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Full-Text Articles in Comparative and Evolutionary Physiology

The Beat Behind The Bark: Investigating The Effects Of Music Tempo On Canine Physiological And Psychological States, Marley Lanier May 2026

The Beat Behind The Bark: Investigating The Effects Of Music Tempo On Canine Physiological And Psychological States, Marley Lanier

Poster Presentations

Music is a universal component of human culture that has been demonstrated influencing emotional, cognitive, and physiological responses, specifically heart rate and hormonal responses (Mehr et al., 2019; Trappe, 2012). Recently, this research has expended to explore how music may affect non-human animals, particularly dogs, due to their roles as therapy animals, service animals, and human companions (Lindig et al., 2020; Gee et al., 2021). Being able to understand how music influences canine stress and relaxation hold important applications in environments such as shelters, veterinary clinics, and at home. One important feature of music is tempo, or beats per minute …


Systematics Of Disk-Winged Bats (Thyroptera), Courtney L. Klumpp Jan 2026

Systematics Of Disk-Winged Bats (Thyroptera), Courtney L. Klumpp

Capstone Showcase

This thesis investigates the evolutionary relationships among disk-winged bats in the genus Thyroptera, a small group of Neotropical bats known for the adhesive suction disks on their wings and feet that allow them to roost inside tightly rolled leaves. The distinctive morphology and behavior of these bats have not been extensively documented, and their phylogenetic relationships remain only partially resolved. The goal of this research is to better understand how these species are related to one another and to determine whether the five recognized species of Thyroptera form a single monophyletic group. To address this question, morphological and genetic …


Study Of The Brain Anatomy Of Three Extinct Marsupials: Thylacinus Cynocephalus, Thylacoleo Carnifex, And Silvabestius Johnnilandi, Francisco Garcia Dec 2024

Study Of The Brain Anatomy Of Three Extinct Marsupials: Thylacinus Cynocephalus, Thylacoleo Carnifex, And Silvabestius Johnnilandi, Francisco Garcia

Honors Program Theses and Research Projects

Marsupials are pouched mammals that today are mainly found in Australasia and South America. Marsupials have proven to be quite intriguing to evolutionary biologists who note how some marsupials resemble placentals in anatomy due to convergent evolution, with both marsupials and placentals filling similar niches in their respective environments. As of today, studies interested in marsupial brain evolution have published descriptions of cranial endocasts for several species of marsupials, with the number of descriptions seeing a massive boost over the last 20 years with the arrival of CT imaging technology. However, no comprehensive study of brain evolution in marsupials has …


Comparing Ionoregulation And Modes Of Nitrogen Excretion Across The Life Cycle Of Parasitic And Non-Parasitic Lamprey Species, Shannon Davidson Jan 2024

Comparing Ionoregulation And Modes Of Nitrogen Excretion Across The Life Cycle Of Parasitic And Non-Parasitic Lamprey Species, Shannon Davidson

Theses and Dissertations (Comprehensive)

Abstract

Ionoregulation and nitrogenous waste (N-waste) metabolism in fishes has been extensively documented in teleosts and elasmobranchs, but less so in lampreys (Petromizontiformes). All lamprey species undergo metamorphosis which drastically changes their physiology and modes of feeding. However, differences in ionoregulatory mechanisms due to anadromous versus non anadromous life history strategies emerge following metamorphosis in different lamprey species. Furthermore, some species, such as anadromous juvenile sea lamprey (Petromyzon marinus), are parasitic and migrate to seawater (SW) to ingest blood protein from host fishes, while juveniles of freshwater (FW), non-parasitic species, such as the American brook lamprey …


Hypothalamic Manipulation Of The Anuran Hpg Axis: Alternative Hormones And A Non-Invasive Administration Route For Amphibian Assisted Reproductive Technologies (Art), Erin Michelle Saylor Dec 2023

Hypothalamic Manipulation Of The Anuran Hpg Axis: Alternative Hormones And A Non-Invasive Administration Route For Amphibian Assisted Reproductive Technologies (Art), Erin Michelle Saylor

Theses and Dissertations

Amidst the amphibian extinction crisis, in situ and ex situ amphibian species conservation initiatives utilize assisted reproductive technologies for optimal genetic management of captive and wild populations. Development of effective, simple, low-cost methods for obtaining gametes for artificial fertilization, sperm biobanking, or natural breeding alleviates obstacles for institutions or programs to apply reproductive technologies. Objectives herein include investigating the efficacy of alternative hormones for inducing spermiation, an alternative hormone administration route for inducing ovulation, exploring the physiological effects of hormone therapy, and utilizing sperm from deceased animals for biobanking.


Use Of Hematological Markers To Assess Physiological Condition And Health Status In Free-Ranging Sand Tiger Sharks (Carcharias Taurus), Chestina N. Craig Jan 2023

Use Of Hematological Markers To Assess Physiological Condition And Health Status In Free-Ranging Sand Tiger Sharks (Carcharias Taurus), Chestina N. Craig

College of Graduate Studies: Theses & Dissertations

The contents of blood can provide information about the physiological condition and health of vertebrates. This study seeks to better understand the stress physiology and blood bacteria presence of the sand tiger shark (Carcharias taurus), as sharks are known to have unique physiology and immune systems. In this study the blood metabolites glucose, lactate, and ketones (3-hydroxybuteric acid and acetoacetate), were used to understand how biotic and abiotic factors affect the acute stress response to capture and handling. Metabolite concentrations from blood plasma were analyzed using colorimetric assays. Glucose and ketones showed no significant responses to capture and …


Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters Jan 2022

Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters

Animal Sentience

Evidence for sentience in animals distantly related to humans is often sought in observations of behavioral and neural responses to noxious stimuli that would be painful in humans. Most proposed criteria for painful sentience in “lower” animals such as decapod crustaceans have no necessary links to the affective (“suffering”) component of pain. The best evidence for painful affect in animals is learned aversion to stimuli associated with noxious experience, and conditioned preference for contexts associated with relief from aversive consequences of noxious experience, as expressed in voluntary behavior. Such evidence is currently lacking for any invertebrate except octopus.


Comparing Interrelated Stress Measures To Differentiate Acute And Chronic Stress In Urban Freshwater Turtles, Katherine Caldwell Jan 2021

Comparing Interrelated Stress Measures To Differentiate Acute And Chronic Stress In Urban Freshwater Turtles, Katherine Caldwell

Honors Program Theses

As urban areas grow in size and number, there are increasing impacts on the wildlife. While some species adapt, others cannot thrive in these conditions. Stress is the biological response to a stimulus that threatens homeostasis, which can be used to understand the condition of an individual. While acute stress is beneficial for survival, chronic stress can lead to deleterious impacts. A majority of turtles can be classified as declining in number or endangered, yet there is little understanding of their physiological stress response. This study examined how various stress measures—including corticosterone (CORT) in plasma, nails and leeches, metabolic measures, …


The Evolution Of Dragons, Laura J. Mayfield Jan 2020

The Evolution Of Dragons, Laura J. Mayfield

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Dragons have been depicted in human art as early as 4500 BCE. For centuries, these fantasy creatures have inspired countless folk and fantasy tales, as well as appearing in the art of different cultures around the world. Now there are thousands of different depictions of these huge, flying, fire-breathing lizards, but are any of them possible? In this study, I reference peer-reviewed scientific articles, phylogenetic analysis, and paleoart studies to create biologically-sound dragons. Basing the dragon lineage on a real branch of webbed-winged scansoriopterygids—an extinct family of climbing and gliding maniraptoran dinosaurs—I explored the possible wing-structure, fire-breathing abilities, and effects …


Eastern Collared Lizard (Crotaphytus Collaris) Population Declines In Ozark Landscapes: An Assessment Of Environmental Constraints., Casey L. Brewster Dec 2019

Eastern Collared Lizard (Crotaphytus Collaris) Population Declines In Ozark Landscapes: An Assessment Of Environmental Constraints., Casey L. Brewster

Graduate Theses and Dissertations

The Eastern Collared Lizard (Crotaphytus collaris) has experienced extensive population declines over the past half century in the Ozark Mountains. Previous research suggests that glade habitat degradation through woody vegetation encroachment is an important factor resulting in population declines. In this dissertation I used information on time-energy budgets to investigate the link between habitat degradation and shifts in life history traits likely resulting in population declines of Eastern Collared Lizards (Crotaphytus collaris) in the Ozarks. In chapter one, I addressed the influence of dense woody vegetation encroachment on age-specific growth, body size, body condition and reproduction of C. collaris in …


Impact Of Intrinsic Physiological Factors In The Population Recovery Of Myotis Lucifugus (Little Brown Myotis) From White-Nose Syndrome, Caroline Burke, Caitlin Looney, Alissah Sillah, Christopher Richardson Mar 2019

Impact Of Intrinsic Physiological Factors In The Population Recovery Of Myotis Lucifugus (Little Brown Myotis) From White-Nose Syndrome, Caroline Burke, Caitlin Looney, Alissah Sillah, Christopher Richardson

Lesley University Community of Scholars Day

White-nose Syndrome (WNS) has decimated populations of hibernating bats in the US. In particular, Myotis lucifugus (little brown myotis) has been one of the most affected. We investigated the energetic cost of innate immune response and Pseudogymnoascus destructans (Pd) fungal activity on post-hibernating little brown myotis and the link with the recovery of local populations in New England from WNS. We captured bats at one of each of 4 colonies in Eastern Massachusetts and Southern New Hampshire, consecutively, every 14 days to minimize disturbance to the colony. Blood samples were collected from each bat. Respirometry trials were performed on each …


Alternative Nad(P)H Dehydrogenase And Alternative Oxidase: Proposed Physiological Roles In Animals, Allison Mcdonald, Dmytro V. Gospodaryov Mar 2019

Alternative Nad(P)H Dehydrogenase And Alternative Oxidase: Proposed Physiological Roles In Animals, Allison Mcdonald, Dmytro V. Gospodaryov

Biology Faculty Publications

The electron transport systems in mitochondria of many organisms contain alternative respiratory enzymes distinct from those of the canonical respiratory system depicted in textbooks. Two of these enzymes, the alternative NADH dehydrogenase and the alternative oxidase, were of interest to a limited circle of researchers until they were envisioned as gene therapy tools for mitochondrial disease treatment. Recently, these enzymes were discovered in several animals. Here, we analyse the functioning of alternative NADH dehydrogenases and oxidases in different organisms. We propose that both enzymes ensure bioenergetic and metabolic flexibility during environmental transitions or other conditions which may compromise the operation …


Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin Jan 2019

Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Habitat creation is an important tool for conservation to counteract habitat loss and degradation. Vernal pools are susceptible to destruction due to limited detection, protection, and regulation. These wetlands provide fishless breeding habitat for many amphibian species including spotted salamanders (Ambystoma maculatum) in eastern North America. Determining whether created vernal pool habitat is successful is often determined by demographic data of colonizing populations. I suggest that hormone levels, population genetics, and disease prevalence can improve our understanding of population health in created habitat. The goal of this dissertation was to assess the health of spotted salamander larvae in …


Gill Structure & Function In Parasitic And Non-Parasitic Lampreys: The Effects Of Metamorphosis And Freshwater-Seawater Transfer, Julia Sunga Jan 2018

Gill Structure & Function In Parasitic And Non-Parasitic Lampreys: The Effects Of Metamorphosis And Freshwater-Seawater Transfer, Julia Sunga

Theses and Dissertations (Comprehensive)

Lamprey (Petromyzontiformes) are a phylogenetically ancient group of jawless fishes that begin their lives as filter-feeding larvae (ammocoetes) before undergoing a complex metamorphosis into juvenile lamprey that involves major changes to their internal and external body plan. Some parasitic species, such as the sea lamprey (Petromyzon marinus), migrate to sea following metamorphosis, where they use their oral discs and rasping tongue to attach to and ingest vast quantities of blood from fishes. Thus, sea lamprey have to counter the simultaneous challenges of hyposmoregulation in sea water and the generation of large quantities of ammonia due to the …


Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker Mar 2017

Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Species endemic to oceanic islands offer unique insights into the mechanisms underlying evolution and have served as model systems for decades. Often these species show phenotypic variation that is correlated with the ecosystems in which they occur and such correlations may be a product of genetic drift, natural selection, and/or environmental factors. We explore the morphologic and genetic variation within Ardops nichollsi, a species of phyllostomid bat endemic to the Lesser Antillean islands. Ardops nichollsi is an ideal taxon to investigate the tempo of evolution in Chiroptera, as it: is a recently derived genus in the family Phyllostomidae; contains …


Gait Changes In A Line Of Mice Artificially Selected For Longer Limbs, Leah M. Sparrow, Emily Pellattt, Sabrina S. Yu, David A. Raichlen, Herman Pontzer, Campbell Rolian Feb 2017

Gait Changes In A Line Of Mice Artificially Selected For Longer Limbs, Leah M. Sparrow, Emily Pellattt, Sabrina S. Yu, David A. Raichlen, Herman Pontzer, Campbell Rolian

Publications and Research

In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged …


Histology Of Rathke’S Glands In The Razor-Backed Musk Turtle, Sternotherus Carinatus (Chelonia: Kinosternidae), With Comments On Lamellar Bodies, S. E. Trauth Jan 2017

Histology Of Rathke’S Glands In The Razor-Backed Musk Turtle, Sternotherus Carinatus (Chelonia: Kinosternidae), With Comments On Lamellar Bodies, S. E. Trauth

Journal of the Arkansas Academy of Science

I examined the histology and ultrastructure of Rathke’s glands in two adult male razor-backed musk turtles (Sternotherus carinatus) collected in northeastern Arkansas. This species possesses two pairs of Rathke’s glands that are embedded beneath marginal bones and are named according to their anatomical location (i.e., axillary and inguinal). These integumentary glands are similar anatomically to one another. Each gland is comprised of a single, highly vascularized secretory lobule, which is surrounded by a thin tunic of asymmetrically arranged, striated muscle. Two types of large secretory vacuoles characterize most of the holocrine cells produced by a relatively thin secretory …


Validation Of The Use Of Doubly Labeled Water For Measuring Metabolic Rate In Timber Rattlesnakes (Crotalus Horridus), Caitlin Hirsh May 2016

Validation Of The Use Of Doubly Labeled Water For Measuring Metabolic Rate In Timber Rattlesnakes (Crotalus Horridus), Caitlin Hirsh

Biological Sciences Undergraduate Honors Theses

The doubly labeled water method is an isotopic technique for measuring field metabolic rate and water flux rates of free-living animals. We present a validation of the use doubly labeled water for measuring metabolic rate and water loss in Timber Rattlesnakes (Crotalus horridus). For this study seven animals of varying body size were used with masses ranging from 148 to 650 grams. Prior to dosing, blood samples were taken to establish background isotope levels for each animal. Snakes were injected with water enriched with isotopes of oxygen (18O) and hydrogen (2H, deuterium). The injected isotopes were then allowed to equilibrate …


Description Of Cranial Elements And Ontogenetic Change Within Tropidolaemus Wagleri (Serpentes: Crotalinae)., Nicolette L. Hill May 2016

Description Of Cranial Elements And Ontogenetic Change Within Tropidolaemus Wagleri (Serpentes: Crotalinae)., Nicolette L. Hill

Electronic Theses and Dissertations

Tropidolaemus wagleri is a species of Asian pitviper with a geographic range including Thailand, Vietnam, Malaysia, Singapore, Bruniei, parts of Indonesia, and the hilippines. Tropidolaemus is a member of the Crotalinae subfamily, within Viperidae. The genus Tropidolaemus includes five species, and was once included within the genus Trimeresurus. While some osteologic characteristics have been noted a comprehensive description of cranial elements has not been produced for T. wagleri. An in-depth description of the cranial skeleton of Tropidolaemus wagleri lays the foundation for future projects to compare and contrast other taxa within Crotalinae and Viperidae. The chosen reference specimen …


Elevational Variation In Body-Temperature Response To Immune Challenge In A Lizard, Francisco Javier Zamora-Camacho, Senda Reguera, Gregorio Moreno-Rueda Apr 2016

Elevational Variation In Body-Temperature Response To Immune Challenge In A Lizard, Francisco Javier Zamora-Camacho, Senda Reguera, Gregorio Moreno-Rueda

Dartmouth Scholarship

Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1) hypothermia would be …


Anthropomorphic Denial Of Fish Pain, Lynne U. Sneddon, Matthew C. Leach Jan 2016

Anthropomorphic Denial Of Fish Pain, Lynne U. Sneddon, Matthew C. Leach

Animal Sentience

Key (2016) affirms that we do not know how the fish brain processes pain but denies — because fish lack a human-like cortex — that fish can feel pain. He affirms that birds, like fish, have a singly-laminated cortex and that the structure of the bird brain is quite different from that of the human brain, yet he does not deny that birds can feel pain. In this commentary we describe how Key cites studies that substantiate mammalian pain but discounts the same kind of data as evidence of fish pain. We suggest that Key's interpretations are illogical, do not …


Salinity Preference Of Alaskan Threespine Stickleback: Test For Divergence In Halotaxis Between Ancestral And Landlocked Populations, David Fryxell, Eric T. Schultz Jan 2012

Salinity Preference Of Alaskan Threespine Stickleback: Test For Divergence In Halotaxis Between Ancestral And Landlocked Populations, David Fryxell, Eric T. Schultz

EEB Articles

Glacial retreat during the Pleistocene caused landlocking of anadromous Alaskan threespine stickleback, Gasterosteus aculeatus, furnishing a natural ‘experiment’ in osmoregulatory divergence. The objective of this study was to assess the effects of individual acclimation and population divergence on salinity preference. Full-sibling families of marine, anadromous, and freshwater-landlocked populations of stickleback were reared in common environments until 3 weeks post-hatch, then were split and acclimated to low or high salinity. At 6 to 8 weeks of age the six experimental groups were tested for salinity preference in a tank that offers fish a choice of compartments with different salinities arranged …


Foraging And Roosting Behaviors Of Rafinesque's Big-Eared Bat (Corynorhinus Rafinesquii) At The Northern Edge Of The Species Range, Joseph S. Johnson Jan 2012

Foraging And Roosting Behaviors Of Rafinesque's Big-Eared Bat (Corynorhinus Rafinesquii) At The Northern Edge Of The Species Range, Joseph S. Johnson

Theses and Dissertations--Animal and Food Sciences

Bat populations in the eastern United States are currently declining at unprecedented rates as a result of habitat loss, commercial wind energy development, and white-nose syndrome. Effective conservation of these declining populations requires knowledge of several aspects of summer and winter ecology, including daytime habitat use (day-roost selection and social behaviors), nocturnal habitat use (foraging habitat selection, prey selection, and prey abundance), and winter hibernation (torpor) patterns. This dissertation addresses these questions for Rafinesque’s big-eared bat (Corynorhinus rafinesquii), a species of conservation concern in the southeastern United States. Kentucky represents the northern edge of the range of Rafinesque’s …


Interspecific Variation In Palatability Suggests Cospecialization Of Antipredator Defenses In Sea Hares, Kimberly K. Takagi, Nadia N. Ono, William G. Wright Jan 2010

Interspecific Variation In Palatability Suggests Cospecialization Of Antipredator Defenses In Sea Hares, Kimberly K. Takagi, Nadia N. Ono, William G. Wright

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Prey species often deploy different kinds of antipredator defenses, which can interact with each other in ways that are not yet completely understood. Much research into these interactions has utilized gastropod mollusks, usually focusing (in part) on the protective utility of the gastropod shell. This makes the evolutionary reduction of the shell in the opisthobranch gastropods (marine slugs) particularly interesting. This loss of protective function of the shell is associated with the evolution of alternative defenses. Particularly well studied are chemical defenses, especially those using secondary metabolites derived from food resources. As a first step toward understanding interspecific variation in …


Hatching Asynchrony, Survival, And The Fitness Of Alternative Adult Morphs In Ambystoma Talpoideum, Travis J. Ryan Jan 2004

Hatching Asynchrony, Survival, And The Fitness Of Alternative Adult Morphs In Ambystoma Talpoideum, Travis J. Ryan

Scholarship and Professional Work - LAS

The mole salamander, Ambystoma talpoideum, exhibits both aquatic (gilled) and terrestrial (metamorphosed) adult morphologies. Previous studies have shown the existence of body-size advantages associated with the terrestrial morph in A. talpoideum and other polymorphic salamanders (e.g., A. tigrinum). However, aquatic adult A. talpoideum mature at a younger age and often breed earlier than terrestrial adults. We tested the hypothesis that early maturation and reproduction in aquatic adults increase fitness (irrespective of body size). We reared larval A. talpoideum in mesocosms and varied the timing of hatching, with early-hatching larvae representing the offspring from early-breeding aquatic adults, and late-hatching larvae representing …


Thermoregulation In Swimming Mallard Ducklings (Anas Platyrhynchos), Aaron James Lynott May 2003

Thermoregulation In Swimming Mallard Ducklings (Anas Platyrhynchos), Aaron James Lynott

All-Inclusive List of Electronic Theses and Dissertations

Temperature regulation in birds has been studied for several decades. However, most studies have been limited to the thermal effects of air. This is surprising considering the abundance of waterfowl and the significant amount of time that many birds spend immersed in water. While we do know that water has a thermal conductivity that is 23 times that of air, the effect of water temperature on temperature regulation remains unknown. Though the thermal effect of water seemingly has a strong influence on the thermoregulation of birds, neonatal aquatic birds seem particularly susceptible. Many aquatic neonates, such as mallard ducklings, enter …


Morphological Variation In The Southeastern Pocket Gopher, Geomys Pinetis (Mammalia: Rodentia), Stephen L. Williams, Hugh H. Genoways Dec 1980

Morphological Variation In The Southeastern Pocket Gopher, Geomys Pinetis (Mammalia: Rodentia), Stephen L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

The nominal species of southeastern pocket gophers (Geomys pinetis, G. colonus, G. cumberlandius, and G. fontanelus), which collectively occupy a geographic range on the Atlantic and Gulf coastal plain of Alabama, Georgia, and Florida, were examined for morphological variation. Univariate and multivariate analyses were used to determine age, sexual, individual, and geographic variation in G. pinetis. Significant differences were found among different age classes and between sexes. Males displayed higher individual variation than females and external measurements were more variable than cranial measurements. Of the four named species in the pinetis-species group (colonus …


Critical Flicker Frequency In A Harp Seal, Pagophilus Groenlandicus (Erxleben, 1777), Charles D. Bernholz Jan 1973

Critical Flicker Frequency In A Harp Seal, Pagophilus Groenlandicus (Erxleben, 1777), Charles D. Bernholz

University of Nebraska-Lincoln Libraries: Faculty Publications

Critical flicker frequency (CFF) in a free-swimming harp seal (Pagophilus groenlandicus) was investigated using behavioral techniques. The resulting CFF versus intensity contour indicates a definite rod-cone break, confirming a duplex photoreceptor population whose presence had not been observed in previous morphological reports.