Verbreitung der Halacardidae (Acari) im gezeitenbereich der Bretagne-küste, eine ökologische analyse 2. Quantitative Untersuchungen und Faunenanalyse = Distribution of Halacaridae (Acari) on the coast of Brittany. 2. Quantitative investigations on faunistic analysis
Bartsch, I. (1979). Verbreitung der Halacardidae (Acari) im gezeitenbereich der Bretagne-küste, eine ökologische analyse 2. Quantitative Untersuchungen und Faunenanalyse = Distribution of Halacaridae (Acari) on the coast of Brittany. 2. Quantitative investigations on faunistic analysis. Cah. Biol. Mar. 20(1): 363-383
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, meer
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| Abstract |
In most habitats investigated, the halacarid fauna is numerically dominated by the Rhombognathinae. On algae in the littoral fringe and in the upper eulittoral zone, the halacarids are often the dominant marine meiofauna group. In the littoral fringe, the Isobactrus species are predominant. In the upper eulittoral zone the most important genera are Rhombognathus, Isobactrus, Rhombognathides, and Metarhombognathus. Downshore the meiofauna is richer, the number of halacarid species increases, but the part of halacarids in the total meiofauna decreases. Mite colonization and species composition correlate with tidal level, density of algal growth, shape of algae and amount of epiphytes. The algal species play no or only a minor role. At low tide halacarid fauna plays a greater role on leaf-like fronds than on small, clustered, densely branched seaweeds or on algae covered by tufts of epiphytes. In sediments the halacarids never formed a similar high percentage in numbers as in the phytal layer. In well sorted medium-grained sand, the halacarids comprised <10% of the total meiofauna. In sediments influenced by brackish water, the percentage of mites was higher than in coastal areas. In unsorted rather coarse sand, the halacarids had >15% of the total meiofauna. In fine sediments, rich in organic material, mite numbers were insignificant. In salt marshes halacarids formed up to 10% of the meiofauna. The halacarid species found and their special habitats are mentioned. |
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