UBC Theses and Dissertations
Protein variation of some pacific euphausiids in relation to environmental stability : An intraspecific and interspecific study Bromley, Gregory J.
The degree of biochemical variability is, in many cases, thought to be related to environmental stability. Intraspecific protein variation was examined in Euphausia pacifica using starch gel electrophoresis. Specimens were collected from eight oceanic and three neritic stations over a wide geographic area. The interspecific aspect of this study examined the general protein patterns of five species of North Pacific euphausiids. Temperature, salinity and oxygen were monitored, at the time of biological collections, in order to distinguish between water types. Two major protein patterns characterize E. pacifica from the different regions. The pattern possessing the greatest number of bands occurs in highest frequency in areas of greatest environmental instability (as characterized by temperature, salinity, and oxygen); the highest frequency occurrence of the pattern with the lowest number of bands is in environmentally stable regions. The expression of each pattern appears related to the degree of fluctuation of the physical parameters monitored, but these parameters are not suggested as the direct cause of which pattern is expressed. The physical parameters serve only as a tool for characterizing the stability of a region. Analysis of the electrophoretic protein patterns from five species of euphausiids, Euphausia pacifica, E. gibboides, Thysanoessa spinifera, T. inspinata and Nematoscelis difficilis, revealed that each species possesses a unique protein pattern. The interspecific and intergeneric similarities of protein patterns parallel the existing morphological taxonomy.
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