Developmental changes in the enzymes acetylcholinesterase
(EC 3.1.1.7) and pseudocholinesterase (EC 3.1.1.8) were
examined in ovo and in vitro in the neural retina of the
developing chick. In addition, investigations of cellular
interactions and hormones as possible control mechanisms of
enzyme synthesis were made.
The specific activity of acetylcholinesterase, a...
The distribution and abundance of the interstitial acoel turbellarian,
Diatomovora amoena Kozloff, 1965 was studied in an
estuarine intertidal sand flat in Yaquina Bay, Oregon, from May
1970 through May 1971.
Monthly measurements of biological (organics, sulfides, chlorophyll,
and carotenoids), pore water (salinity, pH,oxygen, and temperature),
and sediment (fine sediment...
A study was done on the zoogeography of species of oceanic
shrimp in the North Pacific from 22°N to 56°N and from 124°W to
145°E, using samples of shrimp collected from 1954 to 1969. These
collections were made during the following cruises: John R. Manning
Cruise 22, and the Hugh...
The heart rate, oxygen consumption, survivorship, and 1-lactate
accumulation were determined in the intertidal limpets Collisella pelta
and Collisella digitalis in relation to laboratory desiccation at 15°C
or 30°C. Water loss was computed as a percentage of total initial body
water (wet weight - dry weight). Although water was lost...
Description of anuran larvae with the use of staging tables is
a common practice in the study of frog life-histories, but there has
been no previous description or table of Ascaphus larvae. In comparing
Ascaphus larvae to a simplified staging table for anurans it
was found that these larvae vary...
Like other species interactions in ecological systems, host-pathogen interactions are influenced by environmental factors, landscape characteristics and the broader community context. My thesis explores the potential influences of food-web interactions (Chapter 2), climate change (Chapter 3), landscape structure and host movement patterns (Chapter 4), and the combined influences of local...
Phenetic relationships in insular populations of Lacerta sicula
and L. melisellensis correspond to geologic ages of the islands in two
regions of the Adriatic Sea. Populations of L. melisellensis on older
islands are more similar to populations of L. sicula than are L. melisellensis
from younger islands, and examination of...
Characteristics of bacterial clearance were investigated in the
purple sea urchin, Strongylocentrotus purpuratus (Echinodermata:
Echinoidea). Primary clearance kinetics were determined for three
bacteria, a marine Gram negative motile rod, a marine Gram positive non-motile
rod, and a fresh water fish pathogen, Aeromonas salmonicida.
Various doses of live bacteria were injected...
The object of this study was to investigate the possibilities
of tracing aggregational behavior among Bufo boreas boreas
larvae with reference to tadpole development, and to attempt to determine
what aggregational factors initiate and maintain this behavior.
Additionally, an attempt was made to determine the significance
of temperature as an...
In the field of herpetology, most studies of homing have been
carried out with anurans and, to a lesser degree, reptiles. Studies
of orientation and navigation in urodeles have been limited to a few
brief notes and the extensive investigation of Taricha rivularis by
Twitty (1959 and 1964).
The rough-skinned...
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...
Diet variation among individuals within populations is widespread. Often diet differences among individuals are attributable to obvious differences among individuals such as age, sex, or morphology. However, growing evidence suggests that individual diet variation is also common among seemingly identical individuals within populations. This phenomenon has been termed individual diet...
The term "interaction" in evolutionary biology and ecology
describes the relationships among variables in two classes of causal
models. In the first, "interaction" refers to the influence of a
single putatively causal variable on a variable of interest. In the
second class of models, the term applies when a third...