Marine Biology Commons^™

Recreational Diving And Hawksbill Sea Turtles (Eretmochelys Imbricata) In A Marine Protected Area, Christian Hayes

Loma Linda University Electronic Theses, Dissertations & Projects

Recreational diving is a form of ecotourism that is traditionally viewed as an ecologically sustainable activity prompting increased awareness for the marine environment. Recent studies, however, indicate that recreational diving may cause unintended behavioral changes in marine macrofauna. Few studies, however, have specifically investigated the effects of recreational diving on sea turtles. I conducted in-water observations and turtle sightings surveys from June 9 to August 21, 2014, in Roatán, Honduras, to determine if differences in dive site use and diver behavior alter the behavior of critically endangered hawksbill sea turtles (Eretmochelys imbricata) in a marine protected area (MPA). I found …

Reproductive Ecology And Hatchling Behavior Of Olive Ridley Sea Turtles In Honduras, Noemi Duran Royo

Loma Linda University Electronic Theses, Dissertations & Projects

In this dissertation, I investigated the reproductive ecology and hatchling behavior of the olive ridley (Lepidochelys olivacea) sea turtle population nesting in Pacific Honduras. I begin by reviewing olive ridley reproduction, human use of this species, and past and present conservation on nesting beaches. I also propose a conservation strategy to improve nesting beach conservation programs in developing countries. In the first of four empirical studies, I used microsatellite markers to assess multiple paternity levels of the Honduran population, and found evidence for multiple paternity in 75% of the nests examined. This rate, higher than expected for a population of …

Behavior And Physiology Of Hermit Crabs During Burial: Shell Abandonment And Lactate Accumulation, Janelle Allison Shives

Loma Linda University Electronic Theses, Dissertations & Projects

Organisms living in the intertidal zone must adapt to environmental and physical stressors. One physical stressor that these organisms may face, and that may require specific behavioral and physiological responses, is burial by sediment. In this thesis I report the results of experiments in which I subjected the intertidal hermit crab, Pagurus samuelis, to burial and analyzed aspects of subsequent behavior and physiology. In the first set of experiments, hermit crabs were buried with the shell aperture facing either up or down, and at one of three depths (2, 4, or 6 cm). The factors hermit crab weight, shell …

Temporal Fatty Acid Fluctuations Of Pachygrapsus Crassipes In Southern California, April Dawn Sjoboen

Loma Linda University Electronic Theses, Dissertations & Projects

The current investigation identified fatty acids (FAs) and quantified total and specific FA concentrations in the striped shore crab, Pachygrapsus crassipes. I examined changes in the abundance of individual FAs and FA saturation categories (saturated, monounsaturated, polyunsaturated) over months and between sexes. Fatty acid fluctuations were compared with reported temperatures from a location near the collection site to determine whether temperature significantly contributed to these changes. The abundances of palmitoleic acid, palmitic acid, and docosahexaenoic acid (DHA) were found to fluctuate significantly on a monthly basis, with a higher abundance in warm months than in cold months. This fluctuation appeared …

Responses To Salinity Of Color Polymorphs In Two Populations Of The Sea Star, Pisaster Achraceus, Viren Johann Perumal

Loma Linda University Electronic Theses, Dissertations & Projects

Pisaster ochraceus was analyzed to determine if varying salinities, animal color, or location affect the physiology of these sea stars. The three responses analyzed were aerobic respiration, ammonia excretion, and self-righting. The tested variables included two different color morphs (orange and purple) of P. ochraceus, two different locations (open coast and inland straits) in Washington State, and three salinities (22, 30, and 40 psu).

Wet mass-specific oxygen consumption rates were not significantly affected by color, location, or salinity, and Dry mass-specific oxygen consumption rates showed no significant differences for main effects, but a three-way interaction was identified. Similarly, ammonia …

Comparison Of The Barnacle, Balanus Amphitrite, In Different Environments, Katsura Mastuda

Loma Linda University Electronic Theses, Dissertations & Projects

The Salton Sea is a saline lake located centrally in the Colorado Desert, California. Salinity as well as nutrients of the Sea have been increasing since 1907, thus it is currently facing ecological collapse. The barnacle, Balanus amphitrite saltonensis at the Salton Sea was once thought to be a subspecies of B. amphitrite due to distinctive morphological differences between populations at the Sea and San Diego Bay. However, only one subspecies, Balanus amphitrite amphitrite, currently exists based on genetic studies. My study investigates physiological, survival, and morphological differences of B. amphitrite populations from the Salton Sea and San Diego …

Macrogeographic Genetic Structure In Acanthephyra Curtirostris (Oplophoridae), John Russell Scarbrough

Loma Linda University Electronic Theses, Dissertations & Projects

The vast oceanic living space on our planet is occupied by zooplankton species long assumed to be widespread and genetically undifferentiated across their species range. Recently, however, data from sensitive DNA-based molecular markers has shown that many cryptic species exist in the sea and that marine zooplankton species may be more genetically structured than previously thought. In the oceanic environment, the deep-sea appears to be particularly homogeneous with few observable barriers to gene flow and it is also less studied. DNA-based investigations of genetic diversity in the deep-sea are needed to help determine the spatial scale over which species and …

Effect Of Pollution On Genetic Diversity In The Southern California Bight, Xiao Li Ma

Loma Linda University Electronic Theses, Dissertations & Projects

Two intertidal invertebrate species, M galloprovincialis and Balanus glandula, were collected from seven different bay sites along the Southern California coast to test if environmental contamination is associated with the decrease of genetic diversity at the population level. Collections were made at three relatively pristine "clean" sites and four "impacted" sites which were exposed to heavy industrial or boating activity and which had previously, been identified as having measurable levels of pollution. The "Comet" assay (Single Cell Gel electrophoresis) was performed to measure single-strand DNA breaks in mussels at several of the sites in order to confirm differing impacts …

Ventilation Behavior Of The Mantis Shrimp, Hemisquilla Ensigera Californiensis In Hypoxic Burrows, Tamara L. Richter

Loma Linda University Electronic Theses, Dissertations & Projects

The burrow-dwelling mantis shrimp, Hemisquilla ensigera californiensis, is an environmentally challenged marine species due to the fact it inhabits burrows located beneath the surface of the sediment where oxygen pressure is low and easily depleted. This experiment revealed that burrow oxygen pressure (pO₂) is frequently hypoxic and can become anoxic. Average pO₂ within the burrow is between 40-50 mm Hg and may drop below 10 mm Hg even if the burrow isn't capped. When capped, p0₂ rapidly drops to 0 mm Hg within two hours. Low pO₂ does not result in decreased animal activity, …

Oxyconformity In Burrow-Dwelling Crustaceans : Aerobic Metabolism Of Hemisquilla Ensigera Californiensis, Leandra P. Peters

Loma Linda University Electronic Theses, Dissertations & Projects

Hemisquilla ensigera califomiensis is an active burrow-dwelling stomatopod crustacean common off the coast of Southern California (Basch and Engle, 1989). In this experiment I measured the typical burrow oxygen level, time taken to deplete the oxygen in an inhabited, capped burrow, and tested the hypothesis that H. ensigera, like other burrow dwellers that have been examined, is an oxyregulator; and that like crustaceans in general, they have only limited anaerobic capabilities. Contrary to expectations, I found that H. ensigera is an oxyconformer or at best a weak oxyregulator, and that the species has substantial anaerobic capacity. Since it was …

The Effects Of Temperature On The Physiology Of Phataria Unifascialis : And Its Implications For The Species' Distribution In The Gulf Of California, Michael Boyce Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Populations of the asteroid Phataria unifascialis were sampled subtidally in the Gulf of California at Loreto, well within the species' distribution, and at Bahia de los Angeles (the Bay of LA), at the northern end of its distribution on several occasions between 1989 and 1991 to determine the influence of water temperature on species' physiology at each location. The starfish was much more abundant at Loreto, and though both locations had similar indices of pyloric caeca and gonad development, the population at Loreto was distinctly separated by depth into a shallow reproducing population and a deeper feeding population. No such …

Chemoreceptors Regulate Discharge Of Microbasic P-Mastigophores In The Sea Anemone, Aiptasia Pallida, Gail E. Muir Giebel

Loma Linda University Electronic Theses, Dissertations & Projects

Recently, using cnida-mediated measurements of adhesive force, Thorington and Hessinger (1984, 1988a, b) identified two different chemoreceptors involved in triggering cnida discharge on the tentacles of the sea anemone, Aiptasia pallida. These two classes of receptors were shown to interact with glycine and N-acetylneuraminic acid (NANA). We now show that the discharge of the microbasic p-mastigophores, one of the three types of cnidae present on the tentacles of A. pallida, is under the controlling influence of these two classes of cnidocyte-associated chemoreceptors. We also demonstrate that the number of discharged microbasic p-mastigophores adhering to the test probes is proportional to …