. He is a regular participant at sampling field trips and is the author or coauthor of several papers, mostly on the subject of salmonids of Serbia. His visit was made possible by a bilateral agreement between Slovenia and Serbia promoting scientific cooperation. We got a 2 year grant for our fish project and now we have to spend the money. These two weeks were very busy, he analysed a ton of samples, but we did find some time to enjoy the winter sun.

Working in the laboratory

Tuesday, February 5, 2008

Update during Carneval season

Our site has some new pages. We have added information for potential undergraduate and PhD students that would like to join us. Most photos on our site is from sampling expeditions, therefore a lot of photos from laboratories and offices of our department were added to the new pages to show a more realistic view of our everyday work.

Genomic DNA isolation

During the 2000th visitor party (see previous post) we had a lot of great ideas, some of them have now materialised. Services (genotyping of trout and grayling), some marble trout updates and photos from Zeta field trip. Several pages are now available in both English and Slovenian.

Aquarium trick

Thursday, January 24, 2008


BTRG celebrated the 2000th visitor of our website in a Bosnian restaurant. Special guest star was of course David, the designer of Frequent site visitors already know his lovely wife Tamara.

site designer

Friday, January 18, 2008

Marble trout

A new fish taxon was added to the balkan-trout site.

Marble trout (Salmo marmoratus) is native to the North Adriatic river systems (e.g. the Po river system in Italy and the Soča/Isonzo river system in Slovenia and Italy) and is one of the most endangered freshwater species. The main threat has been hybridization with introduced brown trout. Dr. Meta Povž from Fisheries Research Institute of Slovenia, French researchers Dr. Alain Crivelli and Dr. Patrick Berrebi and Dušan Jesenšek, the manager of Tolmin fish farm of the Angling Club of Tolmin are just a few of people involved in an action plan for marble trout restoration, which was initiated in 1992 and later joint also by the Department of Animal Science at the University of Ljubljana.

Read more about it in Studied taxa.

Salmo marmoratus

Monday, January 7, 2008

Website report for 2007

The traffic on our website is monitored by StatCounter and Google. Both have several limitations, but we can get a decent picture of what our visitors are looking for and where they came from. Most of the last 500 visitors (68.71%) were not from Slovenia, which is one of the reasons why the site currently exists in English version only. Last 500 visitors were from:

31.29% Slovenia
11.06% United States
7.29% Serbia And Montenegro
6.82% Italy
5.18% Austria
4.47% Croatia
4.00% Bosnia And Herzegovina
4.00% Sweden
3.76% Russian Federation
3.53% United Kingdom
2.35% Japan
1.88% Bermuda
1.65% Czech Republic
1.65% France
1.41% Denmark

One of the limitations is the inability of StatCounter to distinguish properly visitors from Serbia and from Montenegro, sometimes placing them in "unknown" or third countries. A lot of visitors came from internet forums, Patagonia websites and from Google search results. Google search queries that returned pages from our site and were clicked in the last 3 months of 2007 were:

26% balkan trout
7% softmouth trout in croatia
6% potočna pastrmka rijeke bune
4% atlantski losos
4% lososu podobna sladkovodna riba
4% sasa maric
4% world distribution of brown trout
3% biolog sasa maric
3% radovanjska reka
2% balkan razpet
2% golema reka pastrmka
2% neretva
2% rečna pastrmka
2% salmo trutta marmoratus
2% soft mouth trout
2% softmouth trout
2% zubatak
2% berrebi patrick
2% egejski recen sliv na makedonija
2% geneticka varijabilnost prirodnih populacija metode procene
2% geologija cetina
2% koje reke pripadaju jadranskom slivu
2% mesinska kriza saliniteta
2% ogrožena soška postrv
2% recni pritoki vo makedonija
2% sadasnji i perspective vidovi koriscenja reke u pirotu
2% salmo marmoratus
2% steven weiss slovenia
2% zubatak iz krke

One of the reasons why our site was named Balkan Trout is that it is easy to remember.