Abstract
Littorina tenebrosa is a small fragile-shelled periwinkle which lives on permanently submerged algae in coastal lagoons and non-tidal brackish pools. This periwinkle is a member of the rough periwinkle group which also comprises Littorina saxatilis, L. arcana, L. compressa and L. neglecta and is most closely related to L. saxatilis although its exact systematic status is in some doubt. Based on its unique ecology many believe L. tenebrosa to be a valid species. However, shell morphometric and allozyme analyses on Scottish and Swedish populations of L. tenebrosa and L. saxatilis have indicated that the two periwinkles are virtually identical. Preliminary results on five allozyme loci (AAT-1, GPI, PGM-1, PGM-2 and PNP) in samples of L. tenebrosa and L. saxatilis from Golam Head, Lettermullen, and other locations on the west coast of Ireland show L. tenebrosa to be genetically differentiated from L. saxatilis At Golam Head, where opportunities for gene flow occur between the two taxa, L. tenebrosa is as genetically differentiated from local L. saxatilis as it is from L. saxatilis from more geographically distant locations.
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Gosling, E.M., Wilson, I.F. & Andrews, J. A preliminary study on genetic differentiation in Littorina saxatilis from Galway Bay, Ireland: Littorina tenebrosa Montagu – a valid species or ecotype?. Hydrobiologia 378, 21–25 (1998). https://doi.org/10.1023/A:1003217016876
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DOI: https://doi.org/10.1023/A:1003217016876