Event Abstract

Does Loire grayling represent a distinct species ?

  • 1 Société Française d'Ichtyologie, France
  • 2 Muséum national d'Histoire naturelle UMS PatriNat 2006 (MNHN - AFB - CNRS) Equipe "Connaissance Espèce" 43 rue Cuvier CP26 75005 Paris, France, France
  • 3 CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal
  • 4 Departament of Biology, Faculty of Sciences, University of Porto, Portugal
  • 5 University of Graz, Institute of Biology, Universitätsplatz 2, A-8010 Graz, Austria, Azerbaijan

The application of molecular-based approaches to evaluate the diversity of freshwater fishes has helped promote a greater recognition for the diversity. Accordingly, the number of recognized species has been steadily increasing over the past two decades. The salmonid genus Thymallus (grayling) has been no exception to this trend, whereby some of the now 14-18 listed species are found in Asia distributed across the extensive catchments of the Amur, Lena, Enisey and Ob river systems (Antonov & Knizhin, 2014; Dyldin et al. 2017). In Europe, aside from the nominal European grayling (Thymallus thymallus) only grayling of the Adriatic basin T. aeliani (Valenciennes 1848) (Bravnickar et al. 2015) have been proposed as representing a distinct taxon. Herein we discuss the status of the Loire grayling, living at the westernmost distribution range of European grayling. Various genetic markers (including allozymes, µSats and mtDNA gene sequences) underscore a level of homogeneity of grayling within the Loire basin, and a relatively distinct divergence from all other European populations. Additionally, grayling from the adjacent Rhone catchment are not closely related to Loire grayling underscoring a long period of isolation, with no indication of spread into the Loire drainage during one of the last glacial or interglacial periods. Consequently, the arrival of grayling in the Loire catchment is probably rather ancient, even if its present low intra-catchment diversity suggests a rather recent bottleneck. This bottleneck may have been caused by a very hot period during one of the last interglacials, and that may also be the reason why grayling did not historically inhabit the Seine catchment (lower altitudes). However, grayling now occurs there through successful introductions several decades ago (there is also not archaeological evidence of historic occurrence there, by contrast with the Loire where it is known in pre-historical remains). A potentially significant fact in considering the distinctiveness of Loire grayling is that the lineage seems able to outcompete the numerous introductions of foreign lineages carried out in attempts to supplement or sustain local populations with hatchery material (Persat et al. 2016). Elsewhere in Europe, such as the Soca River in Slovenia, native stocks have been easily introgressed with hatchery introduced stocks. We review here the data on the distinctiveness of Loire grayling, including morphological traits, color patterns, genetic characteristics and viability in native or introduced habitats.

Acknowledgements

This work developed at the Universities of Lyon (UMR 5023) and Graz (Institut für Biologie), and MNHN Paris has been supported and funded by many national French partners (CSP, ONEMA, AFB, FNPF, EDF) and a dozen of French Departmental Angling Federations. It has also been supported by the Swiss OFEV.

References

Antonov, A.L., Knizhin, I.B., 2014: Graylings (Thymallidae) of the Amur River basin: history of research and modern concepts of diversity. Amurian Zoological Journal 6 (3): 298–307. [In Russian]. Bravničar J., Palandačić A., Susnik Bajec S. & Snoj A., 2015 : Genetic introgression insights in Adriatic grayling (Thymallus thymallus aeliani) obtained from museum specimens. In: 2nd International Workshop on Conservation Biology. 17–19 June 2015. UP FAMNIT, Koper, Slovenia. Dyldin et al. 2017 : Review of the Thymallus genus (Pisces: Salmoniformes, Salmonidae, Thymallinae) with taxonomic comments. Bulletin Lampetra VIII: 103-126. Persat H., Mattersdorfer K., Charlat S., Schenekar T., Weiss S., 2016 : Genetic integrity of the European grayling (Thymallus thymallus) populations within the Vienne River drainage basin after five decades of stockings. Cybium, 40(1), 7-20.

Keywords: Loire basin, Grayling, biogeography, morphology, Taxonomy

Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019.

Presentation Type: Oral

Topic: GRAYLING (GENUS THYMALLUS): EVOLUTION, SYSTEMATICS, MANAGEMENT AND CONSERVATION

Citation: PERSAT H, Denys GP, Froufe E, Secci-Petretto G and Weiss SJ (2019). Does Loire grayling represent a distinct species ?. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00070

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Received: 19 Jun 2019; Published Online: 14 Aug 2019.

* Correspondence: Dr. Henri PERSAT, Société Française d'Ichtyologie, Paris, France, grayling@laposte.net