Life Sciences Commons^™

Comparative Reproductive Biology Of Two Florida Pawpaws Asimina Reticulata Chapman And Asimina Tetramera Small, Anne Cheney Cox

FIU Electronic Theses and Dissertations

I investigated the phenology and breeding systems of two Florida endemic pawpaws, Asimina reticulata, widespread in peninsular Florida, and A. tetramera, a federally endangered species limited to two counties on the Atlantic Coastal Ridge. The purpose of this study was to determine if differences contribute to the rarity of Asimina tetramera compared with A. reticulata. The study was conducted in sand pine scrub sites with the largest populations of A. tetramera in the two counties. Flowering seasons differ for the two species. Both species are hermaphroditic and strongly protogynous. Pollination experiments show that neither species is autogamous and the primary …

Determining Interspecific Interactions Between The Dominant Macrophytes Of Tropical, Atlantic Seagrass Meadows, Braxton C. Davis

FIU Electronic Theses and Dissertations

Though often suggested in seagrass literature, interactions between abundant rhizophytic macroalgae and coexisting tropical seagrasses have not been directly examined. Based on a competitive interaction hypothesis, I first tested for negative correlations between species densities over large and small spatial scales. After finding negative correlations, I tested experimentally for a competitive interaction by manipulating the relative densities of the locally dominant seagrass and a representative macroalga. Based on significant growth responses to density manipulations, I demonstrated that these species are likely competing for some limiting resource, possibly nitrogen. This study contributes to a better understanding of processes that dictate community …

The Herpetofauna Of Iwokrama Reserve: A Comparison Of Sampling Methods, Megan Huilan Chen

FIU Electronic Theses and Dissertations

Inventory sampling provides information on assemblage structure and baseline species diversity data for future comparisons. This study explored the efficiency and accuracy of inventory sampling methods for an assemblage of lowland tropical amphibians and reptiles. Data were collected from the Iwokrama International Centre for Rain Forest Conservation and Development in Guyana. Four standard methods (day visual encounter survey, night visual encounter survey, leaf litter plots, and opportunistic collecting) were used to examine assemblage structure. I analyzed these data to look for variation in amphibian and reptile species diversity among different parts of the reserve and different methods. Species diversity varied …

Pollination And Breeding Of Jackfruit (Artocarpus Heterophyllus Lam.) In South Florida, Sherine El-Sawa

FIU Electronic Theses and Dissertations

Jackfruit (Artocarpus heterophyllus Lam.) is a multi-purpose fruit tree, native to tropical Asia. It was introduced to South Florida in the early 1900s but has had little commercial importance. In recent years, there has been an increased interest in jackfruit as a commercial crop in South Florida, but there has been little scientific investigation conducted. The pollination mechanism was not clearly understood. This study focused on jackfruit breeding using 'Dang Rasimi' and 'Cheena' cultivars. Controlled hand-pollinations revealed that both cultivars were not apomictic. Both cultivars set fruit with self-pollination, but seed set and many fruit characters such as size, …

Substructuring In Four Populations Of African Descent, Margarita Teresa Almeida

FIU Electronic Theses and Dissertations

When a suspect's DNA profile is admitted into court as a match to evidence the probability of the perpetrator being another individual must be calculated from database allele frequencies. The two methods used for this calculation are phenotypic frequency and likelihood ratio. Neither of these calculations takes into account substructuring within populations. In these substructured populations the frequency of homozygotes increases and that of heterozygotes usually decreases. The departure from Hardy- Weinberg expectation in a sample population can be estimated using Sewall Wright's F_st statistic. F_st values were calculated in four populations of African descent by comparing allele …

Biology And Use Of Nibbi Heteropsis Flexuosa (Araceae) The Source Of An Aerial Root Fiber Product In Guyana, Bruce Hoffman

FIU Electronic Theses and Dissertations

The aerial roots of Heteropsis flexuosa (Kunth) Bunting, a hemi-epiphyte, are harvested by indigenous communities in Guyana for a developing wicker furniture market. Nibbi roots have potential as a sustainably harvested product, but there is little data to guide management. I examined nibbi biology, harvest response, product yield and use at several forest sites. H. flexuosa is a relatively abundant plant and 35% of trees (≥ 10 cm dbh) in plots were hosts. Stems exhibited mean growth rates of 1-3 cm per month. Aerial roots grew a mean 156 cm per month and some reached maturity within 6 months. With …

Parasexuality And Heterokaryosis In Fusarium Oxysporum Forma Specialis Cubense, Blanca R. Cortes

FIU Electronic Theses and Dissertations

Intra and Inter Vegetative Compatibility Group (VCG) heterokaryon formation was observed in Fusariurn oxysporum f.sp. cubense (Foc). Using the double-pick method to force heterokaryon formation via hyphal anastomosis, 10⁴ pairwise combinations were done between 100 auxotrophic mutants of Foe representing races 1, 2 and 4 in five VCGs. Inter formae speciales heterokaryon formation was also observed on pairings between benomyl resistant Wild Type Testers (WTT) and wild type isolates in 15 VCGs and four different formae speciales. Microconidia analysis of heterokaryons identified both parental phenotypes as well as diploid phenotypes. Colonies with altered and hybrid genotypes were …

Immunocytes Of The Atlantic Bottlenose Dolphin (Tursiops Truncatus) And West Indian Manatee (Trichechus Manatus Latirostris) : Morphologic Characterizations And Correlations Between Healthy And Disease States Under Free-Ranging And Captive Conditions, Gregory D. Bossart

FIU Electronic Theses and Dissertations

Interest in the health of marine mammals has increased due, in part, to the attention given to human impact on the marine environment. Recent mass strandings of the Atlantic bottlenose dolphin (Tursiops truncatus) and rising mortalities of the endangered Florida manatee (Trichechus manatus latirostris) have raised questions on the extent to which pollution, infectious disease, "stress," and captivity influence the immune system of these animals. This study has provided the first in-depth characterization of immunocytes in the peripheral blood of dolphins (n=180) and manatees (n=56). Immunocyte morphology and baseline values were determined in clinically normal animals …

Evidence For The Alternative Pathway Of Complement Activation In The Nurse Shark, Lieneke Cecile Culbreath

FIU Electronic Theses and Dissertations

Complement is activated via two pathways: classical (CCP) and alternative (ACP). The CCP has been demonstrated in the nurse shark. The ACP has not been demonstrated in any cartilagenous fish. Nurse shark serum was evaluated for complement activity by its ability to lyse heterologous erythrocytes. As CCP activity requires calcium and magnesium, activity of shark serum chelated with EGTA (a selective calcium chelator) or EDTA (a chelator of calcium and magnesium) was assessed. Activity remained in serum chelated with EGTA but not EDTA. Furthermore, activity of chelated serum was enhanced by added magnesium. Activation of shark complement by activators of …

Reproductive Ecology Of The Burrowing Owl, Athene Cunicularia Floridana, In Dade And Broward Counties, Florida, Brian Keith Mealey

FIU Electronic Theses and Dissertations

From 1988 to 1990 a study of the reproductive ecology of the burrowing owl was conducted to determine seasonality and reproductive success in Dade and Broward Counties. Reproductive data for each of the three years (1988- 1990) reveal a higher reproductive success rate (54%) for 1990 than 1989 (40%) and 1988 (40%). Owls using previously used burrows had a higher success in fledging young (63%) than newly excavated burrows (19%). T-tests were conducted on several appendage measurements of male and female owls to determine sexual dimorphic traits. Metatarsus lengths of males and females were different (t=2.36, p=0.02). As of 1990,197 …

Population Ecology Of The Bald Eagle (Haliaeetus Leucocephalus) In Florida Bay, Everglades National Park, Florida, 1959-1990, John L. Curnutt

FIU Electronic Theses and Dissertations

Using aerial census techniques, I collected data on the population, reproduction and nesting habits of Bald Eagles in Florida Bay, Florida, for three consecutive breeding seasons (Oct - Mar, 1987 - 1990). For analysis I consolidated my data with those collected by Robertson et al. between 1959 and 1986 for a total of 26 seasons. The breeding population of Bald Eagles in Florida Bay has been stable since censuses began in 1959. However, numbers of subadult eagles in Florida Bay have declined sharply since the early 1960’s. Breeding density was apparently limited by territoriality. Nesting success was positively correlated …

Potential Rates Of Methanogenesis In Peat And Marl Sawgrass Wetlands In The Florida Everglades, Dave S. Bachoon

FIU Electronic Theses and Dissertations

Methanogenesis was studied in soils from two sawgrass wetlands of the Florida Everglades. Marl soils exhibited a significantly higher potential rate of methanogenesis than peat soils. In these wetlands, methanogenesis: (1) decreased rapidly with increasing soil depth, (2) increased at higher temperatures and lower Eh, (3) was stimulated by organic compounds (cellulose, glucose and acetate), and (4) remained unaffected by added ammonium. Lowering the Eh in the peat and marl soils with sulfide or sulfate stimulated methanogenesis. In January 1990, phosphate caused a significant increase in methanogenesis. The potential rates of methanogenesis decreased to undetectable levels when water levels dropped …

Seasonal Activity And Road Mortality Of The Snakes Of The Pa-Hay-Okee Wetlands Of Everglades National Park, Frank S. Bernardino

FIU Electronic Theses and Dissertations

The current study describes the composition and activity of the snake community of the Pa-hay-okee wetlands of Everglades National Park. The study was conducted from January 1987 to January 1989. Sixteen species were observed, with Thamnophis sauritus, Thamnophis sirtalis, Nerodia fasciata pictiventris, and Agkistrodon piscivorus representing 90.2% of the total sample. The seasonal distribution and activity of the snakes were closely related to fluctuations in the water table. Most activity occurred in the winter months as snakes migrated west following the drying water edge of Shark River Slough. Seventy percent of all snakes observed during this study …

The Status And Ecology Of The American Alligator (Alligator Mississippiensis) In Par Pond, Savannah River Site, Laura A. Brandt

FIU Electronic Theses and Dissertations

Par Pond is a man-made 1120 ha cooling reservoir located on the Savannah River Site near Aiken, South Carolina. From 1972-1978 a detailed study on the status of the alligator in Par Pond was conducted by Tom Murphy (unpub. MS thesis Univ. of GA, 1977). Murphy estimated that approximately 110 alligators inhabited Par Pond with an adult (> 1.8 m) to juvenile (< 1.8 m) ratio of (1.8:1), an overall sex ratio of 3.2:1, and an average of only 2.3 nests/yr. The purpose of this study (1986-1989) was to determine the current population size and structure, determine how the population has changed in the last 15 years and to examine growth and survival of juvenile alligators.

Data were collected by monthly night-time eyeshine counts aerial surveys, capturing animals, and locating and following the fate of nests. There was a strong positive correlation between water temperature and the number of alligators observed during eyeshine …

Life History And Reproductive Ecology Of Sistrurus Miliarius Barbouri : The Dusky Pygmy Rattlesnake In Long Pine Key, Everglades National Park, Teresa C. Defrancesco

FIU Electronic Theses and Dissertations

The life history and reproductive ecology of the pygmy rattlesnake, Sistrurus miliarius barbouri was studied from January, 1984 to June, 1987 at Long Pine Key, Everglades national Park. This sample exhibits no sexual dimorphism except for relative to hail lengths; mean adult size was about 47 cms. Females do however comprise the majority of the snakes over 50 cms. S.m. barbouri show no habitat preference between the four habitat types. They are active year-round theater clearly second half of the year snakes. The species activity peak is in October which marks the end of the wet season and the climax …