Patterns in the use of gastropod shells by hermit crabs were examined for a complex of hermit crabs inhabiting the Alligator Harbor region of Florida. To assess field use patterns, two sampling techniques, a straight-line transect method and a predation site method, were used. The transect method yielded large animals in relatively undamaged shells of a few gastropod genera, and the results were influenced by habitat. The predation site method yielded a wide size range of individuals in damaged shells of many gastropod species. / Simulated gastropod predation sites attract a variety of hermit crabs. Experiments with simulated predation sites revealed that chemical cues are necessary for location of newly liberated shells. Attraction to a simulated predation site is species specific for hermit crabs and is directly related to the genus of gastropod flesh at the site. In addition, there is a significant positive correlation between amount of flesh at a site and size of crab attracted. These results are discussed in terms of spatial and temporal patterns of hermit crab shell acquisition. / Regardless of the collection method, however, shell use patterns have been evaluated by using empirically derived measures of shell adequacy. Shell adequacy or shell fit has been inferred by using two indices; the shell adequacy index and the utilization efficiency index. Both indices contain statistical biases which render the interpretation of the indices ambiguous. I conclude by describing field and laboratory experiments which demonstrate that determination of shell adequacy is a complex problem which cannot be assessed by simple methods. / Source: Dissertation Abstracts International, Volume: 43-06, Section: B, page: 1721. / Thesis (Ph.D.)--The Florida State University, 1982.

Results of a two year study of colonization of two introduced trees, Quercus acutissima and Castanea crenata, by leaf-mining insects are described in Chapter I. More species of miners completed larval development on Q. acutissima, which has more local native congeners than does C. crenata. However, all miners found on Q. acutissima (subgenus Lepidobalanus) are found on native red oaks (subgenus Erythrobalanus). Leaf-miner density and survivorship were higher on C. crenata than on Q. acutissima, although most of these differences are attributable to two species. Parasitism rates for these species and all miners analyzed together were lower on C. crenata than on Q. acutissima. For some species, reduced parasitism on C. crenata was partially offset by increased predation. Successful colonization of C. crenata by at least one dominant miner may be related to the higher nitrogen content of this host. / In Chapter II, I tested the hypothesis that a significant amount of larval leaf-miner mortality on water oak, Quercus nigra, results from nutritional inadequacy of the host tree. I altered phytochemistry of water oaks with urea- and ammonium-nitrate-fertilization and drought stress. Survivorship of all leaf miners together, and of several dominant species analyzed separately, increased on fertilized trees. Generally, miners responded more to urea-fertilization of trees than to ammonium-nitrate-fertilization. Higher survivorship on fertilized trees was associated with reduced predation. Enhanced larval leaf-miner survivorship correlated with increased densities in 1981, but not in 1980. Leaf-miner survivorship and density increased on drought-stressed trees in both years. / Larvae of two bivoltine species of leaf miners feed only on young, second-flush leaves of their host trees in north Florida. In Chapter III, I show that first-generation larval densities of these species on 30 water oaks is positively correlated with amount of secondary leaf production in 1980 and 1981. During this study, five trees abscised their leaves and reflushed new ones at atypical times of the growing season. Densities of the phenologically specialized miners increased dramatically on these trees only when refoliation coincided with emergence of ovipositing adults. / Source: Dissertation Abstracts International, Volume: 43-06, Section: B, page: 1719. / Thesis (Ph.D.)--The Florida State University, 1982.

Social organization is generally assumed to increase colony efficiency and survival; however, little quantitative information is available to support this assumption. Polymorphism is an important aspect of labor division in colonies of the fire ant, Solenopsis invicta. Our objective was to investigate the effect of fire ant polymorphism on brood production efficiency. / We set up standardized polymorphic colonies with a full range of worker sizes and artificial monomorphic colonies that contained only small, medium or large workers respectively. Polymorphic colonies produced brood at about the same rate as colonies composed of only small workers. Colonies composed of only medium workers produced about half as much brood, and colonies composed of only large workers produced little or no brood at all. This pattern was independent of colony size; however, smaller colonies (0.75 g) produced almost twice as much brood per gram of workers as larger colonies (3.0 g). Additional experiments revealed that the size of workers in the artificial monomorphic colonies affected all stages of brood rearing. Large workers not only inhibited the development of early and late instar larvae but also reduced the queen's oviposition rate. / Energetic brood production efficiency was determined by dividing the grams of brood produced per unit time by the energetic costs expended for the maintenance and production of each worker size class. Worker maintenance costs were estimated from respiration, while production costs were determined from the caloric content of worker tissue divided by their average longevity. Worker respiration per milligram body weight decreased about 40% as body size increased. Large workers lived about 50% longer than small workers and contained 7% more energy per milligram of tissue. Energetic efficiency in polymorphic colonies was approximately 10% higher than in colonies composed of only small workers. In other words, when food supplies are limiting, polymorphism may offer a slight advantage in brood production. / Source: Dissertation Abstracts International, Volume: 45-02, Section: B, page: 0452. / Thesis (Ph.D.)--The Florida State University, 1984.

Seasonal fluctuations of benthic macrofauna (> 500 (mu)m) in the oligohaline East Bay region of the Apalachicola estuary were examined. Multivariate analyses of long-term (42 - 72 months) data from five soft-bottom stations identified three physico-chemical variables (river flow, water temperature and salinity) that were correlated with abundances of dominant macrofaunal species (six polychaetes and one amphipod). However, among station inconsistencies in the responses of these species to environmental variables suggested that additional factors, such as biotic interactions, are important. / Macrofaunal densities peaked during winter months, followed by a rapid decline during late winter/spring. Minimum densities occurred during the summer. The spring decline coincided with an influx of bottom-feeding fishes (Leiostomus xanthurus and Micropogonias undulatus). To test the hypothesis that these fishes were responsible for macrofaunal reduction, predator exclusion experiments were conducted at two unvegetated shallow subtidal East Bay stations. A preliminary study was conducted to design cages (mesh size = 6mm) that produced minimal physical and chemical artifacts. These were used with two-sided controls and uncaged controls in short-term (two month) exclusion experiments to test the effects of bottom-feeding fishes in the spring and Penaeus setiferus in the fall. During 1980, large motile predators were not important in regulating the densities of most macrofaunal species. Densities of L. xanthurus and P. setiferus were lower than in previous years. Despite reduced abundance of bottom-feeding fishes, macrofaunal densities still declined during late winter/spring. Three polychaetes, Mediomastus ambiseta, Streblospio benedicti and Hobsonia florida, accounted for a considerable portion of the late winter reduction in density. Recruitment data from defaunated sediments revealed a low abundance of H. florida and S. benedicti larvae, and virtually no M. ambiseta larvae, in the spring. Thus, lack of larval recruitment contributed to the decline of these short-lived species. It is postulated that increased river flow and lowered salinities during late winter/spring may contribute to the decline of macrofaunal densities by reducing larval recruitment. / Source: Dissertation Abstracts International, Volume: 43-06, Section: B, page: 1723. / Thesis (Ph.D.)--The Florida State University, 1982.

A thirteen month study was conducted in the coastal grassbeds of Apalachee Bay, Florida, to assess the influence of macrophyte species composition and biomass on distribution patterns of plant-associated crustacean assemblages. Crustaceans were collected from a variety of macrophyte-related habitats, including shoots of the seagrasses Thalassia testudinum and Halodule wrightii, large and small bare areas among grass shoots and several macroalgal species with differing morphologies. / Abundance per gram dry weight of Thalassia, species richness and composition of Thalassia-associated crustaceans were similar between sampling sites, yet individuals/m('2) varied significantly. A strong positive correlation was observed between crustacean density and above-ground Thalassia biomass. Comparison of seasonal patterns in faunal abundance between sites suggested differences in crustacean numbers were influenced by plant standing crop, timing of major reproductive effort and seagrass-mediated predation. / Within-site faunal comparison of bare areas and two seagrasses indicated that crustacean abundance and species richness were similar between vegetated substrata and were significantly higher than unvegetated microhabitats. Animals densities, as well as the proportion of epifauna, increased with increasing plant biomass. Generally, crustacean species composition was similar among microhabitats, while differences were noted in relative abundances of certain species. / Significant differences in abundance per gram dry weight were observed among macroalgal species with the highly complex leafy and foliose forms hosting greatest numbers of individuals. Crustacean species richness and composition were similar among algae yet differences were found in the relative abundances of species. Significant abundance-plant weight, species-plant weight and species-abundance relationships were observed for macroalgal crustaceans. Abundance explained most of the variation in species number with plant weight contributing only a small but significant amount. Although macroalgae hosted greater abundances per gram dry plant weight than Thalassia, the relative contribution of macroalgal crustaceans to total faunal density was small and dependent upon the biomass of algae within the grassbeds. / Source: Dissertation Abstracts International, Volume: 43-09, Section: B, page: 2792. / Thesis (Ph.D.)--The Florida State University, 1982.

Using an experimental approach, I have elucidated the role of competition among Heliconiinae larvae in Puerto Rico. I used field cages to control predators and parasitoids while otherwise simulating natural conditions. By vegetatively reproducing Passiflora, I controlled for secondary compounds and other genetically influenced traits. To detect negative interactions I measured pupal weights and larval survivorship. Weight is highly correlated with wing length, with no sexual dimorphism for weight. Larval density and food quantity manipulations demonstrated that six or more individuals of Heliconius charitonius L. or Dryas julia Fab. intraspecifically compete when restricted to 600 cm('2) or less of food plant. Interspecific competition occurred at a density of six of each species. Larval development of H. charitonius is faster with a mean of 13.5 days while D. julia takes 21.5 days; consequently, in my cages, H. charitonius was the superior competitor. / One year of observation at two climatically distinct forests, Guanica (dry) and Cambalache (wet), shows variations in the relative density and distribution of heliconians and Passiflora. Guanica's distinct precipitation-induced seasonality is affected by unpredictable tropical storms; consequently abiotic factors are significant determinants of heliconian distribution and abundance. At Guanica, Passifloras are conspicuously clumped while at Cambalache, their densities are higher. Resource partitioning of new and old plant parts was observed only at Cambalache Forest; otherwise no habitat or plant species partitioning was observed. Although 72% of ovipositing females select large enough plants for their larvae to complete development at Cambalache, only 30% did so at Guanica. Even though observed predation and parasitism were low, disappearance of immatures was high, around 65%. / Comparing experimental results to field observations, I found no interspecific competition and insignificant intraspecific competition at Cambalache. At Guanica, where larvae depend on new growth, which occurs in distinct pulses, intra- and interspecific competition occurred in 38% of the observed plants. However, since adults are patchily distributed, island-wide competitive exclusion of any of the species is unlikely. / Source: Dissertation Abstracts International, Volume: 44-06, Section: B, page: 1708. / Thesis (Ph.D.)--The Florida State University, 1983.

I used approximatley 10,000 records from the North American Nest Record Card Program, over 2000 records from the Western Foundation of Vertebrate Zoology, and nearly 1000 records from Canadian sources to obtain data on the phenology of the nesting season and clutch size of a widespread altricial bird, the Red-winged Blackbird (Agelaius phoeniceus L.). I assess the compatability of nest record cards and clutch collection slips, for estimating nesting phenology and clutch size for the redwing and give suggestions for improving nest record. / My approach to the study of geographic variation in clutch size has been to use large data sets to map patterns of variation in life history traits, look at the relationship of single variables as predictors of clutch size, and then use all variables in a multiple regression model. I examine four hypotheses that have been proposed to account for geographic variation in clutch size: daylength, density-dependent food limitation, food availability independent of density, and the "eggs-in-one-basket" hypothesis. The variables used to predict clutch size were latitude, longitude, length of the breeding season, intraspecific local abundance, and 5 climatic variables. / Clutch size of the redwing varies in a complex pattern in North America. Mean clutch size ranges from 2.77 in Costa Rica to 4.30 in Alaska. The daylength hypothesis is generally supported, because latitude is the most important predictor in the multiple regression model. However, clutch size also varies from east to west. The density-dependent food limitation hypothesis is not supported because local abundance is not a good predictor of mean clutch size and annual migration is not taken into account. The "eggs-in-one-basket" hypothesis is not strongly supported because redwings have multiple broods at high and middle latitudes. However, the length of the breeding season is retained as a predictor variable in the most conservative multiple regression model. My results are most consistent with the hypothesis that geographic variation in clutch size is related to large-scale patterns of variation in food availability. / Source: Dissertation Abstracts International, Volume: 47-07, Section: B, page: 2739. / Thesis (Ph.D.)--The Florida State University, 1986.

I studied factors affecting recruitment of the gorgonian Leptogorgia virgulata and the compound ascidian Aplidium stellatum onto a subtidal limestone outcropping. The recruitment of L. virgulata was significantly reduced by the presence of sand. The relative abundance of animals that recruited into three experimental treatments did not vary over a one year period. Transplant experiments showed that buried colonies grow rapidly, raising new polyps out of the sand. The experimental results successfully predicted the spatial pattern of L. virgulata recruitment on natural surfaces. Other experiments showed that recruitment is significantly reduced by the presence of benthic algae, but is not affected by the exclusion of large fish predators or the removal of established adult colonies. The results emphasize the importance of microhabitat variation in controlling the spatial pattern of recruitment. / Microhabitat also affected recruitment of the compound ascidian Aplidium stellatum. Almost half of the recruits appeared on vertical surfaces, which are rare in the field. In the lab, larvae settled on vertical surfaces with a two to one preference, regardless of how much vertical surface was offered in a particular treatment. However, this preference was too weak to solely account for the field pattern, suggesting differential mortality of newly-settled animals on horizontal surfaces. Temporal patterns of recruitment were associated with the presence of larvae in mature colonies. The presence of larvae correlated with egg numbers and water temperature. / Source: Dissertation Abstracts International, Volume: 47-01, Section: B, page: 0049. / Thesis (Ph.D.)--The Florida State University, 1985.

Our knowledge of the reproductive dynamics of many economically important marine fish species is remarkably poor. This limits our ability to assess and manage the effects of exploitation on their reproductive potential. The Gulf Black Sea Bass Centropristis striata melana is a temperate serranid that contributes to both recreational and commercial fisheries in the state of Florida, however, the reproductive dynamics of this species is not well understood. To fill this gap, I conducted a fisheries-independent survey to explore the spatial and demographic scales of spawning populations in the northeastern Gulf of Mexico. To ensure effective and non-biased sampling, I assessed gear type and fish behavior sampling biases for the Gulf Black Sea Bass. Baited fish traps and hook-and-line were equally selective for fish size, however, hook-and-line had a higher catch efficiency. Body size was strongly correlated to social dominance in the Gulf Black Sea Bass, however, larger individuals in the population were not more susceptible to hook-and-line gears. These results indicated that hook-and-line was the optimal sampling method with relatively high efficiency and low sampling bias. Using hook-an-line fishery-independent surveys, I assessed the spatial and temporal dynamics of the Gulf Black Sea Bass spawning populations to test whether spawning populations were consistent across spawning habitats and describe demographic trends in spawning. Spawning populations were not consistent across available spawning habitat and displayed a high degree of spatial variability over scales of no more than 10 kilometers. These patterns were likely influenced by juvenile recruitment rates. Demography was a clear factor in the timing of reproduction as the proportion and average size of females and males significantly changed over the course of the spawning season. Larger females began spawning earlier in the spawning season and larger males were present on spawning habitats for longer periods. Overall, the findings of this study highlighted the important roles of spatial and demographic variation in the reproduction of the Gulf Black Sea Bass, and warrant future investigation due to their implications into the conservation and management of this economically important fishery. / A Thesis submitted to the Department of Biological Science in partial fulfillment of the Master of Science. / Summer Semester 2017. / July 18, 2017. / Behavioral Selectivity, Black Sea Bass, Demography, Fish, Reproductive Dynamics, Spawning Populations / Includes bibliographical references. / Felicia C. Coleman, Professor Directing Thesis; Emily DuVal, Committee Member; Joseph Travis, Committee Member.

Source: Dissertation Abstracts International, Volume: 40-09, Section: B, page: 4103. / Thesis (Ph.D.)--The Florida State University, 1979.