Morphological Variation in Fucus Vesiculosus Populations along Temperature and Salinity Gradients in Iceland.

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Kalvas, A., Kautsky, L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1998
• Subjects: Holdfast; Iceland
• Online Access: https://doi.org/10.1017/s0025315400044921; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315400044921

Geographical morphological variations in Fucus vesiculosus populations were studied along the coast of Iceland. Principal component analysis (PCA) based on 11 morphological characters clustered the 26 sampling sites into four different morphological types as follows: (1) a morphological type found along the S-SW-W coast; (2) an intermediate form comprising only two populations in the NW; (3) a type found along the N-NE-E-SE coast; and (4) a type found independent of geographical area, in estuaries and at sites influenced by large freshwater outflows. Populations influenced by low salinity had significantly ( P ≤ 0·001) shorter thalli, a shorter distance from the holdfast to the oldest dichotomy, smaller fronds, narrower stipes and midrib width compared to the morphology of all other more saline populations. No significant difference in frond width was found between the S-SW-W and the N-NE-E-SE populations. However, significant ( P ≤ 0·001) morphological differences between them were observed, the former having shorter thalli, a greater distance from the holdfast to the oldest dichotomy, narrower stipes and smaller midrib width compared to the latter.