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| Dennert, H.G.; Dennert, A.L.; Kant, P.; Pinkster, S.; Stock, J.H.. |
| 1. The real identity has been studied of juvenile gammarids, that were found in the fresh-water tidal region of the River Slack (France), 3 to 4 km inland of the mouth of its estuary. At the outset, these juveniles were (on basis of their morphology) considered to belong to Gammarus salinus. 2. Rearing demonstrated that the juveniles in question developed into adult Gammarus zaddachi. This indicates that the morphological criteria used in discriminating between G. salinus and G. zaddachi fail in juvenile material. Several morphological criteria are discussed and tested. It appears that a 100% certain key character does not exist, meaning that it is not possible to identify with absolute certainty all individuals in mixed populations of the two species. 3.... |
| Tipo: Article / Letter to the editor |
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| Ano: 1969 |
URL: http://www.repository.naturalis.nl/record/504231 |
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| Pinkster, S.; Dennert, A.L.; Stock, B.; Stock, J.H.. |
| In addition to the well-known freshwater occurrence of Gammarus duebeni in the inland of Ireland, a similar inland occurrence in the western part of Brittany (= Bretagne, France) is demonstrated. In Brittany, as in Ireland, G. duebeni occurs in waters with low sodium concentrations (often less than 23 mg/l), whereas elsewhere in its range, G. duebeni lives in waters with a raised sodium content (either in mixohaline waters, or in “fresh” waters loaded with salts through gales from sea). Reid has proposed the designation G. duebeni α for the Irish freshwater form, G. duebeni ß for the brackish water form. The subdivision of G. duebeni is strongly reinforced by the findings of Sutcliffe et al., indicating physiological differences between the α and ß form.... |
| Tipo: Article / Letter to the editor |
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| Ano: 1970 |
URL: http://www.repository.naturalis.nl/record/504522 |
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