Phylogeography, genetic structure, and conservation of the endangered Caspian brown trout, Salmo trutta caspius (Kessler, 1877), from Iran
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The Caspian Sea, the largest inland closed water body in the world, has numerous endemic species. The Caspian brown trout (Salmo trutta caspius) is considered as endangered according to IUCN criteria. Information on phylogeography and genetic structure is crucial for appropriate management of genetic resources. In spite of the huge number of studies carried out in the Salmo trutta species complex across its distribution range, very few data are available on these issues for S. trutta within the Caspian Sea. Mitochondrial (mtDNA control region) and nuclear (major ribosomal DNA internal transcribed spacer 1, ITS-1, and ten microsatellite loci) molecular markers were used to study the phylogeography, genetic structure, and current captive breeding strategies for reinforcement of Caspian trout in North Iranian rivers. Our results confirmed the presence of Salmo trutta caspius in this region. Phylogenetic analysis demonstrated its membership to the brown trout Danubian (DA) lineage. Genetic diversity of Caspian brown trout in Iranian Rivers is comparable to the levels usually observed in sustainable anadromous European brown trout populations. Microsatellite data suggested two main clusters connected by gene flow among river basins likely by anadromous fish. No genetic differences were detected between the hatchery sample and the remaining wild populations. While the current hatchery program has not produced detectable genetic changes in the wild populations, conservation strategies prioritizing habitat improvement and recovering natural spawning areas for enhancing wild populations are emphasized.
KeywordsSalmo trutta caspius Genetic population structure Phylogeography Conservation Caspian Sea
We would like to express our gratitude to the manager and staffs of Kelardasht Culture and Breeding Centre of Salmonids, Iran for providing the fish. We thank L. Insua, M. Portela, S. Sánchez, M. López, S. Gómez, M. Otero, and Z. Ghasemi for technical assistance. This research was supported by funding from University of Santiago de Compostela (Spain) and University of Tarbiat Modares (Iran).
- Abdoli, A., 2000. Inland Water Fishes of Iran, 1st ed. Iranian Museum of Nature and Wild Life, Tehran.Google Scholar
- Coad, B. W., 2000. Criteria for assessing the conservation status of taxa (as applied to Iranian freshwater fishes). Biologia 55: 537–555.Google Scholar
- Goudet, J., 2001. FSTAT, a program to estimate and test gene diversities and fixation indices (version 2.9.3) [available from http://www.unil.ch/izea/softwares/fstat.html].
- Hansen, M. M., D. E. Ruzzante, E. E. Nielsen, D. Bekkevold & K. L. D. Mensberg, 2002. Long-term effective population sizes, temporal stability of genetic composition and potential for local adaptation in anadromous brown trout (Salmo trutta) populations. Molecular Ecology 11: 2523–2535.PubMedCrossRefGoogle Scholar
- Harley, E. H., 2001. AGARst. A program for calculating allele frequencies, GST and RST from microsatellite data. University of Cape Town, South Africa.Google Scholar
- Kiabi, B. H., A. Abdoli & M. Naderi, 1999. Status of the fish fauna in the South Caspian basin of Iran. Journal of Zoology in the Middle East 18: 57–65.Google Scholar
- Laikre, L., A. Antunes, A. Apostolidis, P. Berrebi, A. Duguid, A. Ferguson, J. L. Garcia-Marin, R. Guyomard, M. M. Hansen, K. Hindar, M. L. Koljonen, C. Largiader, P. Martinez, E. E. Nielsen, S. Palm, D. Ruzzante, N. Ryman & C. Triantaphyllidis, 1999. Conservation genetic management of brown trout (Salmo trutta L.) in Europe. Report by the concerted action on identification, management and exploitation of genetic resources in the brown trout (Salmo trutta) (“TROUTCONCERT”; EU FAIR CT97-3882). ISBN 87-987732-0-8 1999.Google Scholar
- Langella, O., 2002. POPULATIONS 1.2.26. Logiciel de Génétique de populations. Laboratoire populations, génétique et évolution. CNRS UPR 9034. Gif-sur-Yvette. France [available from http://www.bioinformatics.org/project/?group_id=84].
- Nei, M., 1987. Molecular evolutionary genetics. Columbia University Press, New York.Google Scholar
- Niksirat, H. & A. Abdoli, 2009. On the status of the critically endangered Caspian brown trout, Salmo trutta caspius, during recent decades in the southern Caspian Sea basin. Zoology in the Middle East 46: 55–60.Google Scholar
- Osinov, A. G. & L. Bernatchez, 1996. “Atlantic” and “Danube” phylogenetic groups of the sea trout Salmo trutta complex: genetic divergence, evolution, protection. Voprosy Ikhtiologii 36: 762–786.Google Scholar
- Presa, P. & R. Guyomard, 1996. Conservation of microsatellites in three species of salmonids. Journal of Fish Biology 49: 1326–1329.Google Scholar
- Rohlf, F., 1993. NTSYS-pc. Numerical taxonomy and multivariate analysis system, Version 2.1. Setauket, New York.Google Scholar
- Sambrook, J., E. F. Fritsch & T. Maniatis, 1989. Molecular cloning: a laboratory manual. Cold Spring Harbor, New York.Google Scholar
- Schneider, S., D. Roessli & L. Excoffier, 2000. Arlequin, Version 2.000: a software for population genetics data analysis. G.A.B. Laboratory). University of Geneva, Switzerland, Geneva.Google Scholar
- Sedgwick, S. D., 1995. Trout farming handbook. Alden Press, Oxford.Google Scholar