Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Zen Faulkes

Second Advisor

Dr. Matthew Terry

Third Advisor

Dr. Christopher Vitek


Marmorkrebs is a parthenogenetic crayfish with no indigenous populations. They have been introduced in several countries and could become an invasive species. Individuals introduced in Germany had longer, sharper spines, suggesting an adaptation to predators via developmental plasticity. This was tested by exposing juveniles to the odor of a fish during development and comparing them to controls. Subsequent spine length or sharpness did not differ. Other crayfish detect predators via an alarm cue, hemolymph, and exhibit avoidant behavior in response. I hypothesized that Marmorkrebs would also treat hemolymph as an alarm cue. The behavior of adult crayfish exposed to food, fish odor, or hemolymph were recorded. Results showed no difference across conditions, indicating that Marmorkrebs do not use hemolymph or fish odor as cues.


Copyright 2012 Loren Samantha Beard. All Rights Reserved.

Granting Institution

University of Texas-Pan American