Genetic evaluation of the self-sustaining status of a population of the endangered Danube salmon, Hucho hucho

Abstract

A new multiplex microsatellite protocol was developed for population screening of the endangered Danube salmon (or huchen) Hucho hucho. Allelic variation was screened at five newly cloned and four previously published loci in 246 samples to help evaluate the self-sustaining status of an urban population of huchen in the framework of a controversial environmental assessment in the Mur River, Austria. The loci revealed 78 alleles (mean = 8.6), and in the Mur River an average expected heterozygosity of 0.668. We inferred that the huchen population in and around the city of Graz is self-sustaining based on the following evidence, which includes both genetic and non-genetic sources of information: (1) there is little to no current stocking; (2) presence of juvenile huchen in multiple year classes; (3) sighting of spawning events; (4) documentation of 14 spawning redds; (5) no deviation from Hardy-Weinberg equilibrium; and (6) limited number of recaptures or parental matches with presumed parent fish of stocking operations. We discuss the potential application of such an analysis in evaluating threatened huchen populations throughout their native distribution.

Conservation genetics study of huchen in Slovenia recommends river system‐based management and indicates self‐sustainability of the middle Sava population

“…Here, the greatest genetic diversity was observed, apparently because of interbreeding between local and stocked huchen, and the relatively large population size of huchen in this stretch of river, which we estimated to harbour approximately 300 sexually mature individuals. This level of genetic diversity is comparable to the values reported for admixed huchen from the upper Danube in Germany and the Mura in Austria (Geist et al, 2009; Weiss & Schenekar, 2016).…”

“…DNA was extracted from fin tissue following the high‐salt extraction protocol of Miller, Dykes & Polesky (1988). Population screening was performed using a suite of 12 microsatellite loci, of which nine had been previously reported as informative for huchen (Weiss & Schenekar, 2016; Table 2), while the other three had been developed for brown trout ( Salmo trutta ) by Schenekar, Lerceteau‐Koehler & Weiss (2014) and proved polymorphic for Slovenian populations of huchen in unpublished preliminary screening (Table 2). All the reactions were carried out in multiplexes using the Type‐It Microsatellite PCR Kit (Qiagen) following the manufacturer's instructions (Table 2).…”

Seasonal variation of blood biomarkers in huchen, Hucho hucho (Actinopterygii: Salmoniformes: Salmonidae) reared in captivity

“…This species is listed as endangered by the IUCN Red List (Freyhof and Kottelat 2008). The limited habitat of huchen populations has led to a reduction in their abundances and consequently to genetic drift within populations (Weiss and Schenekar 2016).…”

Original article Target cell type dependent immune activity of plant extracts in bovine raised under different technologies

“…The endangered Danube salmon, Hucho hucho (Linnaeus, 1758), or huchen as well-known in Central and South-Eastern Europe, represents the flagship of the Salmonidae family (Weiss and Schenekar, 2016). Until recent times, the species was present in the Danube River and most of its mountain and submontane tributaries (Formicki et al, 2013).…”

“…Today, the species occupies only about a quarter of its original range in Europe, mainly due to river regulation, dam and reservoir construction, major water consumption by industry and agriculture, river pollution and accelerated eutrophication (Holcik et al, 1988;Holcik, 1990;Formicki et al, 2013). The species is endangered (EN) according to IUCN (International Union for Conservation of Nature) (Freyhoff and Kottelat, 2008) and listed under Annexes II and V of the European Habitat Directive, as well as Appendix III of the Bern Convention of European Wildlife and Natural Habitats (Weiss and Schenekar, 2016). The huchen is also reported in Annexes II (designated as Sites of Community Importance must be protected under the Natura 2000 Network and the sites managed in accordance with the ecological requirements of the species) and V of the EU Habitat Directive (Ihut et al, 2014).…”