Rocky shore trematodes of the west coast of Sweden: distribution and life cycle strategies
Direct access to intermediate and final hosts is critical for successful trematode life cycle completion. The harsh environmental conditions of the wave-exposed rocky shores of the Swedish west coast seriously hamper trematode transmission. Limited numbers of potential host species are another obstacle for survival. In this case, paraxenia, or the ability of parasites to simultaneously use multiple host species, is of utmost importance in promoting distribution in a wide range of microhabitats. Our purpose was to examine trematode spatial distribution and life cycle strategies under these severe conditions in order to assess specific life history patterns linked to their transmission. Estimation of overall parasitological load was carried out by extensive sampling of all available potential hosts in a wide range of microhabitats (rock pools, rock surfaces, cracks and crevices) from lower to upper littoral levels on the rocky shores of two islands in the Skagerrak Strait, Saltö and Ursholmen. Log-linear analysis was performed separately for sporocysts and metacercariae to evaluate parasite prevalence and intensity values for the second intermediate snail host Littorina saxatilis. A detailed study of the spread of Renicola spp. metacercariae using randomly amplified polymorphic DNA technique revealed two additional previously unreported second intermediate hosts (L. littorea and L. saxatilis) for R. thaidus. Several interesting combinations of transmission patterns were noted demonstrating species plasticity in terms of host use.
- Curtis L.A. 2002. Ecology of larval trematodes in three marine gastropods. Parasitology, 124, S43-S56.
- Davey J.T. 1983. The digenean parasites of Littorina neritoides (L.) in relation to microhabitat on the Plymouth breakwater. Canadian Journal of Zoology, 61, 1058-1061.
- Galaktionov K. V. 1993. Trematodes life cycles as the components of ecosystems. Kola Scientific Centre, Apatity (In Russian).
- Galaktionov K.V., Dobrovolskiy A.A. 2003. The biology and evolution of trematodes. An essay on the biology, morphology, life cycles, transmissions, and evolution of digenetic trematodes. Kluwer Academie Publisher, The Netherlands.
- Galaktionov K.V., Skirnisson K. 2000. Digeneans from intertidal molluscs of SW Iceland. Systematic Parasitology, 47, 87- 101.
- Granovitch A.I.1999. Parasitic systems and the structure of parasite populations. Helgoland Marine Research, 53, 9-18.
- Granovitch A.I., Johannesson K. 2000. Digenetic trematodes in four species of Littorina from the West coast of Sweden. Ophelia, 53,55-65.
- James B.L. 1968. The distribution and keys of species in the family Littorinidae and of their digenean parasites, in the region of Dale, Pembrokeshire. Field Studies, 2, 615-650.
- Lauckner G. 1980. Diseases of Mollusca: Gastropoda. In: Diseases of marine animals (Ed. O. Kinne). Book 1. Wiley, Chichester.
- Lauckner G. 1984. Impact of trematode parasitism on the fauna of a North Sea tidal flat. Helgoländer Meeresunters, 37,185-199.
- McCarthy H.O., Fitzpatrick S., Irwin S.W. 2002. Life history and life cycles: production and behaviour of trematode cercariae in relation to host exploitation and next-host characteristics. Journal of Parasitology, 88, 910-918.
- Mikhailova N.A., Johannesson K. 1998. A comparison of different protocols for RAPD analysis of Littorina. Hydrobiologia, 378, 33-42.
- Mouritsen K.N., Poulin R. 2002. Parasitism, community structure and biodiversity in intertidal ecosystems. Parasitology, 124, S101-S117.
- Parker G.A., Chubb J.C., Ball M.A., Roberts G.N. 2003. Evolution of complex life cycles in helminth parasites. Nature, 425, 480-484.
- Sannia A., James B.L. 1977. The Digenea in marine molluscs from Eyjafjordur, North Iceland. Ophelia, 16, 97-109.
- Shigin A.A. 1978. Towards to the role of free-living stages of trematodes in the communities. Parazitologiya, 12, 193-200 (In Russian).
- Stunkard H.W. 1964. Studies of trematode genus Renicola: observations on the life-history, specificity, and systematic position. Biological Bulletin of the Marine Laboratory, Woods Hole, 126, 468-489.
- Werding B. 1969. Morphologie, Entwicklung und Ökologie digener Trematoden-Larven der Strandschnecke Littorina littorea. Marine Biology, 3, 306-333.
- Williams J.K.G., Kubelik A.R., Livak K.J., Rafalsky J.A., Tingley S .V. 1990. DNA polymorphisms amplified by arbitrary primers are useful as genetic markers. Nucleic Acids Research, 18, 6531-6535.
- Zander C.D., Reimer L.W. 2002. Parasitism at the ecosystem level in the Baltic Sea. Parasitology, 124, S119-S135.