Chemoreception is one of the dominant sensory modalities for many species of salamanders (reviewed in Chapter 2). At least seven of the ten currently recognized salamander families are known to respond to some sort of chemical cue. These responses are as varied as delaying hatching, seeking refuge, or initiating aggressive...
In nature, animals survive threats by responding physiologically and behaviorally in ways that are appropriate to the situation. Which responses are appropriate depend on the animals' surroundings and current physiological and behavioral state. This dissertation investigated the neuroendocrine mechanisms that control context-dependent behavioral responses to stress by focusing on the...
The host fish for this study were collected from January
through June of 1965. Tidepools were selected at Bar View, Cape
Arago, Neptune State Park, Seal Rock, and Yaquina Head. Of the
187 fish examined, 132 were infected. The following host fishes
yielded the following parasites. New Host records are...
The central nervous system of Phidippus, while comparable to that
of other spiders in most respects, is distinguished by the extraordinary
development of visual processing centers, associated with the
complex visually-directed behavior of these animals.
The primary neuropile of the anterior medial eyes consists of two
distinct columnar synapsing regions....
Animal signaling systems frequently utilize multiple traits to produce and transmit a signal. These system elements may span multiple levels of organization. Functional integration of these traits may be expected to generate concordance in evolutionary pattern among system elements, such that evolutionary change in one system component is correlated with...
Darwin devised the evolutionary theory of sexual selection to account for the manifold extravagances of courtship behaviors and displays. Mating interactions represent a major evolutionary process driving the elaboration, vibrancy, and peculiarity of these courtship traits. For my dissertation research, I strived to elucidate the dynamics that constitute the complex...
My dissertation focuses on the evolutionary forces that have shaped the chemical signaling system of plethodontid salamanders. Pheromones mediate two phases of plethodontid reproduction: mate attraction prior to courtship and female persuasion during courtship. Substrate-borne chemical signals are believed to play an important role in mate attraction for these animals....
Experimental evolution is a tool that allows us to measure changes in populations over time in controlled, novel environments. Microbial evolution experiments use cryopreservation – storage at -80°C in glycerol media – to archive experimental populations. Research with Escherichia coli suggests that cryopreservation conditions can affect cell viability and that...
The benefits of reproduction are clear, but there are also costs. Much is known about the costs of reproduction in females, but only recently have male costs been investigated in any depth. These costs of reproduction may be minimized by appropriately modifying behavior, but there has been little research on...