Effects of artificial vegetation density on prey size selection by perch (Perca fluviatilis L.) feeding on the isopod Asellus aquaticus L.
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Predation from fish is a selective factor affecting species as well as size composition of invertebrate communities. In this study perch (Perca fluviatilis L.) was hypothesized to be size selective when choosing prey, and that selectivity would decrease with increasing visual obstacles, such as submerged vegetation. The prey size selectivity of perch and its relation to vegetation density were tested in the laboratory using artificial vegetation and the isopod Asellus aquaticus L. as prey. The results show that perch was size selective, preferring to feed on larger A. aquaticus. The results also show that the size selectivity decreased with increasing vegetation density. According to the results it would be expected to find increasing survival rates for Asellus aquaticus in vegetated areas compared to unvegetated areas. The selective predation for large invertebrates can be a mechanism creating local divergence within species, and structure invertebrate communities by making large sized invertebrates more common in densely vegetated areas.
Place, publisher, year, edition, pages
2010. , 8 p.
Asellus aquaticus, size-selective predation, optimal foraging theory, Perca fluviatilis, vegetation density
IdentifiersURN: urn:nbn:se:liu:diva-57218ISRN: LITH-IFM-G-EX--10/2334--SEOAI: oai:DiVA.org:liu-57218DiVA: diva2:323933
2010-05-31, Linköpings universitet, 13:40 (English)
UppsokLife Earth Science