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We hypothesize that the different limu kohu lineages occupy distinct habitats from each other, and presence of a lineage type could act as an indicator of habitat quality. Preliminary data has been collected on water quality (salinity, turbidity, pH, light levels, and temperature), water motion, and benthic community structure for areas with limu kohu populations on the southeast and east shores of O’ahu. When comparing the habitat data to the limu kohu genotype distribution within each site, the data suggests that the habitat choice amongst lineages may be linked to turbidity and water motion. Lineage 2 and 4 can persist in more turbid and still conditions while lineage 1 solely survives in clearer water with higher levels of water motion. We aim to utilize more sensitive equipment in an effort to reveal patterns with increased detail and reproducible results.
BODY MASS CHANGES AND EXPRESSION OF DEIODINASE TYPE 1 IN NATURAL-FASTING MALE
NORTHERN ELEPHANT SEALSDebby Lee, Rudy Ortiz.
University of California, Merced, Merced, CA.
Deiodinase Type 1 (DI1) converts thyroid hormones (TH) thyroxine (T4) to triiodothyronine (T3) which are essential to mammals that undergo long term fasting. During food deprivation, DI1 activity is increased to raise the monodeiodination of the inner ring to promote the production of reverse T3 (rT3), which suppresses cellular metabolism to protect the organism from energetic burdens imposed during periods of reduced energy intake. T3 and T4 promote basal metabolism in mammals, but its levels and functions are typically suppressed with prolonged fasting. TH plasma concentrations were measured in adult male northern elephant seals to better understand DI1 activity over a natural fasting period. To address our hypothesis that natural fasting in elephant seals promotes body mass loss and stimulates an increase in DI1, we measured body mass and plasma concentrations of rT3, free T3 (fT3), total T3 (tT3), free T4, and total T4 (tT4) in adult male elephant seals (n = 10) over 12 weeks of fasting. Males lost an average of 29% body mass. Fasting did not alter the concentrations of plasma thyroid hormone rT3, fT3, and tT4. However fT4 increased (0.25 ± 0.03ng/dL to 0.78 ± 0.08ng/dL) suggesting that there is an increased potential for TH-mediated cellular effects. Conversely, tT3 decreased (63 ± 5 ng/mL to 50 ± 4ng/mL) between early and late fasting suggesting that DI2 or DI3 may be contributing to the dynamic changes in TH metabolism. Overall, these findings reveal unconventional mechanisms of TH activity regulation and metabolism associated with prolonged food deprivation in a fasting-adapted mammal.
ELUCIDATING THE RESPONSE OF A TOXIC DINOFLAGELLATE TO CO2-INDUCED PH VARIATIONSMaria Nunez1, Rachel Golda2, Tawnya Peterson2, Joseph Needoba2.
Texas Tech University, Lubbock, TX, 2Oregon Health & Science University, Beaverton, OR.
1 Harmful algal blooms (HABs) result from the rapid growth of phytoplankton that can be harmful to human or environmental health. Alexandrium catenella is a marine HAB dinoflagellate that produces saxitoxin, a powerful neurotoxin responsible for paralytic shellfish poisoning. Ocean acidification (OA) is the lowering of ocean pH due
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to the absorption of excess anthropogenic CO2. It is known that OA has a negative effect on calcifying organisms, though its effect on HABs, specifically dinoflagellates, is unknown. Previous studies show that a decrease in pH has a negative effect on dinoflagellate growth. It is also known that a variety of stressors increase dinoflagellate toxin production. However, no studies have investigated if pH stress will have the same effect. The main focus of this study is to determine the effect of pH on toxin production. For this study, we grew batch cultures of A. catenella at 7 different pH levels between 7.0 and 9.0. A continuous culture/chemostat system was used to keep the cultures at a constant pH and pCO2 concentrations. Growth was determined using fluorometry and cell counts, and efficiency of photosystem II was measured using pulse-amplitude modulated (PAM) fluorometry. Cell stress and saxitoxin production will be measured using reactive oxygen species (ROS) assays and enzyme-linked immunosorbent assays (ELISA), respectively. Our preliminary results show that, compared to controls at both high (9.0) and low (7.0) pHs, A.
catenella showed a lower growth rate. Also, significant variations from optimal pH have a negative effect on efficiency of photosystem II (PSII).
CHARACTERIZATION OF VIBRIOPHAGE DOUGLAS 12A4 AND ITS ROLE IN THE EUPRYMNA-VIBRIOSYMBIOSIS Eric Jimmie, Michele Nishiguchi.
New Mexico State University, Las Cruces, NM.
Bacteriophages are viruses that infect bacteria, and they have a major role in microbial evolution by transferring genetic material between non-related hosts. This transfer mechanism, termed transduction, is common among freeliving bacteria and their viruses, but has yet to be explored in symbiotic bacteria found in particular eukaryotic hosts.
Therefore, we have used the sepiolid squid (Mollusca-Sepiolidae)-Vibrio fischeri mutualism as a model to investigate whether bacteriophages have a role in maintaining beneficial associations. To determine whether free-living or symbiotic V. fischeri are subject to phage infection, a Vibrio-specific bacteriophage was isolated from a water sample taken from the coast of Ipswich, Massachusetts. This bacteriophage, named Vibriophage douglas 12A4 was found to infect free living V. fischeri strain 12A4. Adsorption rate, burst size, and replication time were measured to compare this particular phage to other marine bacteriophages that are common among γ-proteobacteria. Through spot plate testing, a number of symbiotic and free-living V. fischeri were evaluated as potential hosts for the bacteriophage.
Other members of the Vibrionaceae family were also examined by spot plate assays to determine the extent of specificity of this bacteriophage. Additionally, the morphology and relative size of Vibriophage douglas 12A4 were measured using transmission electron microscopy (TEM) to determine its family classification. Thus, by characterizing Vibriophage douglas 12A4 and its relationship with V. fischeri, we can better understand what role bacteriophages have in establishing the Euprymna-Vibrio symbiosis.
SEX RATIOS OF DEEP-SEA CHONDRICHTHYANS WITH NOTES ON REPRODUCTIVE STRATEGIES AND
SEXUAL MATURITYMatthew Lawson1, Paul Clerkin2, David Ebert2.
California State University, Monterey Bay, Seaside, CA, 2Moss Landing Marine Laboratories, Moss Landing, CA.
1 Chondrichthyans were collected from 500m to 1500m deep along the Madagascar Ridge, Southern Indian Ocean, on the commercial trawler F/V Will Watch, from February to April 2012. Approximately 2,400 chondrichthyan specimens were examined comprising 13 genera. Morphometric data recording for approximately 400 specimens and vertebrae centra were removed from 225 of the specimens for aging studies. Length and genetic data were collected at sea with representative examples of each species saved and returned to Moss Landing Marine Laboratories for standard morphometric data. Data were also collected on sex ratios, reproductive status, and maturity status. Males and females were identified to species with total length and sex of each individual recorded. Male maturity was estimated by clasper calcification by length, and female maturity was estimated by oviducal gland width, oocyte width, and/ or whether females were gravid. Notable sex male:female ratios of species (Apristurus 1:1, Etmopterus 1:2.3, and Dalatius 7:133) while total length at sexual maturity and reproductive strategies were considered: i.e., oviparity seen in Apristurus, viviparity in various squaloids, and oophagy in Pseudotriakis. This study is important in understanding deep-sea organismal dynamics. It is contributing to National Science Foundation’s Assembling the Tree of Life program, a collaboration with the College of Charleston, to better understand the phylogenetic relationships and origins of all organisms.
Hawaii at Manoa, Honoulu, HI.
Understanding the difference in water quality among various marine habitats is important in monitoring their biological populations. Marine organisms are stratified by varying water quality parameters and metabolic processes. Therefore, establishing a set of typical water quality parameters, such as temperature, pH, salinity and amount of dissolved oxygen, is a practical set of information to have when monitoring marine habitats. Diurnal changes of key water quality parameters with a focus on pH were examined in 6 coral reef communities: 1) offshore Moku O Lo‘e windward reef, 2) windward shallow fore-reef, 3) leeward shallow lagoon, 4) leeward sand flat, 5) lagoon macro-algal mat, and 6) mangrove habitat. The water parameters of each habitat, and their diurnal changes, were monitored using a sonde, an environment monitoring instrument. The pH of seawater in each habitat was also determined using spectrophotometric techniques. Resulting data describe the diurnal changes resulting from physical and biological processes that influence each habitat. The offshore waters show only slight changes in pH, temperature, salinity, and dissolved oxygen. In contrast, the high metabolic rate of coral reef organisms, shallow water, and restricted water circulation resulted in extreme differences in the inshore habitats over the daily cycle. Observing the diurnal cycles of various marine habitats assists in the understanding of their basic biology. This research can be applied to marine environment conservation.
BENEFITS TO INTERTIDAL MARINE GASTROPODS BY CANOPY FORMING ALGAEJafaeth Gomez1, Scottie Henderson2, Jennifer L. Burnaford3.
University of Washington, Friday Harbor, WA, 2Cerritos College, Cerritos, CA, 3California State University, Fullerton, 1 Fullerton, CA.
Intertidal gastropods experience different threats during high and low tides. During low tide, they are at risk of damage from high temperatures and death from predation by birds. At high tide, they may encounter a sea star predator. We hypothesized that seaweed canopies provide two distinct benefits at low tide for the limpet Lottia scutum: shade relief from high temperatures and refugia from bird predation. We predicted that being in the shade at low tide would allow limpets to quickly escape from sea star predators when the tide came in, but that spending low tide in the sun would delay this escape response because high temperatures can inhibit physiological processes. Additionally, we predicted that limpets under the canopy at low tide would experience less bird predation than exposed limpets. To test the effect of location and low tide temperature on the response to sea star predators, we exposed limpets to a sea star after a simulated warm or cool low tide and quantified the amount of time the limpet spent in different escape response components. To test the effect of low tide location on the susceptibility to bird predation, we tethered limpets under seaweed canopies and on open rock. In preliminary studies, after cool low tides, limpets responded immediately to sea stars, but after warm low tides, the escape response was delayed by more than 5 minutes. Knowing the extent to which intertidal animals depend on seaweed canopies can potentially help us understand the effects of long-term climate change.
DIFFERENTIAL DEVELOPMENT OF CASSIOPEIA XAMACHANA UPON INFECTION WITH MULTIPLE
SYMBIODINIUM SPECIESMyriam Zavalza, Siobhan Kelly, Erika Diaz-Almeyda, Mónica Medina.
School of Natural Sciences, University of California, Merced, Merced, CA.
The upside-down jellyfish Cassiopeia xamachana establishes an endosymbiotic relationship with Symbiodinium during it scyphistoma life stage. This symbiotic relationship is common among cnidarians. In the case of C.
xamachana, this symbiosis is mandatory for its development into a sexually mature medusa. However, the dinoflagellate genus Symbiodinium is very diverse, containing several species that can potentially have unique effects on the stages of metamorphosis. During the maturation of C. xamachana, scyphistomae (the sessile polyp stage) were infected with 3 species of Symbiodinium: S. minitum (culture code Mf 1.05b, clade B1) isolated from the coral Montastrea faveolata; S. microadriaticum (culture code CassKB8, clade A1) isolated from C. xamachana; and Symbiodinium sp. (culture code CassEL1, clade A3) also isolated from C. xamachana. The process of infection and
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subsequent metamorphosis into symbiotic ephyrae (the juvenile pelagic stage) was visually represented with a photo record displaying the presence of Symbiodinium cells within the scyphistomae. Differences in rate of Symbiodinium endocytosis were observed when infected with these different species suggesting that the host preferentially selected the species it most commonly associates with, S. microadriaticum. Assessment of the development and metamorphosis and the study of such unique relationships could suggest the potential of the C. xamachana as a model organism for future research endeavors.
ROLE OF BB0019 IN THE PATHO-PHYSIOLOGY OF BORRELIA BURGDORFERIMaria Hinojosa, Cindy Schulheiss, Trever Smith, Janakiram Seshu.
University of Texas at San Antonio, San Antonio, TX.