Morphological variations in Mytilus from the French coasts in relation to the occurrence and distribution of M. galloprovincialis Lamarck
Seed, R. (1972). Morphological variations in Mytilus from the French coasts in relation to the occurrence and distribution of M. galloprovincialis Lamarck. Cah. Biol. Mar. 13(3): 357-384, 4 plates In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more | |
Abstract | Both M. edulis and M. galloprovincialis on the coasts of France showed considerable variability, especially in shell shape, and on this character alone many individuals would undoubtedly have been mis-identified. However, the majority of galloprovincialis could generally be identified by their some-what more pointed and downturned umbones, frequently associated with some form of breaking or with a prominent umbo/lunule swelling. The dark colour of the mantle edge, absence of longitudinal rays on the shell and the small size of the anterior adductor muscle scar and hinge plates generally proved to be more reliable taxonomic characters than external shell morphology. M. galloprovincialis is the dominant mussel in the Mediterranean. It also extends along the length of the Atlantic coast of France and into the Channel as far as the Contentin. A few individual were recorded on the west coast of the Cotentin but none were found east of Cherbourg. M. edulis on the other hand, occurred at all the stations on the Channel and Atlantic coasts but very few positive identifications were made in the Mediterranean. Although both M. galloprovincialis and the 'Padstow mussel' from south-west England exhibit wide variations, particularly in their shell morphology, the striking similarity between animals from similar environmental conditions indicates quite conclusively that these mussels are synonymous forms of Mytilus. |
|