Algal Preferences in the Masking Behaviour of the Spider Crab, Notomithrax ursus

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Author
Ertel, Catherine Monica
Date
2008Permanent Link
http://hdl.handle.net/10092/2258Thesis Discipline
EcologyDegree Grantor
University of CanterburyDegree Level
MastersDegree Name
Master of ScienceThe purpose of this study was to examine the masking preferences of the spider crab, Notomithrax ursus. The algal composition of the mask in the natural habitat at Kaikoura was examined to determine the general rules the crab follows when decorating itself. The effects of size and sex on the mask composition were examined, as well as determining how the composition of the mask varies by body part. The preference of the crabs was further examined through the use of choice and background change experiments in the laboratory. It was determined that the preference of certain types of algae for mask material is not entirely dependent on their relative abundance in the environment. Possible explanations for this behaviour are given.