New publication

A paper describing a new nDNA-based method for discriminating Salmo sp. purebreds from hybrids has been just published in Aquaculture. The method, which is based on KASPar technology, is especially important for marble trout conservation.

Staff changes and other important events

Anja defended her PhD thesis in April, 2012, “Molecular ecology of imotska gaovica (Delminichthys adspersus (Heckel, 1843))”, a minnow-like fish, endemic to karstic environment of the Western Balkans. They are found only in springs and associated subterranean waters. In many locations, gene flow is maintained across geographically separated populations despite the absence of superficial interconnections of those waterways. Anja concluded that the only apparent explanation for this is subterranean migration of the fish between populations, a phenomenon never before documented in epigenic fishes.

A part of her work was published in Molecular Ecology, and the picture of the studied fish, taken by Arne Hodalič, appeared as the cover image of the journal.


Two others publications came out as a result of this study, one in Journal of Biochemical Systematics and Ecology and one in Ecohydrology.

She just left afterwards.

One day, two papers

BTRG had a lucky day: two papers were published on the same day.

A short paper about brown trout was published in Croatian journal. Unlike most of our research on brown trout, this paper is not about wild population. We genotyped fish from Fishing Club Bled fish farm to estimate the level of introgression of non native (Atlantic) genetic markers into native (Danubian) brown trout. Introgression was higher in females, probably because survival rate of males in captivity is lower therefore new males are routinely transferred from the wild where introgression is lower.

The second paper is about huchen, an endangered salmonid that matures at 65-70 cm of length and is endemic to the Danube basin. Unlike the highly diverse brown trout, huchen has low genetic variability so even fish from distant locations are genetically very similar. Based on observed markers, samples from 6 countries can be placed into two clusters: Austria / Slovenia and Ukraine / Slovakia / Montenegro / Bosnia-Herzegovina.

There are several possible explanations for low diversity within the species: (1) a slow molecular clock - essentially slow evolution; (2) low historical effective population sizes - small number of "breeders" in the entire basin; (3) a speciation founder effect - all living huchens are descendants of a very small number of ancestral huchens; (4) more recent human-caused bottlenecks - caused by overfishing and habitat degradation.

Dentex paper

Dentex paper was published. Finnaly. The results were mentioned before, samples from Montenegro were included in the final version.

Neretva and Skadar basins are inhabited by a complex mixture of salmonids of different appearances and sometimes of similar appearances and different genetic characteristics, which is why we are working on them in the first place. Results are often difficult to publish because of "small sample size" or because the studied taxa are "only of local significance". Dentex paper was one of the most difficult papers so far, because Aleš wanted to put it into a journal where we have no previous publications and because we did submit it to journals where our chances were statistically insignificant. Here is the list of attempted paper submittions:

• Freshwater Biology
  6 Apr 2009
  I regret that the advice I have received is that your paper is of insufficient general interest for Freshwater Biology and that it should be submitted to a more specialised fish journal.
• Nature
  30 Apr 2009
  ...after consideration, we are not persuaded that your findings represent a sufficiently outstanding scientific advance to justify publication in Nature.
• Biological Journal of the Linnean Society
  11 Jun 2009
  The Journal has a large backlog of high quality papers awaiting publication and because of this I am forced to adopt a stringent editorial policy. As a result I can accept only papers that are strongly recommended by all referees.
• Canadian Journal of Fisheries & Aquatic Sciences
  24 Dec 2009
  ...given that it is somewhat specialised in its subject matter, we recommend that it would be better suited to a more specialised journal such as Molecular Ecology or Copeia.
• Zoological Journal of the Linnean Society
  5 Jan 2010
  The ZJLS is dedicated to systematic, phylogenetic and evolutionary zoology, but the main emphasis of this paper is a population genetic study of a single taxon.
• Hydrobiologia
  4 May 2010
  We are pleased to inform you that your manuscript, "Resolving taxonomic uncertainties using molecular systematics: Salmo dentex and the Balkan trout community", has been accepted for publication in Hydrobiologia

We will remember John's submittion in Nature as the rejection arrived in his mailbox in about half an hour. This is apparently called "the Nature rodeo". Hydrobiologia reviewers had about 90% of very relevant issues, but of course there was the standard "Reviewer #2: The English needs to be improved". The same happened even when we had 2 native English speakers as co-authors.

In other news

Dentex paper was accepted after several failed attempts, we will all remember the Nature roller coaster experience. More details about this paper in the near future, the title is "Resolving taxonomic uncertainties using molecular systematics: Salmo dentex and the Balkan trout community", authors are Aleš Snoj, Branko Glamuzina, Andrej Razpet, John Zablocki, Ivan Bogut, Estelle Lerceteau-Köhler, Naris Pojskić and Simona Sušnik.

National Geographic paper (in Slovenian) is now available.

After spending the last few years working with students, Karst shepherds, Carniolan honey bees and cattle, Andrej has started with his basic postdoc project Immune response and behaviour of domesticated and wild brown trout financed by the Slovenian Research Agency for the next 2 years.

Intermediate report

As mentioned before, 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.

An intermediate report was just published in the Ribič journal (in Slovenian). Essentially, members of local fishing societies and Fisheries Research Institute of Slovenia provided fin clip samples for our group, Gašper participated in several sampling expeditions and Klavdija did most of the work in the laboratory. 1070 samples from 44 locations were analysed, 4 putatively genetically pure populations of brown trout were found, 40 populations show various degrees of hybridization with domesticated strain of brown trout (Atlantic lineage).

The search for more genetically pure populations that could be used for restoration of native brown trout in hybridized populations continues.

National Geographic

Cooperation with Arne has produced a paper in Slovenian edition of National Geographic about marble trout from Slovenia and Softmouth trout from Herzegovina (The River Vrljika). We have the permission to put the paper on our site at the end of April, but until then only abstract is available (in Slovenian).

Softmouth trout from Vrljika

Several field trips and a lot of work was done near Imotski in Croatia. Softmouth trout was perhaps the most interesting fish from that area. Aleš has published a paper in Športski ribolov (Sport Fishing), presenting genetic results to the wider public. Special thanks to Daliborka Dušanić for translation to Croatian.

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.

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.

Vrljika paper

Vrljika softmouth trout paper was just published. Overview here.

Native and genetically pure brown trout of the Danubian drainage

A paper by Andrej & Aleš was published in "Ribič", Journal of the Association of Slovenian Fishermen (not the official English name of the organization).

This paper was a response to several papers in the Ribič journal where genetically pure and /or native brown trout were mentioned. Problematics of hybridization with non native brown trout was presented as well as published and unpublished results of our surveys in several Slovenian rivers.

It is worth to mention that Kottelat and Freyhof in their "Handbook of European Freshwater Fishes" (2007) use the almost forgotten name Salmo labrax for native brown trout of the Danubian drainage.

Lake Ohrid trouts

A paper by Simona was published in "Ribič", Journal of the Association of Slovenian Fishermen (not the official English name of the organization).

Two less known salmonid fishes (Salmo ohridanus and Salmo letnica) from Lake Ohrid (Macedonia) were presented to the Slovenian public. A more detailed science paper was already published in Journal of Fish Biology.