With a dramatic decrease of biodiversity as a result of the increase in exploitation of marine ecosystems, the establishment of marine protected areas (MPAs) serves as an important means of protecting those resources. Although there is support for the effectiveness of these MPAs and MPA networks, there is room for improvement in terms of MPA management and design. For example, a better understanding of the dispersal dynamics of targeted species across these MPAs will serve as a more accurate means of reserve as well as fisheries management. While there have been many methods used to determine the larval dispersal of a certain species, parentage analysis is becoming the most robust. In this thesis, I attempt to determine the patterns of self-recruitment and larval dispersal of the Longfin Grouper (Epinephelus quoyanus) in one focal marine reserve within the Great Keppel Island group through the method of parentage. For this, I developed 14 microsatellite markers and with those, genotyped 610 adults as well as 478 juveniles from the study site. These genotypes allowed me to assign offspring to their potential parents, which then allowed me to measure the self-recruitment, local retention as well as larval dispersal percentages of this species from and within the reserve. My results indicate that there is 32% local retention to the reserve while 68% of the assigned juveniles were dispersed to other areas (4% of which dispersed to another reserve). Previous studies conducted in the same area showed higher reserve self-recruitment rates for both Plectropomus maculatus (~30%) and Lutjanus carponotatus (64%) despite their similar life history traits. The results from this study add to the growing evidence that dispersal patterns cannot be generalized across marine systems or even between species within a single system.

Comachara cadburyi Franclemont has benn classified as a sarrothripine (Noctuidae), lithosiine (Arctiidae), and afridine (Nolidae). Larval morphology and behavior indicate a close phylogenetic relationship with Polygrammate hebraeicum Hübner, an acronictine noctuid. The egg and larva of Comachara are described and illustrated with line drawings and scanning electron micrographs. Photographs of last instars of both Comachara and Polygrammate are provided. Larval feeding and pupation habits of C. cadburyi are briefly described and compared with those of Polygrammate. Larvae of both Polygrammate and Comachara exhibit a dramatic coloration change in the last instar, transitioning from a green phase to a mottled, steely gray form. As the color change progresses, the larva ceases feeding and enters a wandering phase, during which it seeks out wood in which to pupate. Interpretation of L group setal homologies on the ninth abdominal segment is briefly addressed. Comachara provides a poignant example of the importance of immatures in elucidating phylogeny - adult features of Comachara misled a number of the twentieth century century's finest lepidopterists.

Early work on the reproductive seasonality of corals in the Red Sea suggested that corals exhibit temporal reproductive isolation, unlike on the Great Barrier Reef where many species spawn in synchrony. More recent work has however shown high synchrony in the maturity of gametes in Acropora species, suggesting multi-specific spawning is likely to occur in the Red Sea. In this thesis I investigate the patterns of coral reproduction in the central Red Sea. The spawning season in the central Red Sea lasts four months, from April to July and spawning occurs on nights around the full moon. During this period Acropora species show a peak of spawning in April, with some species spawning again in May. The level of synchrony, quantified with a spawning synchrony index, is comparable to other locations where multi-specific spawning has been reported. Observations over two consecutive years show that the synchrony of spawning was lower in spring 2012 than in spring 2011, and thus that spawning patterns are variable from one year to the other. Coral settlement patterns on artificial substrata confirmed a main spawning season in the spring but also supported reproductive data suggesting that some Porites spawn in October-November. Settlement was studied over 2.5 years on a reef, which had suffered recently from high mortality after a local bleaching event. Settlement appeared low but post-bleaching studies from other locations indicated similar abundances and showed that recruits generally did not increase until 5 years after the bleaching event. Abundance of juvenile corals however started to increase significantly three years after the bleaching. Successful recruitment, although low suggests that the coral assemblage on the affected reef will most likely recover as long as it is not affected by another disturbance.

The field of marine population connectivity is receiving growing attention from ecologists worldwide. The degree to which metapopulations are connected via larval dispersal has vital ramifications for demographic and evolutionary dynamics and largely determines the way we manage threatened coastal ecosystems. Here we addressed different questions relating to connectivity by integrating direct and indirect genetic approaches over different spatial and ecological scales in a coral reef fish in the Red Sea. We developed 35 novel microsatellite loci for our study organism the two-band anemonefish Amphiprion bicinctus (Rüppel 1830), which served as the basis of the following approaches. First, we collected nearly one thousand samples of A. bicinctus from 19 locations across 1500 km along the Saudi Arabian coast to infer population genetic structure. Genetic variability along the northern and central coast was weak, but showed a significant break at approximately 20°N. Implementing a model of isolation by environment with chlorophyll-a concentrations and geographic distance as predictors we were able to explain over 90% of the genetic variability in the data (R2 = 0.92). For the second approach we sampled 311 (c. 99%) putative parents and 172 juveniles at an isolated reef, Quita al Girsh (QG), to estimate self-recruitment using genetic parentage analysis. Additionally we collected 176 juveniles at surrounding locations to estimate larval dispersal from QG and ran a biophysical dispersal model of the system with real5 time climatological forcing. In concordance with model predictions, we found a complete lack (c. 0.5%) of self-recruitment over two sampling periods within our study system, thus presenting the first empirical evidence for a largely open reef fish population. Lastly, to conceptualize different hypotheses regarding the underlying processes and mechanisms of self-recruitment versus long-distance dispersal in marine organisms with pelagic larval stages, I introduce and discuss the concept of “origin effects”, providing the theoretical background to some of the questions that have arisen during this research. Overall, this thesis has generated significant new insights into the patterns of coral reef fish connectivity, specifically for the Red Sea, where such information has previously been scarce.

<p> The development of Na+ and Ca++ transport, ammonia excretion, and respiration in larval rainbow trout were studied over the period of yolk sac absorption and shortly after the onset of exogenous feeding. The gills and the yolk sac epithelium of larvae were examined for any indication of the presence of mitochondria-rich cells and/ or Na-K-ATPase activity. </p> <p> Whole body Na+ content of the larvae increased throughout yolk sac absorption and after the onset of exogenous feeding. During this period there was an increase in Na+ influx, efflux, transporter capacity Umax> and transporter affinity (Km). Jmax increased 4.6 times during yolk sac absorption, and increased another 2.8 times 248 degree·days after the onset of exogenous feeding. Km decreased over the first 168 degree·days and stayed constant for the remainder of the experimental period. The gills were the primary site of Na+ efflux. Na+ accumulation from the water began the first day post hatch. </p> <p> Ca++ transport capacity increased throughout yolk sac absorption, but then decreased after the onset of exogenous feeding. Jmaxca++ exhibited a 15.5 fold increase over 257 degree·days, which then decreased to 30% of that value after exogenous feeding commenced. There was a 162 fold increase in Ca++ Km over yolk sac absorption, which then decreased 15.6 times after the onset of exogenous feeding. Whole body Ca++ began to increase approximately 200 degree·days post-hatch and exhibited a large increase after the onset of exogenous feeding. It is possible that during yolk sac absorption the larvae does not begin to accumulate Ca++ from the external environment until its internal reserves are depleted, and with the onset of feeding the larvae then obtains its Ca++ from its diet. </p> <p> Ammonia excretion in larval trout increased 3.6 times over yolk sac absorption, and increased another 2.8 times after exogenous feeding commenced. There was no evidence of a link between Na+ uptake and NJ-:4+ excretion in larval fish as NJ-:4+ excretion was not stimulated in response to increasing external Na+ concentrations. Measurements of the ammonium concentration at different surfaces of the larvae revealed a larger ammonium concentration next to the gills than next to the yolk sac and skin. This may indicate that the gills are the primary site for ammonia excretion in the larval fish. </p> <P> Initially, branchial and cutaneous surfaces contributes to respiration, but as the gills grow and develop and the yolk sac decreases in size and the skin thickens, the contribution of the gills to this function increases. </p> <p> The gills of first day hatchlings are comprised of gill arches and filaments. Lamellae do not begin to develop until a few days after hatching. The gill filaments contain mitochondria-rich cells and have Na-K-ATPase activity as determined through binding of the fluorescent dye anthroylouabain. The yolk sac epithelium contained cells with concentrated regions of mitochondria, but significant Na-K-ATPase activity was not detected when compared to branchial staining. </p> / Thesis / Master of Science (MSc)

This dissertation compares immune responses of resistant and susceptible sheep to infection with Haemonchus contortus during the peri-parturient period and larval stage of infection. Identification of immunological events resulting in parasite resistance in St. Croix hair sheep may provide better targets for differential gene expression analysis and eventual discovery of selectable markers for parasite resistance. Antibody levels of hair ewes and composite Dorset x Finnsheep-Rambouillet wool ewes were measured during breeding and again after parturition. Results demonstrated that hair ewes had higher levels immunoglobulin-A after infection and maintained a higher level of circulating antigen-specific antibody when compared to wool ewes. To characterize immune responses to the larval stage of infection, hair and wool lambs were sacrificed at 0, 3, 5, and 7 d after infection with H. contortus. Neutrophil migration to abomasal mucosa and lymph node development were higher in hair sheep than in wool sheep. Gene expression analysis indicated no difference in the abomasal lymph node as both breeds expressed a general T-helper cell type 2 (TH2) response. However, profound differences in TH2 responses were observed in the abomasal mucosa, where hair sheep expressed more IL-4, -13 and -33 than wool sheep. These data thus document the presence of immunological differences between the breeds. Immune responses to larval parasite infection in wool sheep are generally suppressed and may increase the magnitude and duration of infection whereas immune responses to larval infection in hair sheep was more robust and more strongly polarized towards a TH2 / Ph. D.

Anglers unlawfully introduced gizzard shad Dorosoma cepedianum into Claytor Lake, Virginia in the late 1980s, apparently with the intention of improving the sportfishery by adding an additional clupeid prey resource. This study examined the trophic interactions between larval shad and resident zooplanktivorous fishes, in an attempt to discover the potential for trophic competition and negative impacts to these fish species. Ichthyoplankton sampling in 1997 and 1998 showed that peak abundances of larval shad overlapped temporally and spatially with both larval Lepomis spp. and larval alewife Alosa pseudoharengus. Peak larval shad density (0.04-0.06 fish/m3) was two to three orders of magnitude less than that reported from other reservoir systems, slightly less than that of larval alewife in Claytor Lake (0.05-0.07 fish/m3), and significantly less than that of larval Lepomis spp. in Claytor Lake (0.28-0.51 fish/m3). Diet overlap values indicated potential resource overlap among all three larval taxa. Diet of larval shad did not overlap with that of either age-0 Micropterus spp. or adult alewife. All species of limnetic larvae examined showed feeding preferences for Diaphanosoma and copepod nauplii. Crustacean zooplankton densities did not respond negatively to peak larval fish abundances, and never dropped below 250-400 organisms/L. In Claytor Lake, the impact of trophic competition with larval gizzard shad on other zooplanktivores currently appears to be minimized by low densities of larval shad and abundant crustacean zooplankton. / Master of Science

Annual bluegrass weevil (Listronotus maculicollis Kirby) (Coleoptera: Curculionidae) (ABW) is a major pest of annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis stolonifera L.) on golf courses in the northeastern United States. The asynchronous life cycle makes managing ABW difficult, putting emphasis on scouting to achieve accurate insecticide timing and acceptable control. Little is known about the biology and management of ABW in Virginia's more temperate climate. Reported cases of ABW resistance to pyrethroids (IRAC Group 3) continues to grow in the northeast, yet no pyrethroid-resistance cases have been reported in Virginia outside of the metropolitan Washington, D.C. For this thesis, I confirmed the widespread distribution of ABW across Virginia with a survey of golf course superintendents. Two golf courses in southwestern Virginia were monitored weekly during the 2019 and 2020 growing seasons to determine the seasonal biology of ABW within this region. These data suggest that overwintering ABW emerge much earlier than described in the northeast, with adult weevil activity beginning in late February or early March. I observed three complete ABW generations, with a potential fourth generation. Soil plugs from the same two golf courses were used to compare the salt floatation and Berlese-Tullgren funnel methods of larval extraction. The methods were highly correlated (R2 = 0.7856), suggesting either method is appropriate for ABW larval extraction. Bioassays conducted on adult ABW from the same two golf courses showed that field rate concentrations of the pyrethroid bifenthrin showed variable mortality ranging from 20% to 80% suggesting the presence of resistance genes in the population. A 100-fold rate of bifenthrin resulted in 100% mortality of ABW, however. Because cross-resistance has been reported among northeastern ABW populations, the common insecticide active ingredients chlorpyrifos (IRAC Group 1B: Organophosphate), trichlorfon (IRAC Group 1B: Organophosphate), λ-cyhalothrin (IRAC Group 3: Pyrethroid), α-cypermethrin (IRAC Group 3: Pyrethroid), imidacloprid (IRAC Group 4A: Neonicotinoid), and spinosad (IRAC Group 5: Spinosyn), were tested on ABW adults. In another bioassay, two organophosphates, trichlorfon and chlorpyrifos, resulted in significantly higher ABW mortality rates than all other labeled insecticides (P < 0.0001). Two other larvicides, spinosad and α-cypermethrin, also exhibited adult control, an important factor to consider for ABW management and preventing pyrethroid-resistance. These results provide valuable insight into the seasonal biology and management of ABW in Virginia and direction for further investigation into these populations. / Master of Science in Life Sciences / Annual bluegrass weevil (Listronotus maculicollis Kirby) (ABW) is a tiny, but damaging insect pest of cool-season golf course turfgrasses in the northeastern United States. As pest populations have spread southward, ABW has become an emerging pest in Virginia. The objectives of this thesis were to 1) determine the geographic distribution and seasonal biology of ABW in Virginia, 2) compare two methods for extracting ABW larvae from turf cores in order to estimate larval densities, and 3) to assess the susceptibility of ABW to various insecticides commonly used by golf course superintendents. A survey of golf course superintendents in 2019 revealed widespread prevalence of ABW across Virginia, particularly in areas growing predominantly cool-season turfgrasses. Two golf courses in southwestern Virginia were monitored weekly during the growing seasons of 2019 and 2020 to determine the seasonal biology of ABW. Data suggest that overwintering ABW emerge much earlier than reported in the northeast, with adult weevil activity beginning in late February or early March compared to April in the northeast. In addition, I detected three complete ABW generations, with a possible fourth generation occurring. Soil plugs from two golf courses were used to compare a heat extraction method using a Berlese-Tullgren funnel with the traditional salt float method for extraction of ABW larvae. The two methods extracted similar numbers of ABW larvae suggesting that either method is appropriate for ABW larval extraction. Adult ABW from the same two golf courses were collected and subjected to the pyrethroid insecticide bifenthrin at 0.128 kg ai ha-1 (field application rate), 1.28 kg ai ha-1 (10-fold rate), 12.8 kg ai ha-1 (100-fold rate), along with a water control. Results indicated that the field application rate of bifenthrin killed > 50% but <90% of ABW adults, suggesting that some resistance may be present in the population. A concentration of 100-fold bifenthrin field rate killed 100% of tested individuals, suggesting that widescale field resistance to pyrethroids is likely not present. Because cross-resistance has been reported among northeastern ABW populations, the common insecticide active ingredients chlorpyrifos (IRAC Group 1B: Organophosphate), trichlorfon (IRAC Group 1B: Organophosphate), λ-cyhalothrin (IRAC Group 3: Pyrethroid), α-cypermethrin (IRAC Group 3: Pyrethroid), imidacloprid (IRAC Group 4A: Neonicotinoid), and spinosad (IRAC Group 5: Spinosyn), were tested on ABW adults from the same two golf courses. Two organophosphates, trichlorfon, a larvicide, and chlorpyrifos resulted in significantly higher ABW mortality rates than all other active ingredients (P < 0.0001). Two other larvicides, spinosad and α-cypermethrin, also exhibited adult control, an important factor to consider when attempting to manage ABW and preventing resistance to pyrethroids. Our results provide valuable insight into the seasonal biology and management of ABW in Virginia and direction for further investigation into these populations.

Chronic toxicity of zinc to Pimephales promelas was estimated by conducting replicate static and static-renewal short-term embryo-larval tests and static-renewal seven-day larval tests. The two test methods were highly reproducible. Daily renewal of test solutions had little effect on the toxicity of zinc, however, the stage of development at which exposure was initiated affected the sensitivity of the toxic endpoints measured. The most sensitive and reproducible endpoint in the embryo-larval tests was survival of viable (non-deformed) larvae and in the seven-day larval test was growth of the larvae, which was slightly more sensitive than the embryo-larval test endpoint. The estimated MATC of 0.18 and 0.15 mg/L mean total and mean soluble zinc, respectively, compared well with published results. Because of its advantages and similar sensitivity, the short-term embryo-larval test was recommended for estimating chronic toxicity.

A variabilidade espacial e temporal do suprimento larval pode influenciar fortemente as taxas de recrutamento em populações de invertebrados marinhos do entre marés, e, assim, determinar os padrões de abundância e distribuição de adultos. No entanto, o comportamento de larvas antes do assentamento, e a sua condição fisiológica, podem também desempenhar um papel importante. Há vários fatores que influenciam a qualidade fisiológica de uma larva, sendo um deles o efeito materno, ou seja, a forma como os recursos são manipulados pelas mães para produzir sua prole, especialmente como afeta a fecundidade. Outro fator importante é o estado trófico do ambiente onde estágios iniciais se desenvolvem em estágios finais pré-competentes. No entanto, pouco se sabe sobre a relação entre esses dois processos e se a variabilidade natural das condições da costa realmente provoca uma pior qualidade no desempenho juvenil e nas taxas de recrutamento. Neste estudo nós analisamos se os processos que afetam a qualidade embrionária e larval são independentes ou interativas, e também se as condições ambientais ao longo de uma costa subtropical pode mediar tendências de qualidade de larvas à mesoescala e também determinar padrões de distribuição de invertebrados sésseis do entre marés. Usamos a craca Chthamalus bisinuatus como modelo biológico, e experimentos de laboratório e de campo foram realizados para explorar a relação de diversas variáveis ambientais nos padrões de distribuição destes cirripédios. Testamos também se as oscilações naturais na disponibilidade de alimento determinam padrões espaciais e temporais da qualidade da larva produzida e os efeitos da disponibilidade de alimento para as mães e para os seus descendentes na qualidade do estágio larval final deste organismo. Os resultados obtidos nessa tese apontam para a importância da disponibilidade de alimento na coluna d\'água em determinar padrões de abundância e tamanho dos organismos adultos, bem como a relação com o grau de exposição à ação de ondas na manutenção de populações adultas. Concluímos também que mudanças sazonais na produtividade primária tem um efeito na fecundidade e qualidade da larva produzida ao longo do ano por esses cirripédios. Finalmente pudemos demonstrar que pequenas alterações na quantidade de alimento fornecida à mães e larvas de Chthamalus são suficiente para provocar plasticidade de alguns tratos larvais importantes para os processos e sucesso do recrutamento destes organismos. / Spatial and temporal variability of larval supply can strongly influence the recruitment rates in populations of marine intertidal invertebrates, and thus determine the abundance and distribution patterns of adults. However, the behavior of larvae prior to settlement, and its physiological condition, may also play an important role. There are several factors that influence the physiological quality of a larva, one of them being maternal effects, that is, the way resources are allocated by mothers to produce their offspring, especially the way it affects fecundity. Another important factor is the trophic state of the environment where early stages develop into competent pre-final stages. However, little is known about the relationship between these two processes and if the natural variability of coastal conditions actually causes poorer quality in young performance and recruitment rates. In this study we analyzed the processes affecting embryonic and larval quality and if they are independent or interactive, and also if the environmental conditions along a subtropical coast can mediate trends in quality larvae to mesoscale and also determine sessile intertidal invertebrates distribution patterns. We used the barnacle Chthamalus bisinuatus as a biological model, and laboratory and field experiments were conducted to explore the relationship of various environmental variables in the patterns of distribution of these barnacles. We tested also if natural fluctuations in food availability determine spatial and temporal patterns of larvae quality produced and the effects of food availability for mothers and their descendants in the quality of the final larval stage of this organisms. The results obtained in this thesis point to the importance of the food availability in the water column in determining patterns of abundance and size of adult organisms, and the relationship with the degree of exposure to wave action in the maintenance of adult populations. We also conclude that seasonal changes in primary productivity has an effect on fecundity and quality of the larvae produced throughout the year by those barnacles. Finally we were able to demonstrate that small changes in the amount of food provided to mothers and larvae Chthamalus are enough to cause plasticity of some important larval traits which impacts the processes and success of recruitment in these organisms.