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Host-based identification is not supported by morphometrics in natural populations of Gyrodactylus salaris and G. thymalli (Platyhelminthes, Monogenea)

Published online by Cambridge University Press:  16 August 2007

K. OLSTAD ,
A. P. SHINN ,
L. BACHMANN  and
T. A. BAKKE
K. OLSTAD*
Affiliation:
Natural History Museum, Department of Zoology, University of Oslo, P.O. Box 1172, NO-0318 Oslo, Norway
A. P. SHINN
Affiliation:
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK
L. BACHMANN
Affiliation:
Natural History Museum, Department of Zoology, University of Oslo, P.O. Box 1172, NO-0318 Oslo, Norway
T. A. BAKKE
Affiliation:
Natural History Museum, Department of Zoology, University of Oslo, P.O. Box 1172, NO-0318 Oslo, Norway
*
*Corresponding author: Natural History Museum, Department of Zoology, University of Oslo, P.O. Box 1172, NO-0318 Oslo, Norway. Tel: +47 22 85 18 23. Fax: +47 22 85 18 37. E-mail: [email protected]
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Summary

Gyrodactylus salaris is a serious pest of wild pre-smolt Atlantic salmon (Salmo salar) in Norway. The closely related G. thymalli, originally described from grayling (Thymallus thymallus), is assumed harmless to both grayling and salmon. The 2 species are difficult to distinguish using traditional, morphometric methods or molecular approaches. The aim of this study was to explore whether there is a consistent pattern of morphometrical variation between G. salaris and G. thymalli and to analyse the morphometric variation in the context of ‘diagnostic realism’ (in natural populations). Specimens from the type-material for the 2 species are also included. In total, 27 point-to-point measurements from the opisthaptoral hard parts were used and analysed by digital image processing and uni- and multivariate morphometry. All populations most closely resembled its respective type material, as expected from host species, with the exception of G. thymalli from the Norwegian river Trysilelva. We, therefore, did not find clear support in the morphometrical variation among G. salaris and G. thymalli for an a priori species delineation based on host. The present study also indicates an urgent need for more detailed knowledge on the influence of environmental factors on the phenotype of gyrodactylid populations.

Keywords

morphologysystematicsAtlantic salmonSalmo salargraylingThymallus thymallus
Type
Research Article
Information
Parasitology , Volume 134 , Issue 14 , December 2007 , pp. 2041 - 2052
Copyright
Copyright © Cambridge University Press 2007

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References

REFERENCES

Bakke, T. A., Harris, P. D. and Cable, J. (2002). Host specificity dynamics: observations on gyrodactylid monogeneans. International Journal for Parasitology 32, 281–308. DOI:10.1016/S0020-7519(01)00331-9CrossRefGoogle ScholarPubMed
Bakke, T. A., Cable, J. and Harris, P. D. (2007). The biology of gyrodactylid monogeneans: the “Russian Doll-killers”. Advances in Parasitology 64, 161–376. DOI: 10.1016/S0065-308(06)64003-7CrossRefGoogle Scholar
Cable, J., Harris, P. D. and Bakke, T. A. (2000). Population growth of Gyrodactylus salaris (Monogenea) on Norwegian and Baltic Atlantic salmon (Salmo salar) stocks. Parasitology 121, 621–629. DOI: 10.1017/S0031182000006971CrossRefGoogle ScholarPubMed
Cunningham, C. O. (1997). Species variation within the internal transcribed spacer (ITS) region of Gyrodactylus (Monogenea: Gyrodactylidae) ribosomal RNA genes. Journal of Parasitology 83, 215–219.CrossRefGoogle Scholar
Dávidová, M., Jarkovský, J., Matĕjusová, I. and Gelnar, M. (2005). Seasonal occourence and metric variability of Gyrodactylus rhodei Žitňan, 1964 (Monogenea, Gyrodactylidae). Parasitology Research 95, 398–405. DOI: 10.1007/S00436-005-1311-0CrossRefGoogle Scholar
Dmitrieva, E. and Dimitrov, G. (2002). Variabiltiy in the taxonomic characters of Black Sea gyrodactylids (Monogenea). Systematic Parasitology 51, 199–206.CrossRefGoogle Scholar
Ergens, R. (1983). Gyrodactylus from Eurasian freshwater Salmonidae and Thymallidae. Folia Parasitologica 30, 15–26.Google Scholar
Hammer, Ø., Harper, D. A. T. and Ryan, P. D. (2001). PAST: Paleontological Statistics Software Package for Education and Data Analysis. Palaeontologia Electronica 4, 9pp.Google Scholar
Hansen, H., Bachmann, L. and Bakke, T. A. (2003). Mitochondrial DNA variation of Gyrodactylus spp. (Monogenea, Gyrodactylidae) populations infecting Atlantic salmon, grayling, and rainbow trout in Norway and Sweden. International Journal for Parasitology 33, 1471–1478. DOI: 10.1016/S0020-7519(03)00200-5.CrossRefGoogle ScholarPubMed
Hansen, H., Martinsen, L., Bakke, T. A. and Bachmann, L. (2006). The incongruence of nuclear and mitochondrial DNA variation supports conspecificity of the monogenean parasites Gyrodactylus salaris and G. thymalli. Parasitology 133, 639–650. DOI: 10.1017/S0031182006000655CrossRefGoogle ScholarPubMed
Harris, P. D., Cable, J., Tinsley, R. C. and Lazarus, C. M. (1999). Combined ribosomal DNA and morphological analysis of individual gyrodactylid monogeneans. Journal of Parasitology 85, 188–191.CrossRefGoogle ScholarPubMed
Harris, P. D., Shinn, A. P., Cable, J. and Bakke, T. A. (2004). Nominal species of the genus Gyrodactylus von Normann 1832 (Monogenea: Gyrodactylidae), with a list of principal host species. Systematic Parasitology 59, 1–27. DOI: 10.1023/B:SYPA.0000038447.52015.e4CrossRefGoogle Scholar
Huyse, T. and Volckaert, F. A. M. (2002). Identification of a host-associated species complex using molecular and morphometric analyses, with the description of Gyrodactylus rugiensoides n. sp. (Gyrodactylidae, Monogenea). International Journal for Parasitology 32, 907–919. DOI: 10.1016/S0020-7519(02)00026-7CrossRefGoogle Scholar
Johnsen, B. O., Møkkelgjerd, P. I. and Jensen, A. J. (1999). The parasite Gyrodactylus salaris on salmon parr in Norwegian rivers, status report at the beginning of year 2000. NINA Oppdragsmelding 617, 1–129. (In Norwegian.)Google Scholar
Jolicoeur, P. and Mosimann, J. (1960). Size and shape in the painted turtle. A principal component analysis. Growth 24, 339–354.Google Scholar
Jørgensen, T. R., Larsen, T. B., Jørgensen, L. G., Bresciani, J., Kania, P. W. and Buchmann, K. (2007). Characterisation of a low pathogenic form of Gyrodactylus salaris from rainbow trout. Diseases of Aquatic Organisms 73, 235–244.CrossRefGoogle ScholarPubMed
Kulemina, I. V. (1977). Size variability of the adhesive elements in some species of Gyrodactylus. In Investigations of Monogeneans in the USSR (ed. Skarlato, O. A.), pp. 38–41. Oxonian Press Pvt. Ltd 1987, New Dehli, India.Google Scholar
Malmberg, G. (1957). Om förekomsten av Gyrodactylus på svenska fiskar. Skrifter utgivna av Södra Sveriges Fiskeriförening, Årsskrift 1956, 19–76. (In Swedish.)Google Scholar
Malmberg, G. (1970). The excretory systems and the marginal hooks as a basis for the systematics of Gyrodactylus (Trematoda, Monogenea). Arkiv für Zoologie 23, 1–235.Google Scholar
McHugh, E. S., Shinn, A. P. and Kay, J. W. (2000). Discrimination of the notifiable pathogen Gyrodactylus salaris from G. thymalli (Monogenea) using statistical classifiers applied to morphometric data. Parasitology 121, 315–323. DOI: 10.1017/S0031182099006381CrossRefGoogle Scholar
Meinilä, M., Kuusela, J., Ziętara, M. S. and Lumme, J. (2004). Initial steps of speciation by geographic isolation and host switch in salmonid pathogen Gyrodactylus salaris (Monogenea: Gyrodactylidae). International Journal for Parasitology 34, 515–526. DOI: 10.1016/j.ijpara.2003.12.002CrossRefGoogle ScholarPubMed
Mo, T. A. (1991 a). Seasonal variations of opisthaptoral hard parts of Gyrodactylus salaris Malmberg, 1957 (Monogenea: Gyrodactylidae) on parr of Atlantic salmon Salmo salar L. in the river Batnfjordselva, Norway. Systematic Parasitology 19, 231–240.CrossRefGoogle Scholar
Mo, T. A. (1991 b). Variations of opisthaptoral hard parts of Gyrodactylus salaris Malmberg, 1957 (Monogenea: Gyrodactylidae) on rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) in a fish farm, with comments on the spreading of the parasite in south-eastern Norway. Systematic Parasitology 20, 1–9.CrossRefGoogle Scholar
Mo, T. A. (1991 c). Variations of opisthaptoral hard parts of Gyrodactylus salaris Malmberg, 1957 (Monogenea: Gyrodactylidae) on parr of Atlantic salmon Salmo salar L. in laboratory experiments. Systematic Parasitology 20, 11–19.CrossRefGoogle Scholar
Mo, T. A., Norheim, K. and Hellesnes, I. (2004). The surveillance and control programme for Gyrodactylus salaris in Atlantic salmon and rainbow trout in Norway. Norsk Veterinærtidsskrift 3, 157–163. (In Norwegian, English summary.)Google Scholar
Olstad, K., Robertsen, G., Bachmann, L. and Bakke, T. A. (2007). Variation in host preference within Gyrodactylus salaris (Monogenea): an experimental approach. Parasitology 134, 589–597. DOI: 10.1017/S0031182006001715CrossRefGoogle ScholarPubMed
Reyment, R. A., Blackith, R. E. and Campell, N. A. (1984). Multivariate Morphometrics, 2nd Edn. Academic Press, London.Google Scholar
Robertsen, G., Hansen, H., Bachmann, L. and Bakke, T. A. (2007). Arctic charr (Salvelinus alpinus) is a suitable host for Gyrodactylus salaris (Monogenea, Gyrodactylidae) in Norway. Parasitology 134, 257–267. DOI: 10.1017/S0031182006001223CrossRefGoogle ScholarPubMed
Shinn, A. P., Hansen, H., Olstad, K., Bachmann, L. and Bakke, T. A. (2004). The use of morphometric characters to discriminate specimens of laboratory-reared and wild populations of Gyrodactylus salaris and G. thymalli (Monogenea). Folia Parasitologica 51, 239–252.CrossRefGoogle Scholar
Soleng, A. and Bakke, T. A. (2001). The susceptibility of grayling, Thymallus thymallus to experimental infections with the monogenean Gyrodactylus salaris. International Journal for Parasitology 31, 793–797. DOI: 10.1016/S0020-7519(01)00188-6CrossRefGoogle ScholarPubMed
Sterud, E., Mo, T. A., Collins, C. M. and Cunningham, C. O. (2002). The use of host specificity, pathogenicity, and molecular markers to differentiate between Gyrodactylus salaris Malmberg, 1957 and G. thymalli Žitňan, 1960 (Monogenea: Gyrodactylidae). Parasitology 124, 203–213. DOI: 10.1017/S0031182001001044CrossRefGoogle Scholar
Ziętara, M. S. and Lumme, J. (2002). Speciation by host switch and adaptive radiation in a fish parasite genus Gyrodactylus (Monogenea: Gyrodactylidae). Evolution 56, 2445–2458.Google Scholar
Žitňan, R. (1960). Gyrodactylus thymalli sp. nov. from the fins of the grayling (Thymallus thymallus). Helminthologia 2, 266–269. (In German.)Google Scholar