This thesis deals with the importance of salinity to the distribution of three chironomid species of the genus Chironomus (C. anthracinus. C. athalassicus. and C. tentans). Research to date suggests that salinity and coexistence problems are the major factors influencing the distribution of the chironomid fauna of fresh and saline lakes in the Cariboo and Chilcotin areas of central British Columbia.
The difference in the distribution of these three Chironomus species is particularly interesting. The investigation of the importance of salinity to their distribution consisted of a study of (i) the salinity tolerance of each species, (ii)the regulation of the haemolymph, and (iii) the influx and efflux of sodium and chloride ions.
Several conclusions were drawn from the investigation.
A difference in the salinity tolerance of each species was
found in the laboratory: C. anthracinus and C. tentans did
not survive at lake water conductivities above 9000 micro-o
mhos/cm at 25 C, C. athalassicus survived in lake water
conductivities at least as high as 15ยป000 micromhos/cm at o
25 C. Temperature affected the survival of each species in a similar way; at high temperatures survival time decreased. Sodium, potassium, and chloride as well as the concentration of the haemolymph were regulated by the three species at low salinities. C. athalassicus was the only species able to conform at higher external concentrations. C. athalassicus had a low sodium affinity and a powerful sodium uptake system compared to the other species. Chloride affinity and the power of the uptake system exceeded that of C. anthracinus and C. tentans.
The general conclusion reached was that salinity does affect the distribution of the three Chlronomus species. More research is called for in this and related areas in order to more fully understand the distribution of the chironomid fauna. / Science, Faculty of / Zoology, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/21039 |
| Date | January 1978 |
| Creators | Sargent, Randall Wayne |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| 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. |
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