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Induced Spawning Of Captive Tripletail Lobotes Surinamensis, Nicholas Adams

Master's Theses

The Tripletail, Lobotes surinamensis, is an emerging candidate species for U.S. marine aquaculture. This work aimed to address two bottlenecks for hatchery production of the species by developing a hormonal induction protocol to obtain fertile spawns from captive brooders and a method for sex identification of candidate brooders.

Single pairs selected among a captive-held broodstock conditioned under a natural photothermal cycle were induced with one of five treatments (n = 5 or 6 replicates per treatment). Control (no hormone) and hCG (1,100 IU.kg^-1 for females, 550 IU.kg^-1 for males) pairs did not spawn. Pairs treated with GnRHa …

The Role Of Ly49 Receptors In Maintaining Healthy Murine Pregnancy, Michelle Belmont

Master's Theses

Natural Killer (NK) cells are abundant in pregnancy and contribute to the health of the fetus. Uterine NK (uNK) cells provide less cytotoxic function than their conventional NK (cNK) cell counterparts. Various combinations of Killer Immunoglobulin Receptor (KIR)- Human Leukocyte Antigen (HLA) on maternal NK and fetally derived cells, respectively, can have different effects on the health of pregnancy in humans. Murine NK cells contain Ly49 receptors, an equivalent to KIRs. Therefore, Ly49 receptor interactions with fetally-derived MHC-I molecules can be a valuable model for studying the role of NK cells in pregnancy. The process of spiral artery remodeling can …

Effects Of Omega-3 Fatty Acids And Hypoxia On Progesterone Biosynthesis And Mitochondrial Morphology In The Corpus Luteum, Brian Krum

Master's Theses

The corpus luteum is a transient steroidogenic endocrine gland that forms from the remnants of the ovulatory follicle. This gland is responsible for the synthesis and secretion of the hormone progesterone, which is critical for the establishment and maintenance of pregnancy. In a non-pregnant cow, PGF2a is released from the uterus to regress the corpus luteum. However, in the case of pregnancy, the embryo must mitigate PGF2a synthesis to prevent corpus luteum regression. If the embryonic signal is either too late or too weak, uterine PGF2a secretion may result in corpus luteum regression and termination of pregnancy. Omega-3 fatty acids …

Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt

Master's Theses

Marine shellfish play a vital role in intertidal ecosystems and coastal communities, but many of these fisheries are small-scale and lack the necessary monitoring to ensure long-term sustainability. Effective management often requires information on key demographic parameters, such as population status, reproduction and growth. Pismo clams (Tivela stultorum) are a culturally important and iconic species in California, which supported a thriving commercial and recreational fishery throughout much of the 1900’s. However, Pismo clam populations have declined statewide in recent decades and are attributed to human harvest and predation by California sea otters (Enhydra lutris); However, no …

Reproductive Performance, Foraging Effort, And Diet Of An Apex Predator, The Common Murre, At One Of The Largest Nesting Colonies In The California Current System, Stephanie Rianne Schneider

Master's Theses

Common Murre (Uria aalge) are the most abundant avian apex predator nesting in the California Current System (CCS) and nesting is the most energetically demanding phase of their lifecycle. The preyscape within flight distance of their nesting colony determines whether murres produce young, how hard they must work to do so, and what prey types are available to them. This study characterized the reproductive performance, foraging effort, and prey composition of murres nesting at a previously unstudied and large nesting colony in the CCS, Castle Rock National Wildlife Refuge, over an 11-year period (2007 - 2017) intended to capture a …

Life-History Characteristics And Fishery Dynamics Of Red Drum (Sciaenops Ocellatus), In The North-Central Gulf Of Mexico, Corbin Bennetts

Master's Theses

Red Drum (Sciaenops ocellatus) are highly targeted recreationally in the Gulf of Mexico, and support a small commercial fishery in Mississippi. Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy …

Growth And Reproduction Of Atlantic Chub Mackerel (Scomber Colias) In The Northwest Atlantic, Taylor T. Daley

Master's Theses

Recent efforts to manage Atlantic Chub Mackerel (Scomber colias) in the northwest Atlantic have necessitated the description of the stocks life-history characteristics. The purpose of this study was to address the absence of regional information on growth and reproduction. Growth models were fit in a Bayesian framework. The length-at-age relationship was described using four non-linear candidate growth models, which were fit to total length (TL, cm) and age estimates (y). Age estimates were derived from whole otoliths for adults (n = 422) and ages of one month were assigned to larval fish (n = 60). The …

Factors Influencing Ectoparasitism On Western Fence Lizards (Sceloporus Occidentalis): Host Sex, Testosterone, Reproductive Condition, And Behavior, Nicholas B. Pollock

Master's Theses

Host-parasite relationships are one of the most common symbiotic relationships present in a diverse array of ecosystems. There are numerous factors that impact the dynamics of these relationships. Major factors that can influence the degree of parasitism include host sex, hormonal state, reproductive condition, and behavior. It has been observed in several vertebrate taxa that males have higher ectoparasite intensities than females and males with increased testosterone have increased ectoparasite intensities. One potential reason for these observations is that testosterone concentrations are elevated in males, particularly during the breeding season, and when circulating concentrations increase males become more vulnerable to …

Life History Characteristics Of The Starry Skate, Raja Stellulata, From California Waters, Kelsey James

Master's Theses

The order Rajiformes, or skates, is a morphologically conservative group that exhibits a wide range of life history characteristics. This inter-species variability warrants species-specific research. This study investigates the age, growth, reproduction, and habitat of the Starry Skate, Raja stellulata, which is endemic to the U.S. West Coast. Age and growth parameters were determined using two preparation techniques: gross sectioning and histological sectioning. The assumption that gross sections deposit one band pair a year was indirectly validated with centrum edge analysis and marginal increment ratio. It was not indirectly validated with histological sections. Age estimates from gross sections ranged from …

Reproductive Experience And Aging : Possible Neuroprotective Effects Of Motherhood, Jessica Dawn Gatewood

Master's Theses

Hormonal fluctuations associated with pregnancy and post partum periods create significant changes in the brain and behavior in female rats. Animals were tested in a land version of the Morris Water maze for three days at 6, 12, 18 and 24 months. At the ages of 12, 18, and 24 months animals were also tested in the same maze using a reversal task. At the conclusion of the study brains were analyzed for Amyloid Precursor Protein (APP) to determine the amount of neurodegeneration among the groups. Multiparous animals showed significantly superior performance , followed by primiparous animals, and nulliparous animals …

Relationships Of Epidermal Morphology And Breeding Behaviors In Pebble Nest-Building Minnows (Pisces: Cyprinidae), William R. Mcguire

Master's Theses

Abstrad The objective of this study was to determine if epidermal morphology corresponds with reproductive behavior in cyprinid fishes. Representative species of nest-building fishes (Nocomds leptocephalus, Semotilus atromeculatus, exoglossum maxillingua) and non nest-building fishes (Campostoma anomaulm and Clinostomus funduloides) were studied. Light and scanning electron microscopy were used to examine epidermal morphology and keratin distribution of skins from the snout, cheek, mandible, anterior dorso-lateral trunk, and caudal peduncle of breeding males of nest-building species and were compared to those in non nest-building cyprinid species. Previous frame-by-frame analysis of video tapes of reproductive activities of each species and literature accounts were …

Spawning Clasps And Gamete Deposition In Pebble Nest-Building Minnows (Pisces : Cyprinidae), Mark Henry Sabaj

Master's Theses

Spawning in five species of North American cyprinid minnows (Rhinichthys a. atratulus, Exog/ossum laurae, Semotilus atromaculatus, Nocomis leptocephalus, and N. micropogon ) are analyzed on videotape filmed in Virginia and Maryland streams. Behaviors are chronologically resolved into a sequence of categories (Interim, Approach, Alignment, Run, Clasp and Dissociation) exemplary of a successful spawn as defined by the clasp. The categories are used to describe spawning behaviors in each species. In all species studied, a successful spawn is a female initiated event effecting the clasping response of a male.

The species-specific pattern of male-female interactions not only reflects the coordination of …

The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of The Male Mongolian Gerbil (Meriones Unguiculatus), Luis Jose Cova Marchan

Master's Theses

This work was undertaken to study the effects of photoperiod and melatonin on fertility in male Mongolian gerbils (Meriones unguiculatus). Four groups of fifteen animals each, were placed in different photoperiods (ambient, ranging from 14L:10D to 11.3L:12.3D; 24L:10D; 14L:10D; and 1L:23D). After 35 days, three gerbils from each photoperiod condition were sacrificed and the testes, epididymides, seminal vesicles, prostate, kidneys, adrenals, thymus and hypophysis were weighed. The testes and epididymides were placed in Bouin's fixative and used for histological studies. Also, two males from each photoperiod condition were paired individually with a female. The remaining animals of each photoperiod condition …

The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Male Mice, Mus Musculus, Icr Strain, Margaret Ann Shugart

Master's Theses

The reproductive effects of long (24L:OD), natural (14L:lOD), and short (1L:23D) photoperiods were studied in the male mouse, Mus musculus, ICR strain. One third of the mice in each photoperiodic regimen were sacrificed after 45 days. Half of the remaining mice in each regimen received daily melatonin (5-methoxy-N-acetyl tryptamine) injections for 45 additional days. Body weights, testicular and accessory sex organ weights were measured and microscopic examinations of the testes were made. Plasma testosterone levels were determined using radioimmunoassay. Other organ (pituitary, kidney, adrenal, thymus, thyroid) weights were also obtained.

The Effect Of Photoperiod On The Regressive Phase Of The Ovarian Cycle Of The Lizard, Anolis Carolinensis., John Dickens Pinch

Master's Theses

The effects of constant photoperiod (14 hours of light) and decreasing photoperiod (13-8 hours of light) on the regressive phase of the ovarian cycle of the lizard Anolis carolinensis were investigated. Changes in body, liver, ovary and oviduct weights were measured and microscopic examinations of several ovarian parameters were made. In both light regimens body and liver weights decreased over the first four weeks of the experiment but both increased at the sixth week. In addition, ovary weight was highly variable but exhibited a decreasing trend and oviduct weight decreased. There were decreases in the number of previtellogonic follicles and …