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(1 - 8 of 8)
- Title
- AN INVESTIGATION INTO THE NATURE OF ANAL FIN GLANDS IN FISHES OF THE FAMILY BLENNIIDAE.
- Creator
- Porter, Marianne C., Florida Atlantic University
- Abstract/Description
-
Sexually active males of the family Blenniidae develop distinctive glandular swellings of the anal fins. These glands can be divided into four groups on the basis of their shape and whether they appear on the anal fin spines or rays or both. Examples of each group, when studied microscopically, show the same histological pattern. This pattern includes three layers of tissue, the outermost of which contains characteristic barrel-shaped groupings of cells called "microglands". These anal fin...
Show moreSexually active males of the family Blenniidae develop distinctive glandular swellings of the anal fins. These glands can be divided into four groups on the basis of their shape and whether they appear on the anal fin spines or rays or both. Examples of each group, when studied microscopically, show the same histological pattern. This pattern includes three layers of tissue, the outermost of which contains characteristic barrel-shaped groupings of cells called "microglands". These anal fin glands are compared histologically to similar structures on the dorsal fins of some blenniids and the anal fins of certain clinids. The microscopic structure of the anal fin glands is distinctive and characteristic.
Show less - Date Issued
- 1979
- PURL
- http://purl.flvc.org/fcla/dt/13962
- Subject Headings
- Blenniidae, Fins (Anatomy)
- Format
- Document (PDF)
- Title
- 2D AND 3D SHAPE VARIATION AMONG ELASMOBRANCH OLFACTORY ROSETTES.
- Creator
- Clark, Aubrey E., Porter, Marianne E., Meredith, Tricia L., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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The functional impacts of olfactory rosette variation in elasmobranchs is unresolved. Our goal was to quantify rosette morphology and shape from 14 species using dissections, phylogenetic comparisons, and microCT imaging. We hypothesized that lamellar count and rosette shape (fineness ratio) would not scale with animal size, but internal rosette size variables must scale positively. We found that fineness ratio and lamellar counts varied significantly among species, and were positively...
Show moreThe functional impacts of olfactory rosette variation in elasmobranchs is unresolved. Our goal was to quantify rosette morphology and shape from 14 species using dissections, phylogenetic comparisons, and microCT imaging. We hypothesized that lamellar count and rosette shape (fineness ratio) would not scale with animal size, but internal rosette size variables must scale positively. We found that fineness ratio and lamellar counts varied significantly among species, and were positively correlated. The first two principal components of the pPCA explained 82% of the variation, with fineness ratio and lamellar count contributing the most. There were no significant differences between rosette structure or volume when comparing dissected values to in situ values obtained using diceCT. Based on our results, we hypothesize that variations in rosette shape and morphology will impact hydrodynamics and optimize odorant detection, and these data can be used to create 3D models for future hydrodynamic studies.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013591
- Subject Headings
- Elasmobranchs, Olfactory sensors, Morphology
- Format
- Document (PDF)
- Title
- The Functional Morphology of Shark Control Surfaces: A Comparative Analysis.
- Creator
- Hoffmann, Sarah Louise, Porter, Marianne E., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Sharks are an objectively diverse group of animals; ranging in maximum size from 2,000cm (whale shark) to 17cm (dwarf lantern shark); occupying habitats that are periodically terrestrial (epaulette shark) to the deepest parts of the ocean (frilled shark); relying on a diversity of diets from plankton to marine mammals; with vast amounts of morphology diversity such as the laterally expanded heads of hammerhead species, the elongate caudal fins of thresher species, and the tooth embedded...
Show moreSharks are an objectively diverse group of animals; ranging in maximum size from 2,000cm (whale shark) to 17cm (dwarf lantern shark); occupying habitats that are periodically terrestrial (epaulette shark) to the deepest parts of the ocean (frilled shark); relying on a diversity of diets from plankton to marine mammals; with vast amounts of morphology diversity such as the laterally expanded heads of hammerhead species, the elongate caudal fins of thresher species, and the tooth embedded rostrum of saw shark species representing some of the anatomical extremes. Yet despite these obvious differences in morphology, physiology, and ecology, the challenges associated with studying hard to access, large bodied, pelagic animals have limited our comparative understanding of form and function as it relates to swimming within this group. The majority of shark swimming studies examine species that succeed in captivity, which are usually benthic associated sharks that spend time resting on the substrate. These studies have also been limited by the use of flumes, in which the unidirectional flow and small working area precludes the analysis of larger animals, volitional swimming, and maneuvering. The few existing volitional kinematics studies on sharks quantify two-dimensional kinematics which are unable to capture movements not observable in the plane of reference. With this study, we quantified the volitional swimming kinematics of sharks in relation to morphological, physiological, and ecological variation among species. We developed a technique to analyze three-dimensional (3D) kinematics in a semi-natural, large volume environment, which, to our knowledge, provides the first3D analysis of volitional maneuvering in sharks. We demonstrated that Pacific spiny dogfish and bonnethead sharks rotate the pectoral fins substantially during yaw (horizontal) maneuvering and is correlated with turning performance. We proposed that ecomorphological differences correlate with the varied maneuvering strategies we observed between the two species. We also found that there is some mechanical constraint on shark pectoral fin shape that is explained by phylogenetic relationships but describe a continuum of morphological variables within that range. We propose standardized terminology and methodology for the future assessment of shark pectoral fin morphology and function. As with previous studies, the ease of access to species was a challenge in this study and future studies should continue to assess the functional ecomorphology of shark pectoral fins among species.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013217
- Subject Headings
- Sharks, Morphology (Animals), Kinematics
- Format
- Document (PDF)
- Title
- TO BUILD AN INVASIVE PREDATOR: INVESTIGATING THE MECHANICAL ROLE OF LIONFISH SPINES ON DEFENSE.
- Creator
- Galloway, Katherine Ann, Porter, Marianne E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The red lionfish, Pterois volitans, has arguably become the most successful marine invasive species to date. Yet, despite the invasion success of P. volitans, little is known about the morphology, physiology, and ecology of this species in their native and invaded habitats. The majority of recent studies have focused on the migration of P. volitans into new regions, digestion, and bacterial infections. Knowledge is lacking on the body plan of the invasive lionfish, specifically the numerous...
Show moreThe red lionfish, Pterois volitans, has arguably become the most successful marine invasive species to date. Yet, despite the invasion success of P. volitans, little is known about the morphology, physiology, and ecology of this species in their native and invaded habitats. The majority of recent studies have focused on the migration of P. volitans into new regions, digestion, and bacterial infections. Knowledge is lacking on the body plan of the invasive lionfish, specifically the numerous venomous spines that are protruding outward, making the body less streamlined. In this study we quantified the mechanical properties (bending and puncture) of the venomous spines of P. volitans, and related these properties to the cross-sectional morphology. We also documented variation in the cross-sectional morphology of spines from other lionfish species in their native regions. Lastly, we documented the dorsal spine joint morphology of the first three dorsal spines and the in situ range of motion as tissues were removed. We found that the long, numerous dorsal spines absorb more energy but are less stiff than the pelvic and anal spines. In addition, we found that the anal and pelvic spines are more effective at puncturing buccal skin from sharks and grouper. We found that the removal of connective tissue significantly changes lateral movement (abduction) for the first three dorsal spines. The removal of the fin sheath significantly alters forward movement (extension) for the first two dorsal spines. From morphology, mechanical property, and range of motion data for P. volitans, we propose that the numerous long dorsal spines are primarily used for intimidation, and are not as effective defense structures as the pelvic and anal spines. Having a substantial amount of intimidating, venomous spines may allow for the lionfish to conserve energy for other highly metabolically costly activities other than warding off predators, such as digestion and reproduction. Future studies could focus on the amount of venom in each spine, how long it takes for the venom to be made and replaced, how the venomous spines affect hydrodynamic flow, and in vivo range of motion during swimming and striking.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013512
- Subject Headings
- Red lionfish, Pterois volitans, Spines (Zoology), Mechanical properties of biological structures, Biomechanics
- Format
- Document (PDF)
- Title
- NOT SO STRAIGHT FORWARD: SWIMMING, MANEUVERING, AND FEEDING KINEMATICS OF THE SCALLOPED HAMMERHEAD (SPHYRNA LEWINI).
- Creator
- Heerdegen, Ivan, Porter, Marianne E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Many studies on shark swimming have examined kinematic variables along straight tracks or under controlled flow speeds in flumes, but there is less known about unsteady swimming during maneuvering or feeding. Sharks may adjust their speed, undulatory kinematics, or body curvature to accommodate different actions. This study quantified variations in kinematics during straight swimming, maneuvering, and feeding in scalloped hammerhead sharks (Sphyrna lewini). I obtained video of three juvenile...
Show moreMany studies on shark swimming have examined kinematic variables along straight tracks or under controlled flow speeds in flumes, but there is less known about unsteady swimming during maneuvering or feeding. Sharks may adjust their speed, undulatory kinematics, or body curvature to accommodate different actions. This study quantified variations in kinematics during straight swimming, maneuvering, and feeding in scalloped hammerhead sharks (Sphyrna lewini). I obtained video of three juvenile scalloped hammerheads, developed an ethogram assessing three behavioral categories, and tracked points along the body’s midline. I found that velocity was lower during feeding compared to maneuvering and straight swimming, while body curvature increased during feeding turns but decreased with increasing velocity. These data will provide insight into kinematic variations in hammerhead sharks across ontogeny and among behaviors, ultimately expanding on the relationship between form and function. This also provides context for varying behaviors and trends within the movement ecology paradigm.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014079
- Subject Headings
- Kinematics, Hammerhead sharks
- Format
- Document (PDF)
- Title
- THE ANISOTROPIC MECHANICAL PROPERTIES AND MORPHOLOGY OF ELASMOBRANCH SKIN.
- Creator
- Hagood, Madeleine Elizabeth, Porter, Marianne E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The goal of these studies was to quantify mechanical properties of elasmobranch (sharks and batoids) skin to understand the functional relationships between mechanics and morphology, and how these correspond to differences in swimming and ecology. I relate mechanical behaviors with morphological structures to elucidate the underlying contributions of the skin toward elasmobranch skin mechanics. I mechanically tested skin in uniaxial tension to failure to assess the tensile strain at maximum...
Show moreThe goal of these studies was to quantify mechanical properties of elasmobranch (sharks and batoids) skin to understand the functional relationships between mechanics and morphology, and how these correspond to differences in swimming and ecology. I relate mechanical behaviors with morphological structures to elucidate the underlying contributions of the skin toward elasmobranch skin mechanics. I mechanically tested skin in uniaxial tension to failure to assess the tensile strain at maximum load (extensibility), ultimate tensile strength, Young’s Modulus of elasticity (stiffness), and toughness among diverse groups of elasmobranchs. Across three chapters, I compare mechanical behaviors of the skin among species of sharks and batoids (separately) among body regions, and between sexes and axes of stress (longitudinal and hoop). Among 20 shark species, I quantified mechanical properties among ecomorphotypes and ontogenetically (across three maturity stages) and found that mechanical behaviors increase ontogenetically and are governed by two different underlying trends (maturity and ecomorphology). I found that shark skin oriented in the hoop direction was stronger and stiffer compared to skin oriented longitudinally, as hoop-oriented skin maintains internal volume and hydrostatic pressure by resisting deformation. Shark skin oriented longitudinally was more extensible, allowing for increased stretchability anteroposterior as a shark’s body undulates along the longitudinal axis. Dermal denticles (placoid scales), tooth-like structures of enameloid and dentine, are rooted in the stratum compactum layer of the dermis, embedded in a collagen fiber network.
Show less - Date Issued
- 2024
- PURL
- http://purl.flvc.org/fau/fd/FA00014525
- Subject Headings
- Cartilaginous fishes, Fish skin, Morphology, Anisotropy
- Format
- Document (PDF)
- Title
- A Comparative Study on the Tensile Properties of Shark Skin.
- Creator
- Creager, Shelby, Porter, Marianne C., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Our goal was to assess regional differences in denticle density and skin tensile properties in four coastal species of shark. We hypothesized that the denticle density, tensile strength (MPa), stiffness (MPa), and toughness of skin (MJ·m^-3) would vary regionally along the body of an individual and among species. An hourglass-shaped punch was used to extract the skin samples at 10 anatomical landmarks and denticle density was quantified. Denticle density varied significantly among both...
Show moreOur goal was to assess regional differences in denticle density and skin tensile properties in four coastal species of shark. We hypothesized that the denticle density, tensile strength (MPa), stiffness (MPa), and toughness of skin (MJ·m^-3) would vary regionally along the body of an individual and among species. An hourglass-shaped punch was used to extract the skin samples at 10 anatomical landmarks and denticle density was quantified. Denticle density varied significantly among both regions and species, and showed a significant species by region interaction. Skin samples were tested in tension at a strain rate of 2 mm-s until failure. We found significant species and region effects for all tensile and denticle density properties. Also, denticle density increases with skin stiffness but decreases with toughness. Shark skin toughness is similar to that of mammalian tendons. These data show shark skin functions as an exotendon, able to conserve energy during swimming.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004761, http://purl.flvc.org/fau/fd/FA00004761
- Subject Headings
- Sharks--Anatomy., Sharks--Locomotion., Surfaces (Physics), Biophysics.
- Format
- Document (PDF)
- Title
- THE FORM AND FUNCTION OF VERTEBRAL TRABECULAR BONE IN FULLY AQUATIC MAMMALS.
- Creator
- Ingle, Danielle Nicole, Porter, Marianne, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Among vertebrates, whole-body movement is centered around the vertebral column. The bony vertebral column primarily consists of trabecular (spongy) bone that adapts in vivo to support mechanical demands respective to region, ontogeny, ecology, and locomotion. Previous work has extensively investigated the formfunction relationships of vertebral trabecular bone in terrestrial mammals, who use limb contact with a substrate as the primary support against gravity. However, we lack data from...
Show moreAmong vertebrates, whole-body movement is centered around the vertebral column. The bony vertebral column primarily consists of trabecular (spongy) bone that adapts in vivo to support mechanical demands respective to region, ontogeny, ecology, and locomotion. Previous work has extensively investigated the formfunction relationships of vertebral trabecular bone in terrestrial mammals, who use limb contact with a substrate as the primary support against gravity. However, we lack data from obligate swimming mammals whose locomotor ecology diverged from their terrestrial counterparts in two major ways: (1) body mass is supported by water’s uplifting buoyant forces and (2) swimmers power movement through dorsoventral loading of the axial body. This study examined vertebral trabecular bone mechanical properties and micoarchitecture from fully aquatic mammals, specifically sirenians (i.e. manatees) and cetaceans (i.e. dolphins and whales). We compression tested bone from several regions of the vertebral column among developmental stages in Florida manatees (Trichechus manatus latirostris) and among 10 cetacean species (Families Delphinidae and Kogiidae) with various swimming modes and diving behaviors. In addition, we microCT scanned a subset of cetacean vertebrae before subjecting them to mechanical tests. We demonstrated that in precocial manatee calves, vertebrae were the strongest and toughest in the posterior vertebral column, which may support rostrocaudal force propagation and increasing bending amplitudes towards the tail tip during undulatory swimming. Among cetaceans, we showed that greatest strength, stiffness, toughness, bone volume fraction, and degree of anisotropy were in rigidtorso shallow-divers, while properties had the smallest values in flexible-torso deep-divers. We propose that animals swimming in shallower waters actively swim more than species that conduct habitual glides during deep descents in the water column, and place comparatively greater loads on their vertebral columns. We found that cetacean bone volume fraction was the best predictor for mechanical properties. Due to the shared non-weight bearing conditions of water and microgravity, we present these data as a contribution to the body of work investigating bone adaptations in mammals that live in weightless conditions throughout life and evolutionary history.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013529
- Subject Headings
- Cancellous Bone, Vertebrae, Aquatic mammals, Sirenia, Cetaceans, Bones--Mechanical properties
- Format
- Document (PDF)
