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Biting has been observed to be an important component of male mating behavior in several elasmobranch species. I observed male biting during courtship and mating in a population of Urolophus halleri, the round stingray, in the Sea of Cortez. Females allow males to bite the posterior and medial edge of their pectoral fin during courtship yet often appear to struggle to dislodge the male after they have been bitten. During mating the male bites the anterior edge of the females' pectoral fin and the female is passive. In response to this biting behavior females have relatively thicker discs than males and males have sexually dimorphic dentition. Larger adult males have relatively smaller yet more sharply curved teeth than smaller males that may allow them to hold on to females better during courtship. Therefore there is the potential for assortative mating based on male dentition and his ability to hold a female.

Indirect effects occur when the interaction between two species is influenced by a third species. Recent empirical and theoretical evidence suggests that indirect effects have important influences on population regulation and community structure. Most studies of indirect effects have examined chains or networks of predation or competition. Indirect effects can also involve other types of interactions, yet their role in structuring communities is rarely considered. One such interaction, biological habitat modification, is ubiquitous in marine habitats, especially through the alteration of sediments or the creation of hard substrates. In soft-bottom habitats, the shells of dead molluscs are important for shelter or attachment of many organisms, and mollusc predators should have strong indirect effects on the community by regulating the availability of these substrates. Because shells are produced by living organisms, their abundance and quality will also be influenced by the dynamics of the mollusc population and by processes that destroy or alter the shells. / I examined the indirect effects of the horse conch (Pleuroploca gigantea), a predatory gastropod, on a suite of fish and invertebrates that use bivalve shells (the pen shell Atrina rigida) as shelters and/or nest sites in St. Joseph Bay, Florida. Exclusion experiments indicated that horse conchs are a major source of Atrina mortality. Experimental additions of new shelters caused an increase in abundance and reproductive activity in three species of fish (two blennies and a clingfish). Increased rates of shell availability caused an increase in reproductive output for both individuals and the local population of Chasmodes saburrae, the Florida blenny, probably because new shells provide a greater surface area for eggs compared to older shells. I used a simulation model, based on measurements of natural variation in Atrina population and shell resource dynamics, to compare the relative effects of horse conch predation and other factors on Chasmodes. Although pen shell density had the strongest effect, horse conch abundance also strongly influenced blenny reproduction. Thus, both the field experiments and the model predict that, by regulating the availability of new shells, the horse conch has a positive indirect effect on reproduction in Chasmodes. / Source: Dissertation Abstracts International, Volume: 57-04, Section: B, page: 2296. / Major Professor: William Herrnkind. / Thesis (Ph.D.)--The Florida State University, 1996.

The purpose of this dissertation was to investigate the usefulness and limitations of radioactive tracers as a tool for the study of microbial-meiofaunal trophic interactions under near-natural conditions. / Three methods of delivering labeled substrates to natural cores of sediments were compared. Slurried sediments disrupted the sedimentary structure and significantly altered uptake of labeled substrates by copepod species. Thus, disruption of sedimentary structure can significantly alter microbial-meiofaunal interactions and influence the results of grazing studies. / The ($\sp3$H) -thymidine technique for measuring bacterial production was evaluated. The metabolic fate of labeled thymidine in a coastal marine sediment was not consistent with assumptions necessary for measuring bacterial production or its consumption by meiofauna. / Microautoradiography was used to demonstrate that sedimentary microalgae and heterotrophic bacteria can be selectively labeled with ($\sp{14}$C) -bicarbonate and labeled organic substrates, respectively. / A study was performed to determine if radioactivity measured in copepods from grazing experiments was the result of ingestion of labeled microorganisms or the result of uptake by non-feeding processes. Uptake of label by copepods from ($\sp{14}$C) -bicarbonate was due almost exclusively to grazing on microalgae. Uptake of label by copepods from ($\sp{14}$C) -acetate, however, resulted from activity by epicuticular bacteria and was not due to ingestion of labeled bacteria. / Considered collectively, the results of these studies indicate that, when nondisruptive methods of label introduction are used, ($\sp{14}$C) -bicarbonate can be used as a reliable tracer of grazing on microalgae. Labeled organic substrates, however, do not appear to be a valid tracer form consumption of heterotrophic bacteria. Specifically, uptake by epicuticular bacteria associated with copepods account for essentially all of the radioactivity that is associated with copepods. / Source: Dissertation Abstracts International, Volume: 50-08, Section: B, page: 3250. / Major Professor: David Thistle. / Thesis (Ph.D.)--The Florida State University, 1989.

Source: Dissertation Abstracts International, Volume: 35-12, Section: B, page: 6005. / Thesis (Ph.D.)--The Florida State University, 1974.

Source: Dissertation Abstracts International, Volume: 38-12, Section: B, page: 5702. / Thesis (Ph.D.)--The Florida State University, 1977.

<p> Very little information is available on the Hawaiian Oyster <i> Dendostrea sandvicensis</i> in regards to its biology and physiology. Efforts were made to better understand the active reproductive season of this oyster by studying the population located in He'eia fish pond in Kaneohe Bay, O`ahu. This study focused on the condition index (CI) and gonadal developmental stage trends, measured from monthly oyster tissue samples from January to December 2009. The relationship between CI and temperature was examined. Results suggest CI is not related to temperature. Further analysis defined a positive correlation for CI and temperature during summer but not in winter. Ranges in CI values were higher in summer than in winter. <i>D. sandvicensis </i> experience a tropical reproductive cycle, as trends related to the gonadal stage indicate. January to March is dominated by maturing gonads. From April to October there is a rise and then steady decline of empty gonads indicating an active reproduction season. From November to December a rise in mature gonads indicate readiness for reproduction and recovery. Empty gonads are present through out the year indicating reproduction happens throughout the year, and peaks in beginning of summer.</p>

<p> Copepod nauplii are important members of the marine planktonic community, and they can be the most abundant component of the microzooplankton. Despite the importance of copepod early life history stages to food web dynamics and carbon flux in the sea, there is a paucity of information about their ecology due to challenges in identifying nauplii to species, and in sampling them quantitatively. I report here on the development and optimization of a new molecular method that uses quantitative PCR (qPCR) to identify and estimate the abundances of nauplii of a common coastal copepod, <i>Parvocalanus crassirostris,</i> in field samples. The following experiments were performed towards this goal: I surveyed the genetic diversity of copepods in the study region, optimized sample treatment for qPCR, developed a size fractionation protocol to separate life stages of the target species, quantified the mitochondrial cytochrome C oxidase subunit I (mtCOI) gene copies in each <i> P. crassirostris</i> life stage, tested the effect of food levels on mtCOI copy number in nauplii, and compared direct counts to qPCR estimates of the target species to validate the qPCR method. The number of mtCOI gene copies in each developmental stage of this species was found to increase by &sim;1.5 orders of magnitude from early nauplii to adult. Food level experiments suggested that mtCOI copy number may be influenced by feeding environment in late naupliar stages. In validation experiments, qPCR estimates were 68 to 130% of the number estimated from direct counts. Both methods had a coefficient of variation of approximately 16%, indicating similar precision across methods. As a field test of the method, daily samples were collected in southern Kane&lsquo;ohe Bay and used to quantify the density <i>P. crassirostris</i> nauplii over a 13-day period in the summer of 2011. The average density of <i> P. crassirostris</i> nauplii in developmental stages NII - NV was found to be 1.5&times;10³ individuals m^-3 over the 13-day period. The qPCR-based method developed here will enable future studies on naupliar ecology in the field, including investigation of food web, population, and community dynamics.</p>

Moored sediment traps intercepted material for approximately one year in the southern Ross Sea, Antarctica. Fecal pellets >100 um in trap samples were classified according to morphology as tabular, ellipsoidal, or cylindrical. The abundance, relatively large size, and high settling velocities of tabular pellets made them the most important pellet type by volume in vertical flux to 250 meters water depth and to the sea floor. Most pellets arrived at the traps in short-lived, high-flux events from the end of January through early March. Numerically, tabular pellets dominated pellet flux to 250 meters, and ellipsoidal pellets dominated pellet flux to the sea floor. This change suggests the presence of an active mid-depth zooplankton community that intercepts and repackages settling material. The different physical properties and settling velocities of the pellet types indicate that changes in pellet producer populations might significantly affect vertical flux and could modify regional biogeochemical cycles.

The term nowcast is used to emphasize that a forecast is being produced for very short lead times, typically 0 to 6 h. Most nowcasting systems use weather radar as the primary tool for forecasting. Modern techniques use computer algorithms to compute these short-term forecasts, and have been shown to have more skill than human forecasters or numerical models alone. Applications of nowcasting span across many industries, with aviation being of particular importance. / The essence of nowcasting can be summarized in two steps: (1) obtain a motion estimate for an existing storm, and (2) advect the current storm using the derived motion estimate. Since the inception of weather radar, nowcasting methods have noticeably improved, particularly with respect to estimating storm motion. However, nowcasting is still largely based on Lagrangian persistence, where the forecast field (i.e. reflectivity) is held constant in the Lagrangian frame. This has been done principally because of the difficulties associated with forecasting storm growth and decay. / In this paper, an attempt is made to incorporate storm growth and decay into the McGill Algorithm for Precipitation Nowcasting by Lagrangian Extrapolation (MAPLE), by using mesoscale parameters to physically constrain the evolution storm systems. The analysis is conducted on a continental scale, over the contiguous United States. The parameters selected for study were equivalent potential temperature (thetae) and convective available potential energy (CAPE), because they have been shown by theory and observations to be directly related to the intensity and duration of storm systems (Zawadzki and Ro 1978 and Zawadzki et al. 1981, 1994). While past studies were based on observations on a local scale, valid on a day-to-day basis, the current work is applied to a continental scale, on an hour-by-hour basis. / Results of the study show little promise for application to nowcasting. No correlations were found between various measures of storm growth/decay and the mesoscale parameters. Several explanations for the results are proposed, which include poor data quality, insufficient sample size and the possibility of a land-surface feedback.