Publication Date:
2017-12-12
Description:
Periphyton with different biomass levels were grown in-situ in the Kiel Fjord and used for short-term laboratory experiments to study the grazing of the periwinkle Littorina littorea. Ingestion rates increased with biomass in a saturating function as described by Holling's type II functional response model, with a maximal ingestion rate of ca. 260 μg chlorophyll day−1 for 2 cm periwinkles. The half saturation constant of the ingestion rate was ca. 2 μg chlorophyll cm−2. At subsaturating food levels, L. littorea increased the area grazed per time but not intensity of grazing within that area. L. littorea is a moderately selective periphyton grazer. It fed on all algal species present, but the tube-dwelling diatoms Amphipleura rutilans and Haslea crucigera suffered significantly smaller grazing losses than the other species. However, the relative protection of those diatoms against periwinkle grazing decreased with higher biomass and with a higher load of easily ingestible epiphytes.
Type:
Article
,
PeerReviewed
Format:
text
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