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- Title
- PHYSIOLOGICAL ADAPTATIONS OF DIAMOND KILLIFISH (ADINIA XENICA) TO SURVIVE TEMPERATURE EXTREMES.
- Author
- McAcy, Bethany Nicole, Bennett, Wayne A., Daly-Engel, Toby S., Fox, Theodore C., University of West Florida
- Abstract/Description
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Diamond killifish, Adinia xenica, is a species of shallow saltmarsh fish subject to rapid temperature increases over short periods of time as well as high and low temperature extremes; however, little is known about this organism's thermal ecology. Chronic thermal maxima and minima were measured in addition to critical thermal maxima and minima (CTmaxima/minima) at four acclimation temperatures in order to construct a thermal polygon and quantify the thermal niche of diamond killifish. Fish...
Show moreDiamond killifish, Adinia xenica, is a species of shallow saltmarsh fish subject to rapid temperature increases over short periods of time as well as high and low temperature extremes; however, little is known about this organism's thermal ecology. Chronic thermal maxima and minima were measured in addition to critical thermal maxima and minima (CTmaxima/minima) at four acclimation temperatures in order to construct a thermal polygon and quantify the thermal niche of diamond killifish. Fish acclimated to temperatures of 10.6, 16.7, 26.1, and 35.2oC demonstrated CTmaxima of 38.6, 38.7, 42.0, and 43.8oC, and CTminima of 0.7, 1.7, 4.6, and 9.4oC respectively, and the resulting thermal polygon had an area of 1320.7oC2. Fish acclimated to 10.6, 16.8, and 26.0 oC were plunged to increased temperatures of 16.8, 26.0, and 35.6 oC respectively, and acclimation rates were measured by recording CTmaxima values after 0, 2, 5, 10, 15, 20, and 25 days. The CTmaxima of reciprocal transfers were also recorded, and resultant data were used to construct second-order polynomial regressions to model acclimation from low to high and high to low temperature changes. This fish demonstrates acclimation patterns much like Cyprinodon dearborni, with most tolerance gained or lost within five days post-transfer.
Show less - Date Issued
- 2016
- Identifier
- WFE0000534, uwf:61225
- Format
- Document (PDF)
- Title
- SALINITY EFFECT ON UREA AND TMAO LEVELS IN BLOOD PLASMA OF ATLANTIC STINGRAY, DASYATIS SABINA.
- Author
- Ferer, Erin Jennifer, Bennett, Wayne A., Pomory, Christopher, Ryals, Phillip E., University of West Florida
- Abstract/Description
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The range of osmolyte adjustment tolerated by euryhaline species such as the Atlantic stingray has never been quantified. The purpose of my experiments was to determine how salinity affects osmolytes involved in osmoregulation of Atlantic stingray. Plasma osmolality and TMAO and urea concentrations were measured for 50 Atlantic stingrays acclimated at five salinity treatments between 5 and 60. Although Atlantic stingrays in my experiments stopped eating above 50, fish showed the typical...
Show moreThe range of osmolyte adjustment tolerated by euryhaline species such as the Atlantic stingray has never been quantified. The purpose of my experiments was to determine how salinity affects osmolytes involved in osmoregulation of Atlantic stingray. Plasma osmolality and TMAO and urea concentrations were measured for 50 Atlantic stingrays acclimated at five salinity treatments between 5 and 60. Although Atlantic stingrays in my experiments stopped eating above 50, fish showed the typical hyperosmotic pattern at salinities up to 60. Osmolality remained constant (721 mOsm) at salinities below 20 but increased more slowly than ambient salinity above 20. Urea concentrations in my study were consistent with reports for Atlantic stingray and other elasmobranchs. Euryhaline elasmobranch species seem to exhibit a greater capacity for urea retention. Concentrations of TMAO were nearly 45% lower than levels in other elasmobranchs. Although other osmolytes are shown to be important in some elasmobranchs, it is unclear what role they may play for Atlantic stingray. Steady increases in TMAO levels even after fish stopped eating, indicate that TMAO levels are likely controlled by physiology and not diet. Low TMAO values in spite of high urea and osmolality leave open the question of how Atlantic stingrays fill the osmotic deficit.
Show less - Date Issued
- 2007
- Identifier
- WFE0000099, uwf:60712
- Format
- Document (PDF)
- Title
- SPECIATION IN TWO CLOSELY RELATED SPECIES OF THE STARFISH LUIDIA.
- Author
- Molina, Maria del Pilar Cortes, Pomory, Christopher M., Chung, Hui-Min M., Bennett, Wayne A., University of West Florida
- Abstract/Description
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Recently established species Luidia lawrencei was compared to Luidia clathrata in order to determine whether their recent separation is supported by behavioral and physiological responses, as well as genetic differences. Behavior was assessed by recording choice of substrate for burial among four grain sizes (125, 250, 500 and 1000 ìm). Physiological responses were assessed by recording changes in activity level as a response to acute reduction in salinity. Genetic homology was assessed using...
Show moreRecently established species Luidia lawrencei was compared to Luidia clathrata in order to determine whether their recent separation is supported by behavioral and physiological responses, as well as genetic differences. Behavior was assessed by recording choice of substrate for burial among four grain sizes (125, 250, 500 and 1000 ìm). Physiological responses were assessed by recording changes in activity level as a response to acute reduction in salinity. Genetic homology was assessed using segments within the cytochrome oxidase I (COX-I) mitochondrial gene. Substrate preference trials suggested that Luidia clathrata has a preference towards smaller grain sizes, while no definite preference was found for Luidia lawrencei and no significant difference was found between the species. Salinity trial results indicated that Luidia lawrencei is more active at salinities 25 psu and higher, while Luidia clathrata is more active at salinities lower than 25 psu. Mitochondrial genome comparison returned over 99% homology among these species. While the sediment and salinity data indicate a difference in responses to habitat differences, the COX-I genetic result is strong evidence that does not support the recently proposed separation of these species contrary to what has been previously published.
Show less - Date Issued
- 2011
- Identifier
- WFE0000287, uwf:60897
- Format
- Document (PDF)
- Title
- SWIM PERFORMANCE VARIABILITY OF THREE SPECIES OF JUVENILE ELASMOBRANCHS AND ITS RELATIONSHIP TO PREDATOR AVOIDANCE.
- Author
- Wilborn, Rachel Elizabeth, Bennett, Wayne A., Smith, David J., Ryals, Phillip E., University of West Florida
- Abstract/Description
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Maximum swimming velocity, oxygen consumption, and plasma lactate levels are useful indicators for evaluating metabolic performance limits in fish. Metabolic costs of exertion, maximum swim velocities, and ventilation rates in juvenile blue-spotted ribbontail stingrays (Taeniura lymma), Atlantic stingrays (Dasyatis sabina), and white-spotted bamboo sharks (Chiloscyllium plagiosum) were quantified. All species showed a decrease in oxygen consumption postexertion, with Atlantic stingrays being...
Show moreMaximum swimming velocity, oxygen consumption, and plasma lactate levels are useful indicators for evaluating metabolic performance limits in fish. Metabolic costs of exertion, maximum swim velocities, and ventilation rates in juvenile blue-spotted ribbontail stingrays (Taeniura lymma), Atlantic stingrays (Dasyatis sabina), and white-spotted bamboo sharks (Chiloscyllium plagiosum) were quantified. All species showed a decrease in oxygen consumption postexertion, with Atlantic stingrays being significantly lower (Independent t-test; P=0.0425). Significantly higher values in plasma lactate were evident in bamboo sharks pre and postexertion (0.02 and 0.35 mmol l-1, respectively); however, values for Atlantic stingrays remained unchanged (0.91 and 0.64 mmol l-1). Atlantic and ribbontail stingrays obtained greater relative speeds (9.224 and 5.163 BL sec-1, respectively) than bamboo sharks (1.060 BL sec-1). In addition, preexertion ventilation rates in Atlantic and ribbontail stingrays were faster than bamboo sharks (71.18, 70.67, 46.75 breaths min-1, respectively), while only Atlantic stingray ventilation rates postexertion differed from either bamboo sharks or ribbontail stingrays (77.69, 62.69, 49.40 breaths min-1, respectively). These data suggest that all three species utilized aerobic metabolism in conjunction with behavioral adaptations as predator avoidance strategies, making minimal use of anaerobic metabolism for locomotion.
Show less - Date Issued
- 2007
- Identifier
- WFE0000083, uwf:60686
- Format
- Document (PDF)
- Title
- TAKE MY BREATH AWAY... PHYSIOLOGICAL RESPONSES OF ATLANTIC STINGRAYS, DASYATIS SABINA, TO CYCLING HYPOXIA.
- Author
- Dabruzzi, Theresa Francine, Bennett, Wayne A., Behan, Kristina J., Pomory, Christopher M., University of West Florida
- Abstract/Description
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Atlantic stingrays, Dasyatis sabina, inhabit shallow water seagrass habitats where they experience temperature and salinity fluctuations, as well as natural cycles of hypoxia. In this study I examined changes in gill morphology, critical oxygen minimum, and hemoglobin/hematocrit levels in Atlantic stingrays acclimated for 20 days at normoxia (.5.50 mg/l), or normoxia with 6 hour intervals of moderate (4.0 mg/l), or marked hypoxia (2.0 mg/l). Neither hematocrit (Range 7.3-7.6 g/dl) nor...
Show moreAtlantic stingrays, Dasyatis sabina, inhabit shallow water seagrass habitats where they experience temperature and salinity fluctuations, as well as natural cycles of hypoxia. In this study I examined changes in gill morphology, critical oxygen minimum, and hemoglobin/hematocrit levels in Atlantic stingrays acclimated for 20 days at normoxia (.5.50 mg/l), or normoxia with 6 hour intervals of moderate (4.0 mg/l), or marked hypoxia (2.0 mg/l). Neither hematocrit (Range 7.3-7.6 g/dl) nor hemoglobin (Range 24.3-26.7%) mean values differed significantly across treatments. Perhaps the existing hemoglobin is sufficient, or stingrays have switched to a more efficient isoform. Gill dimensions including number of primary filaments, primary filament length, and number of secondary lamellae show increasing trends with severity of hypoxic exposure. Mass specific gill surface areas ranged between 85 and 140 mm2/g, and showed a significant 1.7 fold increase in total surface area between the normoxic and markedly hypoxic treatment group. Fish in the normoxic group had significantly higher critical oxygen minima (0.67±0.11 mg/l) than stingrays in either hypoxic treatment (0.40±0.05, and 0.42±0.06 mg/l). Gill remodeling improves hypoxia tolerance and likely allows Atlantic stingrays to successfully exploit hypoxic habitats inaccessible to predators and competitors, as well as forage across a wider habitat range.
Show less - Date Issued
- 2013
- Identifier
- WFE0000409, uwf:61157
- Format
- Document (PDF)
- Title
- THERMAL ACCLIMATION DYNAMICS OF THE ATLANTIC STINGRAY, DASYATIS SABINA.
- Author
- McKiddy, Emily Anne, Bennett, Wayne A., Janosik, Alexis, Nash, Paul, University of West Florida
- Abstract/Description
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Thermal acclimation responses of Atlantic stingrays, Dasyatis sabina, were determined by reciprocal transfer of fish between 18 and 24°C or 24 and 30°C. The acclimation response ratio of fully acclimated fish showed that Atlantic stingrays gain or lose approximately 0.5°C of their thermal tolerance for every degree increase or decrease in acclimation temperature, respectively. Predictive models of thermal tolerance change over time (measured as Critical Thermal Maxima) suggest that stingrays...
Show moreThermal acclimation responses of Atlantic stingrays, Dasyatis sabina, were determined by reciprocal transfer of fish between 18 and 24°C or 24 and 30°C. The acclimation response ratio of fully acclimated fish showed that Atlantic stingrays gain or lose approximately 0.5°C of their thermal tolerance for every degree increase or decrease in acclimation temperature, respectively. Predictive models of thermal tolerance change over time (measured as Critical Thermal Maxima) suggest that stingrays are 75% acclimated by 9.5 days regardless of temperature transfer or direction of temperature change. The largest acclimation changes were seen during initial transfers indicating an asymmetrical tolerance pattern, whereby stingrays gained or lost approximately twice the heat tolerance at lower transfer temperatures (18.24°C) compared to the higher transfer treatments (24-30°C). This novel pattern of asymmetric heat tolerance acquisition may be a key adaptation necessary for surviving rapid and extreme water temperature changes Atlantic stingrays commonly experience in their natural environment.
Show less - Date Issued
- 2016
- Identifier
- WFE0000544, uwf:61231
- Format
- Document (PDF)
- Title
- THERMAL ECOLOGY AND ACTIVITY PATTERNS OF JUVENILE LEMON SHARKS (NEGAPRION BREVIROSTRIS) IN A SHALLOW WATER NURSERY.
- Author
- DiGirolamo, Anthony Louis, Jr., Bennett, Wayne A., Gruber, Samuel H., Pomory, Christopher, University of West Florida
- Abstract/Description
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Ten juvenile lemon sharks (Negaprion brevirostris) captured between July 2004 and April 2005 were fitted with iButton temperature loggers and acoustic telemetry transmitters to simultaneously monitor diel movements and temperature selection. Temperature loggers were also used to record daily environmental temperatures within each sharks nursery home range. Body temperature data show that juvenile lemon sharks did not attempt, and were perhaps precluded from, behaviorally maintaining a...
Show moreTen juvenile lemon sharks (Negaprion brevirostris) captured between July 2004 and April 2005 were fitted with iButton temperature loggers and acoustic telemetry transmitters to simultaneously monitor diel movements and temperature selection. Temperature loggers were also used to record daily environmental temperatures within each sharks nursery home range. Body temperature data show that juvenile lemon sharks did not attempt, and were perhaps precluded from, behaviorally maintaining a constant eccritic temperature. Rather the sharks appeared to behaviorally exploit their home range thermal heterogeneity in a way that allowed the juveniles body temperatures to approach the upper end of the temperatures available. It is possible that by maximizing thermal acclimation juvenile lemon sharks prolong activities such as feeding or digestion well into the cooler parts of the evening. Reductions in body temperature in the late evening and sunrise hours, on the other hand, may reduce post-feeding evacuation rates and increase absorption efficiency.
Show less - Date Issued
- 2008
- Identifier
- WFE0000108, uwf:60848
- Format
- Document (PDF)
- Title
- VENOM TOXICITY AND BIOENERGETICS OF THE SPINE FROM ATLANTIC STINGRAY, DASYATIS SABINA.
- Author
- Enzor, Laura Ann, Bennett, Wayne A., Pomory, Christopher M., Ryals, Phillip E., University of West Florida
- Abstract/Description
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Atlantic stingray, Dasyatis sabina, possess a venomous spine thought to be useful in defense. Anecdotal evidence as well as observations of stinging incidents in nature illustrate that these fish are reluctant to use the spine when threatened or attacked, and in cases where the spine is used, it is not an effective predator deterrent. Venomous systems have been shown to be metabolically expensive, raising the question of why stingrays invest in a system that is inadequate for defense. This...
Show moreAtlantic stingray, Dasyatis sabina, possess a venomous spine thought to be useful in defense. Anecdotal evidence as well as observations of stinging incidents in nature illustrate that these fish are reluctant to use the spine when threatened or attacked, and in cases where the spine is used, it is not an effective predator deterrent. Venomous systems have been shown to be metabolically expensive, raising the question of why stingrays invest in a system that is inadequate for defense. This study determines stingray venom toxicity (LC50) and quantifies metabolic costs associated with the venom delivery system. Acute toxicity tests determined a LC50 value of 0.018 mg protein·g fish-1 with the average protein content of 35.71 mg·mL venom-1. Respirometry determined that approximately 0.000162 kcal·g-1·h-1 are devoted to maintenance of venomous tissues and the spine. Caloric density of spines was measured using ballistic bomb calorimetry. The average number of kilo-calories per gram of spine weight was 0.238. Empirical and observational evidence from laboratory and field studies suggest that the spine may serve key roles in reproductive behavior and in establishing social hierarchies as well as defense.
Show less - Date Issued
- 2008
- Identifier
- WFE0000102, uwf:60849
- Format
- Document (PDF)