Marine Biology Commons^™

A Response Surface Investigation Of The Larval Tolerances Of Three Spionid Polychaetes To Temperature, Salinity And Food Concentration, Alan Louis Hillyard

University of the Pacific Theses and Dissertations

Response surface techniques were used to investigate the tolerances of the planktonic larvae of three spionid polychaetes to a variety of temperature and salinity combinations. Two of the spionids were morphologically very similar members of the genus Boccar.dia., B. proboscidea and B. columbiana which occupy nearly identical geographic ranges. The other was Polydora giardi a common coinhabitant with B. columbiana. In addition a third independent parameter, food concentration, was added to the study of B. columbiana and P. giardi.

The larvae of the two Boccardia species were extremely euryhaline, in marked contrast to those of Polydora giardi which were confined …

The Effects Of Predation And Sediment Reworking By The Maldanid Polychaete Axiothella Rubrocincta (Johnson) On Benthic Littoral Microalgae Assemblages, Gary Scott Shusta

University of the Pacific Theses and Dissertations

The taxonomic composition of the diatom assemblages inhabiting the substrate on the mudflat, and the effects of a cohabiting deposit-feeding invertebrate on the diatom assemblage structure are the subjects of this paper. While pelagic diatoms have received considerable attention in the literature to date, comparatively little is known about the ecology and distribution of benthic diatoms are known to be cosmopolitan in their distributions (Alee, 1950). These plants have been found to be opportunistic species in that they are quick to respond to relatively small perturbations in physical conditions. It has also been demonstrated that distinct associations of diatoms exist …

Biological Aspects Of Speciation In Three Sympatric Euzonus Species At Dillon Beach, California (Polychaeta: Opheliidae), Steven Rhoads Parke

University of the Pacific Theses and Dissertations

In the present study, information concerning morphology, ecology, fertilization and larval development of three sympatric species of Eusonus is presented. Morphological similarities are reviewed in part I. These similarities correspond with significant lack of variation found in larval development (part IV). Despite these similarities, as well as the ability to cross fertilize their species, the ecological and reproductive isolating mechanisms presented in part II and II provide a positive indication of the existence of three biologically distinct species. A comparative discussion reviews the efficacy of morphological criteria in differentiating the three closely related Euzonus species.

The Functional Morphology And Ecology Of Chone Mollis, Dale Brian Bonar

University of the Pacific Theses and Dissertations

Chone mollis occurs in large numbers in Tomales Bay and is an ecologically important infaunal member of the bay community. As with most marine communities, very little work has been done with individual species of the community. The present study of C. mollis is a contribution towards an understanding of the community as an ecological unit.

This study investigates the structure and function of the tube; tube-building habits; burrowing and locomotion; external anatomy; feeding; and internal anatomy of the muscular, skeletal, vascular, excretory, reproductive, and alimentary systems of C. mollis.