Change search
ReferencesLink to record
Permanent link

Direct link
Resurrected past-century Ceriodaphnia quadrangula highlight  differences between pheno- and genotypic expressions
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. (Tvärminne Zoological Station, Hanko, Finland)
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The hatching of cladoceran ephippia from a 15 cm long sediment core was investigated, and Ceriodaphnia quadrangula -clones were isolated from different sediment layers. Bosmina-microfossil data were also analyzed, and compared with the corresponding data from a Pb210-dated core, which allowed us to infer the age of the sediment-layers. Using changes in Bosmina-microfossil morphologies, we were furthermore able to infer the presence of different regimes of fish-predation. C. quadrangula was found to hatch in layers with an inferred age of approximately a century. Newly hatched individuals had smaller eye-size in sediment layers corresponding to high predation by young-of-the-year perch. Newly hatched individuals also generally had a marked neck-spine. In contrast, morphological characters of C. quadrangula -clones reared in the laboratory over several generations showed no variation in relation to predation regime, indicating the absence of fixed genotype-level changes. Furthermore, the laboratory-grown clones only rarely produced a neck-spine. The results suggest phenotypic variation in response to the regime under which ephippia were produced.

National Category
Natural Sciences
Research subject
URN: urn:nbn:se:umu:diva-53560OAI: diva2:513453
Available from: 2012-04-02 Created: 2012-04-02 Last updated: 2012-04-02Bibliographically approved
In thesis
1. Fingerprints of planktivory: paleolimnological evidence of past fish community structure and dynamics
Open this publication in new window or tab >>Fingerprints of planktivory: paleolimnological evidence of past fish community structure and dynamics
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Planktivorous fish affect the species composition, size and morphology of their zooplankton prey by size selective predation. Remains of cladocerans are deposited in the lake sediments and this microfossil community hence reflects the historical changes in the planktivore fish community. Most earlier work on quantitatively inferring past planktivory deals with ephippia (resting eggs) of Daphnia, however these remains are very scarce in northern Swedish lakes. In these lakes, often dominated by fish that are not obligate planktivores, such as perch (Perca fluviatilis), the individual size to a large degree determines the type of resource consumed. Therefore, in these lakes, the size distribution as well as the density of the fish community determines the overall planktivoryThis thesis deals with evaluating the use of Bosmina remains in the sediment as indicators of past planktivory. I developed a transfer function based on Bosmina remains to be used in oligotrophic lakes with omnivorous species to reconstruct past planktivory. I test the transfer function in a lake where the history is to a large extent known. Furthermore, in this thesis a novel quantitative measure of planktivore pressure, the PCC (Planktivore Community Capacity) was developed. It was also possible to compare the morphology measurements of carapace length and mucro length of contemporary Bosmina sampled in the lake, with the same measurements on microfossils of Bosmina sedimented during the corresponding time period. By using the resurrection approach this thesis also evaluates the use of Ceriodaphnia clones as indicators of micro-evolutionary responses to past planktivory.From the studies in this thesis I can draw some major conclusions; the morphological measurements carapace length and mucro length of Bosmina can be used to infer past planktivory in northern Swedish lakes. PCC has a higher explanatory power than CPUE in these lakes dominated by omnivorous fish. The morphology of the contemporary Bosmina corresponds well with the remains found in the sediment dating from the same time period. Both the contemporary and microfossil Bosmina changes in body size characteristics was in turn strongly related to PPC. Finally, the hatching of Ceriodaphnia ephippia is promising for studying past planktivory, both because of the high viability of the ephippia and the relationship between eye area and inferred PCC.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2012. 33 p.
planktivory, foraging efficiency, cladoceran remains, Bosmina, planktivore community capacity, PCC, Ceriodaphnia, reserrection
National Category
Research subject
Animal Ecology
urn:nbn:se:umu:diva-53561 (URN)978-91-7459-395-2 (ISBN)
Public defence
2012-04-27, KBC-huset, Lilla Hörsalen, KB3A9, Umeå Universitet, Umeå, 13:00 (English)
Available from: 2012-04-04 Created: 2012-04-02 Last updated: 2012-04-02Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Reinikainen, MarkoÅhlén, Emma
By organisation
Department of Ecology and Environmental Sciences
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 37 hits
ReferencesLink to record
Permanent link

Direct link