Marine Biology Commons^™

Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos

University of the Pacific Theses and Dissertations

Marine mammals play an important role in ecosystem stability. However, anthropogenic activity is compounding pressure on many already vulnerable populations. A potential consequence of anthropogenic disturbance is physiological stress, which can impact metabolism, immunity, and reproduction, especially if it occurs repeatedly. Previous studies on marine mammals have focused on acute stress, but the impacts of repeated stress are poorly understood. Due to its accessibility on land during haul-outs, the northern elephant seal (Mirounga angustirostris) is a good system in which to study the effects of stress in marine mammals. Stress stimulates the release of glucocorticoid hormones, primarily cortisol. Elevated cortisol …

Impacts Of Plastic Pollution On A Pelagic Marine Mammal, The Northern Elephant Seal, Lauren M. Kashiwabara

University of the Pacific Theses and Dissertations

As plastic pollution increases, top marine predators such as marine mammals are becoming increasingly susceptible to plastic particles and their additives. Plastic particles have been found in gastrointestinal tracts and scat of many marine mammals, and quantifying plastic pollution in those that are pelagic can provide insight into plastic pollution in mesopelagic ecosystems that are just beginning to be analyzed. Adapting well-developed laboratory techniques for microplastic (MP) isolation (i.e. density separation and chemical digestion), I isolated MPs from the scat of the deepest diving pinniped, the northern elephant seal (NES), and found that100% of scat samples (n=11) contained high counts …

How Do They Do It? Using Omics Approaches To Explore Metabolic Responses Associated With Hypoxia And Exercise Tolerance In The Deepest Diving Pinniped, Elizabeth R. Piotrowski

University of the Pacific Theses and Dissertations

Marine mammals such as northern elephant seals (NES) routinely experience hypoxemia and ischemia-reperfusion events to many tissues during deep dives with no apparent adverse effects. Adaptations to diving include increased antioxidants and elevated oxygen storage capacity associated with high hemoprotein content in blood and muscle. Despite experiencing decreased oxygen tensions during diving, NES likely rely on the mobilization of large lipids stores and catabolism of fatty acids to provide energy to exercising muscle while diving. To identify potential regulatory mechanisms that may underly hypoxia and exercise tolerance in diving mammals, this study used system-wide approaches to characterize changes in genes …

Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade

University of the Pacific Theses and Dissertations

Increasing anthropogenic disturbance in marine ecosystems such as fishing, oil-drilling, and noise pollution can have detrimental effects on the reproduction and survival of apex predators such as marine mammals. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in increased circulating glucocorticoid (GCs) hormones, which alter expression of target genes encoding metabolic enzymes and other mediators of stress. Prolonged HPA axis stimulation may increase catabolism of nutrient stores and suppress immune and reproductive functions, impacting the fitness of marine mammals. GCs measurements are used to identify wild animals experiencing stress. However, these measurements may not be sensitive enough to distinguish between an …

Blubber Transcriptome And Proteome Responses To Repeated Adrenocorticotropic Hormone Administration In A Marine Mammal, Jared Deyarmin

University of the Pacific Theses and Dissertations

Chronic physiological stress impacts animal fitness by catabolizing metabolic stores and suppressing reproduction and immunity. This can be especially deleterious for capital breeding carnivores, such as marine mammals, which rely on lipid stores accrued during intensive foraging to sustain prolonged periods of fasting associated with reproduction. Therefore, chronic stress may cause a decrease in fitness in these animals, leading to population declines and potentially detrimental shifts in food web dynamics as a result. However, the impacts and indicators of chronic stress in animals are currently poorly understood. To identify downstream mediators of repeated stress responses in marine mammals, adrenocorticotropic hormone …

The Relationship Of Sexual Dimorphism And Differential Predation To Sex Ratio In Leptochelia Dubia (Crustacea: Tanaidacea), Joseph Anthony Mendoza

University of the Pacific Theses and Dissertations

Leptochelia dubia is a dioecious tube-building tanais, which broods its young and exhibits marked sexual dimorphism. The species is widely distributed in the Pacific, Atlantic, Mediterranean and Indian Oceans, but to date there are no published accounts of its ecology. L. dubia is one of the most abundant of the small Crustacea in Tomales Bay, where it may attain densities of 30,000/m² in soft bottom communities.

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 …

Structure, Function, And Functional Morphology Of Mitra Idae Melvill 1893 And M. Catalinae Dall 1920, Terry L. West

University of the Pacific Theses and Dissertations

The morphology of the proboscis--particularly the epiproboscis, the feeding behavior, the function(s) of the epiproboscis, and the functional morphology of the epiproboscis, were studied in Mitra idea Melville and fi. catalinae Dall (Gastropoda: Neogastropoda; Mitridae.

In M. idae, the epiproboscis is an extensible muscular J-shaped rod which curves under the odontophore, and lies parallel to the longitudinal axis of the proboscis. A muscular external sheath encloses that portion of the epiproboscis which lies within the proboscis haemacoel; an invaginated muscular-epithelial internal sheath covers the ventral part of the epiproboscis. The dorsal part of the epiproboscis consists principally of longitudinal muscle; …

The Effect Of Body Size And Algal Suspension Density On Filtration Rate And Assimilation Efficiency Of Three Marine Mussels, Mytilus Californianus, Mytilus Edulis And Perna Canaliculus With Consideration Of The Growth Of Each Species, Thomas B. Mccormick Iii

University of the Pacific Theses and Dissertations

Rates of uptake of organic and inorganic suspended particulate material by suspension feeding bivalve molluscs have been studied since the nineteenth century (see Viallanes, 1892) . Studies have investigated molluscan feeding mechanisms, filtration capabilities, food assimilation and metabolism. The bulk of this work has been directed towards the mussel Mytilus edulis Linnaeus and the oyster Crassostrea virginica Gmelin (see reviews by Galtsoff, 1964; Ali, 1970; Jorgensen, 1975; 1976; and Winter, 1978). More recently the growth of mussels, oysters, clams and scallops has been quantitatively studied in controlled systems to assess the biological potential of these molluscs in an aquaculture setting …

The Structure Of Macrofaunal Assemblages Inhabiting An Intertidal Sandflat In Tomales Bay, California, Jay Charles Carroll

University of the Pacific Theses and Dissertations

Confronted with a diverse sandflat community of interacting organisms and a spectrum of physical forces, a meaningful community analysis should begin with a description of physical characteristics and faunal distributions over time. The functional importance of certain species in the community should then be investigated by using both field and laboratory experiments. Consequently, the purpose of this research was twofold: (1) to apply the methods of similarity and gradient analysis to describe the faunal gradation on an intertidal sandflat and; (2) use these data to design a predator exclusion field experiment aimed at assessing the effects of shorebird, crab and …

Experimental Studies Of Interactions Between Zostera Marina And The Associated Benthic Fauna, David Marshall Penny

University of the Pacific Theses and Dissertations

The objectives of the present study are to: (1) Describe the macro-invertebrate species composition and seasonal changes in abundance of the benthic infauna within an eelgrass bed; (2) Observe what immediate effects occur to the benthic community as a result of experimental removal of eelgrass plants from plants within the Zostera bed; (3) Measure the seasonal variation of eelgrass turion length over an annual cycle and determine its correlation to biomass (dry weight); (4) Examine, by means of field experiments, the importance of incident solar irradiation in affecting the seasonal growth of Zostera; and (5) Determine the relationship, if any, …

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 …

Calcification And Productivity In A Dominant Shallow Water Reef Building Coral, Acropora Palmata (Lamarck), Elizabeth H. Gladfelter

University of the Pacific Theses and Dissertations

Coral reefs are "constructional physiographic features of tropical seas consisting fundamentally of a rigid calcareous framework made up mainly of the interlocked and encrusting skeletons of reef-building (hermatypic) corals (Wells,1957). The principal organisms responsible for the construction of modern day coral reefs, the stony corals, comprise the cnidarian order Scleractinia, which is closely allied to the sea anemones (Actinaria). Individual polyps secrete a calcium carbonate skeletal cup (calyx) beneath the basal epidermis. In most coral species the polyps remain connected by living tissue forming a colony and calcium carbonate is deposited beneath the basal epidermis of the entire colony, thereby …

The Ecology Of Some Harpacticoid Copepods Of A California Sand Flat, David R. Williams

University of the Pacific Theses and Dissertations

The main purpose of this study is to describe the population ecology of eight species of harpacticoid copepods over a period of one year with emphasis on the effects of physical interactions and biotic factors on these populations. The species were: Amphiascopsis sintus (Claus) 1866, Stenhelia (D.) oblonga Lang, 1965, Heterolaphote variables Lang, 1965, Ectinosoma melaniceps Boek ? var. T. Scott, 1902, Paralophonte subterraneas Lang, 1965, Tisbe furcata (Baird) 1837, Diasaccus spinatus Cambell, 1929 and Parathelestris bulbiseta Cambell?.

The Structure Of Experimental Clastic-Substrate Marine Communities, Wayne Aloysius Evans

University of the Pacific Theses and Dissertations

It is hypothesized that difference between containers and between sediments will produce structural differences in the resulting communities by intensifying competition for resources, and by excluding certain classes of predators. It is also hypothesized that the level of the effect of container, substrate, and time on community structures will be dependent on tidal level.

Paine (1969) and Dayton (1972) have demonstrated that the structure of some communities is largely determined by the effects of foundation, or keystone, species. It is suggested that the structure of classic-substrate communities may be determined similarly.

Reproductive Ecology And Population Dynamics Of Two Sympatric Species Of Macoma (Bivalvia), John Gibson Rae Iii

University of the Pacific Theses and Dissertations

Populations of the sympatric intertidal bivalves, Macoma secta and M. nasuta are compared as to reproductive ecology and population dynamics. Histological examination of seasonal gonadal changes indicate that both species undergo dormancy in the winter months and rapid gamete proliferation in the spring. However, the timing of spawning differs. The M. secta population synchronously spawned in August while the M. nasuta population spawned lightly in late spring and more heavily in the fall. Fecundity estimates indicate M. nasuta adds 140% of winter weight in gametes and M. secta only adds 43% of winter weight in gametes. Spat fall was detected …

Effect Of Thermal Stress On Larvae Of Patiria Miniata (Brandt) Including Studies On Induction Of Spawning, Development And Larval Tagging, Kenneth A. Simon

University of the Pacific Theses and Dissertations

It has been estimated by the Department of the Interior that by 1985 nearly one-quarter of all surface water in the United States will be used in removal of waste heat produced in electric generation. This will involve subjecting tremendous quantities of plankton to rapid fluctuations in temperature. The biological effect of such treatment on primary productivity and composition of zooplankton populations is not fully understood. To date little published information is available on the effect of rapid temperature fluctuations on plankton. Such temperatures are the result of heat exchange found in the cooling system of a steam-generating electric station. …

Fitness Theory And Aspects Of Behavioral Ecology In Two Sympatric Pacurus Species At Dillon Beach, California : Decapoda, Anomura), John Erickson Warner

University of the Pacific Theses and Dissertations

In the present study, aspects of the behavior and ecology of two sympathetic intertidal hermit crabs, Pagurus hirsutiusculus and Pagurus samuelis were studied with the intention of expanding the use of fitness set analysis to other species, particularly extending studies over the entire breeding season.

Population Ecology Of The Littoral Fringe Gastropod Littorina Planaxis In Northern California, Russell James Schmitt

University of the Pacific Theses and Dissertations

Life history patterns of individual organisms are the result of natural selection and should be correlated with particular physical and biological characteristics of habitats in which they live. The littoral fringe is known to be the most severe physical habitat in the intertidal zone, and it is expected that organisms in it should have population characteristics associated with selective response to physical adversity rather than biological interaction. Ecological studies of populations of Littorina planaxis were made in the Dillon Beach and Bodega Head areas. The study localities differed principally in extent of wave exposure rather than geographical location.

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.

Models Of Primary Productivity In The Oceans, William Yi-Been Chang

University of the Pacific Theses and Dissertations

A general mathematical equation relating variables affecting primary production has been developed to predict changes .in the vertical distribution of primary production in the oceans. The model is tested and shown to fit empirical observations from diverse oceanic areas.

The Ecological Life History And Feeding Biology Of Batillaria Zonalis (Bruguière), Robert Bruce Whitlatch

University of the Pacific Theses and Dissertations

In the present study, aspects of the ecological life history of Batillaria zonalis (Brugiere) has been investigated for a period of two years. Trends in population dynamics and aspects of its biology in two salt marsh localities are described. Results of studies of the feeding biology of the sympatric population of Batillaria and Cerithidea californica (an “ecological equivalent” of Batillaria (Macdonald, 1969) and their interaction with diatoms are reported with reference to food-resource partitioning. The results are discussed within the context of problems of testing hypotheses about diversity and stability in salt marsh communities. Although these basic theoretical questions cannot …

Larval Development And Feeding Ecology Of Hermissenda Crassicornis (Eschscholtz) And Aeolidia Papillosa (Linnaeus), Leslie G. Williams

University of the Pacific Theses and Dissertations

Thompson (1967) defines three developmental types for Opisthobranchia with representative nudibranchs in each category. The types are: 1.) planktotrophic larvae which are obligatory plankton feeders prior to progressive metamorphosis, 2.) lecithotrophic larvae which may feed on the plankton, but do not need to do so in order to metamorphose, 3.) direct development which results in hatching of a post veliger, benthic juvenile.

Tardy (1970) feels that Thompson's Type 3 development is artificial. Thus, he incorporates direct development into the lecithotrophic developmental type. Tardy then proposes a classification of metamorphic types based on larval shell type (Thompson, 1961) and on larval …

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.

Reproductive Biology Of Thais Emarginata (Deshayes, 1839) And Thais Canaliculata (Dulcos, 1832), Roy Seamands Houston

University of the Pacific Theses and Dissertations

Thais emarginata (Deshayes, 1839) and Thais canaliculata (Dulcos, 1832), are two common Pacific coast gastropods (Family: Muricidae). T. emarginata is found in semi-protected rocky areas from Alaska to Baja California, while T. canaliaulata occurs in quiet bays from Alaska to Monterey Bay, California (Ricketts and Calvin, 1966). Both species occur on rocks and jetties where they can be seen feeding upon barnacles and young mussels. Despite the abundance of these species their reproductive biology has not been examined.

In the present study, the following aspects of the reproductive biology of T. emarginata and T. canalieulata are presented: Relationship of gonadal …

A Discussion Of The Cytherinae (Ostracoda) With Description Of Two New Species, Leslie Edward Watling

University of the Pacific Theses and Dissertations

This paper is concerned with the description of two new ostracod species, and the discussion of their affinities with other species in the subfamily Cytherinae. In this discussion reference is made to the morphological features of several genera. At this point it must be made clear that although the original type descriptions were used, the author has never seen the type specimens. Thus, all discussion is based on these original descriptions as well as on available supplementary material.

Digenetic Trematodes From Embiotocid Fishes Of Tomales And Bodega Bays, California, Thomas David Rodella

University of the Pacific Theses and Dissertations

The present paper deals solely with parasites of marine fishes of the family Enbiotocidae represented in the American Pacific according to Special Publications no. 2, American Fisheries Society, 1960, by 20 species, all of which are marine except the Tule perch, Hysterocarpus traski (Gibbons) from fresh water. In Tomales and Bodega Bays 174 fishes representing 9 embiotocid species were examined and found to harbor 6 species of digenetic trem todes, including one here in described as new.

Studies On The Gonadal Pigments Of Cryptochiton Stelleri (Middendorff), Robert Eugene Senff

University of the Pacific Theses and Dissertations

The large gumboot chiton, Cryptochiton stelleri, (Middendorf, 1846) annually undergoes a reproductive cycle terminated by spawning in the spring. Cryptochiton stelleri is one of the marine invertebrates which possess carotenoid prognosis. Cryptochiton acquired its carotenoid moiety from the algae upon which it feeds. Following digestion carotenoids are transported to various sites in the body. The mechanisms and routes of this transport, as well as the eventual fate of the carotenoids in nutrition, are unknown. Perhaps storage in the animal occurs because of an inability to eliminate the carotenoids. On the other hand, the presence of carotenoids in the gonads would …

Redescription Of The Adult Water Mite Hydrachna Miliaria And Description Of Its Life History, David Lou Kass

University of the Pacific Theses and Dissertations

During the summer of 1957 the writer became interested in water mites while collecting insects in an unnamed pond (see map in appendix) near Tomales, California. It was noted during that period that specimens of a giant water-bug, Lethocerus americanus Leidy (1847) had many larval mites attached to their ventral sides, and the lack of information concerning these animals and their life histories stimulated interest in investigating the problem detailed in this thesis. This work was begun in the summer of 1957 and has continued through the summer of 1959 and 1960.

Due to the lack of information and lack …

A Physiological Comparison Of Isopods In The Transition From A Marine To A Terrestrial Habitat : With Notes On Their Morphology And Behavior, Gary John Brusca

University of the Pacific Theses and Dissertations

This study is of five species of isopods common to the Dillon Beach area, each of which represents a different level in the transition toward land life. Cirolana harfordi was used as a completely marine form. Idothea (Pentidotea) wosnesenskii represents a step toward land life as it inhabits an area uncovered by most low tides. Ligia occidentalis is found in the splash zone, receiving spray from the action of the surf. This illustrates another, higher, level in the transition. Alloniscus perconvexus was the fourth species studied. It is commonly found burrowed in the sand in the area of the berm, …