The metabolism of Strongylocentrotus purpuratus (Stimpson)
was investigated at several levels of urchin organization. Some experiments
were performed with tissues from recently collected
(acclimatized) urchins, Other experiments were performed with tissues
from urchins held at one of two temperatures (acclimated) for
30 days.
Body-component oxygen consumption was measured for bodywall,...
Understanding the dynamics of open marine populations is difficult. Ecological processes may vary with the spatial structure of the habitat, and this variation may subsequently affect demographic rates. In a series of observational and experimental studies in the Bahamas, I examined the roles of emigration, mortality, and predation in the...
Understanding the processes that influence the composition of animal communities is a central goal in ecology. Interactions between established residents and colonizing juveniles that affect the subsequent survival of juveniles may influence community composition. In a series of experiments on coral reef fish communities in the Bahamas and Australia, I...
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...
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...
In a comparison of the mammalian and fish immune systems many similarities and differences are found. While most of the differences occur in the acquired or lymphoid arm of immunity, the nonlymphoid immune systems of fish and mammals share many similarities. For instance, both animal groups use phagocytic neutrophils and...
Recruitment of larvae from the plankton is an important determinant of
community structure in marine systems. In populations of many marine species,
recruitment determines the basic demographic parameters of immigration, emigration,
and reproduction. Moreover, the effect of recruitment as an "ecological subsidy" can
determine the strength of interactions among species...
Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue...