Heart rates and amplitudes were measured for both intact
animals (in situ) and isolated hearts (in vitro) of the Dungeness crab,
Cancer magister, exposed to low levels in oxygen. Recordings were
also made of gill ventilation rate by measuring the frequency of
scaphognathite (gill bailer) beats.
Both the in vitro...
Great importance has been attributed to the visual aspects of
sexual communication in semi-terrestrial crabs and although P.
crassipes may utilize visual signals, pheromones and chemotactile
signals are important in the release of mating behavior. In the subtidal
C. magister pheromones seem to mediate both courtship and
mating behavior. Visual...
Osmotic and ionic regulation was studied in the Dungeness
crab, Cancer magister, after acute exposure to a range of five
salinities from 25% to 125% sea water (100% = 32%). Blood, urine
and muscle tissue were sampled at 24 and 48 hours after exposure.
Analyses were made of blood and...
Organismal tolerance to abiotic environmental stresses contributes significantly to setting the distribution limits of organisms, as demonstrated by vertical zonation patterns in the marine intertidal zone. In this thesis, the ultimate (evolutionary) and proximate (mechanistic) causes of tolerance to temperature and emersion stresses associated with the intertidal zone were examined...
The Hemigrapsus oregonensis population at Coquille Point in
the Yaquina Bay Estuary on the Central Oregon Coast was studied
from April, 1972 through May, 1973. The population was found to be
vertically stratified from the 1 ft level to the 5 ft level. Population
densities were found to be most...