Bodyshape ecology of threespine stickleback from Haida
Mark Spoljaric, MSc (2006)
- Body shape in many aquatic organisms
represents a compromise between hydrodynamic constraints and life history
requirements and typically body shape is highly conserved within a
species. I examine lateral body shape using digital imagery and geometric
morphometrics to quantify shape variables in three-spine stickleback from
Haida Gwaii. Even within this conserved body shape there are regular
differences in geometric morphology ( figure1 ).
- My main focus is the functional implication of body shape
variation between and within populations. So far we have been able to
relate differences in geometric morphology to habitat characteristics ( figure 2 ), tracking divergence
in form through the ancestral marine environment to highly derived lakes.
I am also currently studying the function of allometric changes and the
evolution of sexual dimorphism in body shape.
- Haida Gwaii are ideal for studying the evolution of form on an
isolated archipelago, as we know the current landscape is approximately
10,000 years old and the low lying lakes were initially colonized by
marine stickleback. In essence this experiment has been ongoing
since the retreat of the glaciers and offers an excellent opportunity to
study the evolutionary process. (Spoljaric and Reimchen, J. Fish Biol., in