- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- An experimental test of Dodson’s hypothesis that Ambystoma...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
An experimental test of Dodson’s hypothesis that Ambystoma and Chaoborust have complementary feeding niches Giguère, Louis
Abstract
The removal from an alpine pond of the eggs of a salamander, Ambystoma gracile, had a large impact on the zooplankton community. The pond was dominated by large Daphnia while nearby ponds, from which salamander eggs were not removed, were dominated by the small cladoceran Diaphancscma . The size at maturity of Diaptomus copepods increased by 0.3 to 0.4 mm compared to the previous year. Crop content analyses revealed that food intake of Ilnd and Illrd instar Chaoborus was low. IVth instars were scarce and their dry weight was 50% lower than in the previous year. When Ambystoma is abundant, it preys heavily upon Holopedium gibberum and Daphnia rosea which are not available as food to Chaoborus trivittatus. The reduction in the density of large zooplankters permits a competitor, Diaphancscma brachyurum , to flourish. It is the main food source, when available, of Ilnd and Illrd instar Chaoborus . In this indirect way, Chaoborus depends on vertebrate predation to successfully reach its IVth instar. This lends support to Dodson's hypothesis of complementary feeding niches.
Item Metadata
Title |
An experimental test of Dodson’s hypothesis that Ambystoma and Chaoborust have complementary feeding niches
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
1974
|
Description |
The removal from an alpine pond of the eggs of a salamander, Ambystoma gracile, had a large impact on the zooplankton community. The pond was dominated by large Daphnia while nearby ponds, from which salamander eggs were not removed, were dominated by the small cladoceran Diaphancscma . The size at maturity of Diaptomus copepods increased by 0.3 to 0.4 mm compared to the previous year. Crop content analyses revealed that food intake of Ilnd and Illrd instar Chaoborus was low. IVth instars were scarce and their dry weight was 50% lower than in the previous year. When Ambystoma is abundant, it preys heavily upon Holopedium gibberum and Daphnia rosea which are not available as food to Chaoborus trivittatus. The reduction in the density of large zooplankters permits a competitor, Diaphancscma brachyurum , to flourish. It is the main food source, when available, of Ilnd and Illrd instar Chaoborus . In this indirect way, Chaoborus depends on vertebrate predation to successfully reach its IVth instar. This lends support to Dodson's hypothesis of complementary feeding niches.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2010-02-01
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
DOI |
10.14288/1.0093483
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Campus | |
Scholarly Level |
Graduate
|
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.