A Behavioral and Ecological Study of the Fiddler Crab UCA CRENULATA

<p>The social interaction and behavioral activities of a population of fiddler crabs, Uca crenulatat located in the "Aqua Hedianda" lagoon in Carlsbad, California, is the subject of this study.</p> <p>Variations in environmental factors as well as seasonal behavioral changes cause an important fluctuation in the male to female ratio and in population density.</p> <p>A daily and seasonal variation is observed in the different behavioral activities displayed by the crab colony and are caused by biotic and abiotic environmental factors and by intrinsic hormonal changes.</p> <p>A male color variation from dark to light is related to behavioral changes during the breeding season. This lightening of the carapace, most likely caused by sexual hormones, is a thermoregulatory advantage for the mating male.</p> <p>Studies of the waving behavior of the light colored male in presence of a female, shows wave periods ranging from 1 to 5 seconds. The rate of the wave's major component corresponds to the optimum stimulus speeds (30-50 degrees,/ sec.) of a rate sensitive neuron found in the optic nerve of the crabs. These results show a strong relation between behavioral data obtained on the field and physiological data concerning movement and rate selective neurons in the eye of the crab U. crenulata.</p> <p>The identification of 9 different stages in the egg development of U. crenulata as well as the time necessary to complete the incubation shows that the breeding cycle length is 2 weeks.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physiology

Year

1985

Author dc:creator

• Hantson-Parker, Magali

Contributors dc:contributor

• Donald Rafuse
• John Leonora
• Earl Lathrop
• T. Joe Willey
• Leonard Brand

• Physiology
• Fiddler-crabs -- Behavior; Fiddler-crabs -- Ecology

Statement dc:rights

• This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Language dc:language

English

Repository record dc:identifier

https://scholarsrepository.llu.edu/etd/567

OAI identifier oai:identifier

oai:scholarsrepository.llu.edu:etd-1740