GENETIC STRUCTURE
OF HUCHEN (Hucho hucho)
ASSESSED USING mtDNA
(CONTROL REGION AND NADH1 GENES)
AND TWO MICROSATELLITE LOCI
AND FISHERIES MANAGEMENT WITH
HUCHEN STOCK IN SERBIA
Predrag SIMONOVIĆ, Ana TOŠIĆ,
Dubravka Škraba & Vera NIKOLIĆ
GENERAL FEATURES OF HUCHEN-DANUBE SALMON
Huchen are endemic for the River Danube basin (Holčik,
1990).
• Live in rivers and large streams
• Can live in lakes and large reservoirs
• At altitude 200 – 600 m, and out of it if life conditions are
suitable:
• cold water, usually up to 15oC
• sufficient amount of dissolved oxygen (8 – 9 mg l-1).
However, in contrast to other salmonid fish, huchen tolerate
the water temperature up to 22oC and the amount of dissolved
oxygen down to 5 mg l-1 (Holčik et al., 1988).
THREATENING FACTORS
Recently, huchen endures in about 33% of its former
dispersal area
Formerly continuous area inhabited by the huchen is
now disrupted into isolated submountain zones of
rivers, mainly due to:
• increased streams’ embankment construction,
• damming of rivers,
• industrial and agricultural pollution,
• heating due to deforestation,
• eutrophication
• poaching
Translocations of huchen among river drainages
undoubtedly threaten aboriginality of huchen
populations.
Therefore, since 1990:
on the IUCN Red List of Threatened species:
• EN – Endangered B2ab(ii,iii),
• in the Appendix III of the Bern Convention (Protected
Fauna) and
• Annexes II and IV of the EU Habitat Directive (IUCN, 2008).
In contrast to their conservation status and due to their great
attractiveness for angling and financial benefit contributing to
the local rural communities, huchen is allowed for angling,
following the:
1. closed season for huchen fishing (1 March – 31 August)*,
2. daily fishing time limitation (daylight, from dawn to dusk)*
3. minimal landing size (100 cm SL) proscribed*
*Anonymous
(2009). Order on measures for conservation and protection of fish
stocks. Off. Gazzette of the Rep. Serbia, 104/09.
The minimal landing size was proscribed in 2003 (Anonymous, 2009) after
the investigation of adult huchen growth characteristics (Simonović et al.,
2000).
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5
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6
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Meanwhile, an analysis accomplished on huchen from the Drina River in the
last three years revealed lower values both for length and mass at wich adult
huchen alter their growth (Simonović et al., 2011).
Simonović, P., Marić, S. & Nikolić, V. (2000). Growth characteristics of huchen Hucho hucho (L.) from Rivers
Drina, Una and Sana. Acta Biologica Iugoslavica – Ekologija Belgrade 35: 123-126.
Simonović, P.D., Nikolić, V.P., Tošić, A.D. & S.P. Marić (2011). Length-weight relationship in adult huchen Hucho
hucho (L., 1758) from Drina River, Serbia. Biologia, Bratislava Section Zoology 66/1: 156-159, DOI:
10.2478/s11756-010-0135-2.
14 huchen samples from six locations in Serbia were collected by
electrofishing and angling from 2002 until 2007 (Fig 1). Fin clips were taken
and stored in 96% ethanol and two mtDNA genes, CR and NADH1, were
amplified in 14 individuals using polymerase chain reactions (PCR).
Sequencing of two mtDNA genes (Control Region, 834 bp with addition of 8-10
repetitions of 82 bp each, and NADH-1, 811 bp) revealed the same haplotypes
(CR_1 and ND_1) in all investigated specimens, i.e., the complete lack of genetic
variability.
Sequence of control region (haplotype CR_1) of huchen from Serbia (unpublished)
ACCCTCTGGCGCCAATGTACAATAATAAATGTTATATCTTACAAGTCAGTACGATATAACACTTATGTATTATATTACATATTATGTATT
TACCCATATATAATATTGCACGTGAGTAGTACATTATATGTATTATCAACATAAGTGGTTTCAACCCCTCATACATCAGCACAAATCCAA
GGTTTACATTAAGCAAAACACGGATAACCACCAACTAAGATGTTTTAACCTGATTAATTGCTACACCACAAACCTTCAGCTAACACGAG
CTCCGTCTTTACCCACCAACTTTCAGCATCGGTCCTGCTTCATGTAGTAAGAACCGACCAACGATTTATCAGTAGGCATACTCTTATTGA
TGGTCAGGGGCAGAAATCGTATTAGGTAGCATCTCGTGAATTATTCCTGGCATTTGGTTCCTATATCAAGGGCTATCCTTAAGAAACCA
GCCCCTGAAAGCCGAATGTAATGCATCTGGTTAATGGTGTCAATCTTATTGCCCGTTACCCACCAAGCCGGGCGTTCTCTTATATGCATA
GGGTTCTCTTTTTTTTTTTTTCCTTTCAGCTTGCATATACAAGTGCAAGCAAAGAAGTCTAACAAGGTCGAACTAGATCTTGAATTCCAG
AGAACTAATGTATCATTATAGAATGATATTTTATAAAGAACCACATACTTGGATATCAAGTGCATAAGGTCCAATTCCATCCTCACAGA
TATCTAATAGATCCCCGGCTTCTGCGCGACAAACCCCCCTACCCCCCTACGCTGAACGATCCTTGTGTTCCTGTCAAACCCCTAAACCAG
GAAGTCTCAACAGCGCTAATTTTTGTT
Sequence of NADH-1 gen (haplotype ND_1) of huchen from Serbia (unpublished)
ATGACTACCCTTATCACCCATGTTATTAACCCACTCGTATACATTGTGCCTGTTCTCCTAGCAGTTGCTTTCCTCACCCTCCTCGAACGAAA
AGTTCTCGGGTACATGCAACTTCGAAAGGGACCTAATATTGTTGGTCCATATGGGTTACTTCAACCCATTGCAGACGGCCTTAAGCTATTT
ATTAAAGAGCCAGTTCGACCATCCACCTCTTCCCCCTTCCTATTTCTTGCCACACCAATACTTGCCTTAACACTTGCACTCACTTTATGAGC
CCCCATACCAATCCCCTACCCCGTTACAGACCTAAACCTAGGGGTATTATTTGTCCTGGCACTCTCTAGCCTCGCTGTGTACTCTATTTTA
GGTTCAGGATGAGCTTCAAATTCCAAATATGCCTTAATCGGAGCCCTACGAGCAGTAGCACAAACTATTTCCTATGAAGTCAGCCTAGGC
CTAATCTTACTAAGCGTGATTATTTTTACAGGCGGATTCACACTCCAAACCTTCAACGTTGCTCAAGAAAGTATCTGACTACTTGTACCAG
CCTGACCCCTTGCCGCCATATGATACATCTCAACCCTAGCTGAGACAAACCGTGCACCATTTGACCTCACAGAAGGAGAATCAGAATTAG
TCTCCGGATTTAATGTAGAATATGCTGGGGGACCCTTCGCCCTTTTTTTCTTAGCCGAATACGCTAATATCCTTCTAATAAATACACTCTC
AGCCATCCTATTCCTGGGCGCATCCCATATCCCAACTCTCCCTGAACTAACAGCCCTTAATCTCATAACAAAAGCTGCCCTAC
Explanation for the lack of variability:
• Small investigated territory
• Small number of drainage areas
• Small number of samples
• Small number of genes, their location and specificity
Result of analysis of genetic structure in huchen using the
mtDNA are preliminary.
Since mtDNA:
• is inherited almost exclusively from mother’s side
• is selectivelly neutral
it is not a good indicator of relationships between
populations.
An evolution of one gene can differ from an average
evolution of whole genom (Zhang & Hewitt, 2003; Boero
2010). Therefore, the use of mtDNA as a genetic marker can
be misleading.
Zhang D.-X., Hewitt G. M. 2003. Nuclear DNA analyses in genetic studies of populations: practice,
problems and prospects. Molecular Ecology 12: 563-584
Boero, F. (2010). The study of species in the era of biodiversity: A tale of stupidity. Diversity 2010
(2): 115-126, doi:10.3390/d2010115
The analysis that included two microsatelite markers on more
numerous samples from larger territory gave more reliable
insight into genetic differentiation of huchen, since three unique
alleles (336, 356 &360) were found at the HLJZ003 locus in
huchen at the territory of Serbia (Drina and Ibar Rivers).*
It revealed the large scale of huchen populations’ structuring
(Western: Austria + Slovenia; Eastern: Serbia + E Bosnia +
Montenegro; Slovakia + Ukraine), indicating that stocking
between the adjacent drainages within the Danube River
catchment must be stopped, if the aboriginality of huchen stocks
is to be retained.
Even the mtDNA on that large geographic scale revealed two CR
and four NADH-1 haplotypes, which additionally supports the
strong recommendation for avoiding the stocking with huchen
out of the native drainage area.
•
•
Weiss, S., Marić, S. & Snoj, A. (2011). Regional structure despite limited mtDNA sequence diversity found in the
endangered Huchen, Hucho hucho (Linnaeus, 1758). Hydrobiologia (2011) 658:103–110
Marić, S., Razpet, A., Nikolić, V., Snoj, A. & Simonović, P. (2012). Genetic diversity of huchen (Hucho hucho ) in
Serbia. II International Hucho Symposium – Lopuszna, Poland, September 19 – 22, 2012. Book of Abstracts, 3536.
MANAGEMENT RELEVANCES
•Before the 2000, it was detected that growth of huchen from the Drina River
altered at 16.5 kg and 110 cm Sl,
•In the last three years the recorded values were 10.5 kg and about 98 cm Sl.
•Indicates to changes in life-history characteristics of huchen, probably the
drop in fecundity, i.e., in reproductive effort of adult huchen.
•The coincidence between decrease in size and in fecundity might reflect the
change in population structure of huchen from the Drina River.
•Unfortunately, the records are so far too sparse for inferring on the character
of that change.
•The frequency of fish lengths in available landing records in 2007 – 2008
period (Marić et al. 2009) warrants that small decrease in landing size in
relevance to the results of investigation would not remarkably increase the rate
of landing.
•Therefore, it was recommended to the fishery administrative authority to
decrease the minimal landing size from 110 cm (Anonymous 2003) to 100 cm
SL.
The only available records about the huchen production are those from
the Fisheries Management Plan for the Drina River, assessed in 2003.
• Section Bajina Bašta held biomass of 27 kg km-1 (12.65% of the total
standing fish community), which yielded annual natural production of
23.077 kg km-1.
• Section Ljubovija held biomass of 34.511 kg km-1 (10.84% of the total
standing fish community), with the annual natural production of
24.000 kg km-1.
Having in mind that total estimated fish biomass in the Bajina Bašta
section in 2003 was 212.852 kg km-1 and in the Ljubovija section it was
318.211 kg km-1, comprising associating fish species common in
the huchen’s ecosystem (e.g., grayling, nase, chub, Danubian roach,
barbel, brook barbel, schneider and bullhead), it is clear that those
sections of the Drina River were favorable for the production of huchen
with the
• sufficient food availability
• sufficient ecosystem integrity
• sufficient water quality
Main adverse effect is the lack of consistent spawning sites, due to
the fluctuation in water level caused by hydropower plant “Perućac” in
the spawning period, which either dries out redds situated usually inshore
in the main river bed, disrupts the way into the inlets of spawning
tributaries, or does both of harms for spawning huchen.
HUCHEN STOCK MANAGEMENT ACTIVITIES
• complies with the recommendations in the Precautionary
Principle
• add to an improvement of the recent conservation status of
huchen
• enable fisheries utilization through an opportunity to catch
and play the largest World’s salmonid
• provide a remarkable component of developmental force for
the local rural communities
That point of view, however, was neglected by fishery
management authority, who narrowed in 2009 (Anonymous
2009) the huchen fishing season for three months by excluding
the whole summer from it, despite of that might decrease the
incomes of fishery managers and their capability to cope with
the still frequent practice of nocturnal summer huchen
poaching in field.
ARTIFICIAL SPAWNING AND REARING FOR STOCKING
PURPOSES
Hitherto, there were two stocking occasions with huchen in last
ten years, both with the brood fish taken from the Drina River.
• The first one was acconmplished in 2000 and yielded about 104
yearlings which were stocked to the Rivers Drina and Lim and
introduced for the first time into the River Djetinja*.
• The second one was accomplished in 2012 and yielded about 103
yearlings stocked into the Drina River.
Mijović-Magdić, J. i Hegediš, A. (2000). Savremeni status mladice (Hucho hucho) u vodama Srbije i mogućnost kontrolisanog mresta i
gajenja mlađi u uslovima intenzivne ribnjačke proizvodnje. «savremeno ribarstvo Jugoslavije» - Vršac, 20. – 22.septembar 2000.
Zbornik sa IV Jugoslovenskog simpozijuma «Ribarstvo Jugoslavije»: 75-80.
In addition, poaching and river bed regulation made also harms
for huchen stocks.
In catchments of other rivers and streams in Serbia (Lim, Uvac
and Vapa, Ibar and Djetinja, where huchen were introduced
from the Drina River), data about the huchen stocks are very
limited.
Regardless the state authorities have adopted the Action Plan for
Management with Huchen Stocks in Serbia*, implementation of
activities and measures it recommended is very narrow and
limited.
Hegediš, A., Mićković, B. & Cvijanović, G. (2005). Akcioni plan upravljanja mladicom u ribolovnim vodama
Republlike Srbije. Centar za multidisciplinarne studije Univerziteta u beogradu, 52 pp.
Thank you for your attention
and have a nice day!