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Full-Text Articles in Life Sciences
The Effect Of 6-Methoxybenzoxazolinone On Reproductive Condition In The Hispid Cotton Rat, Sigmodon Hispidus, Vera Lee Adams
The Effect Of 6-Methoxybenzoxazolinone On Reproductive Condition In The Hispid Cotton Rat, Sigmodon Hispidus, Vera Lee Adams
Biological Sciences Theses & Dissertations
A non-estrogenic hormone, 6-methoxybenzoxazolinone (6-MBOA), found in young growing grasses, has been shown to be a reproductive initiator in several herbivorous rodents. However, the mechanism by which 6-MBOA initiates reproduction has not been determined. Many believe that 6-MBOA represents a reliable cue that the vegetative growing season has begun, but it is unknown whether this hormone is a primary cueing mechanism or if it works in conjunction with other environmental factors. Therefore, a controlled laboratory experiment was conducted using male and female Sigmodon hispidus, the hispid cotton rat, to determine whether different dosages of 6-MBOA (4μg, 40 …
Pheromonal Composition Of Two Species Of African Amblyomma Ticks: Similarities, Differences And Possible Species Specific Components, Thomas Lem Price Jr.
Pheromonal Composition Of Two Species Of African Amblyomma Ticks: Similarities, Differences And Possible Species Specific Components, Thomas Lem Price Jr.
Biological Sciences Theses & Dissertations
Two species of bont ticks, Amblyomma hebraeum and Amblyomma variegatum, common to Africa have been studied to compare types and quantities of compounds known or believed to serve as components of the attraction-aggregation-attachment pheromone (AAAP). A complex of attraction, aggregation and attachment pheromones are used by these ticks to detect hosts, mates and perhaps minimize interspecific breeding. Solvent extraction of pheromone emitting ticks followed by Gas Chromatography and Mass Spectrometry revealed little difference in the composition of the AAAP in these two species. However, subtle differences in the relative makeup of the pheromonal blend are noted, suggesting that such differences …
Evaluation Of The Gross Anatomy Seasonal Changes Function And Histology Of The Perineal Gland In The Hispid Cotton Rat, Sigmodon Hispidus, Julie Anne Winchell
Evaluation Of The Gross Anatomy Seasonal Changes Function And Histology Of The Perineal Gland In The Hispid Cotton Rat, Sigmodon Hispidus, Julie Anne Winchell
Biological Sciences Theses & Dissertations
The perinea! gland in the hispid cotton rat, Sigmodon hispidus, is a seasonally cyclic, subcutaneously located organ which is associated with the reproductive system. On gross dissection, the gland possesses a strong attachment to the penis with only loose fascia! connections to the rectum and surrounding muscle and skin. Histologic exam confirms this connection to the reproductive tract and shows the organ to be a compound tubuloacinar gland with a projection leading into the penis. The cyclic hypertrophy and regression of the gland closely parallels that of the testes and seminal vesicles indicating that this cyclicity may be under …
Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri
Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri
Dissertations, Theses, and Masters Projects
Otoliths, scales, dorsal spines, and pectoral fin rays, of Atlantic croaker, Micropogonias undulatus, were compared for legibility of presumed annuli and precision in repeated readings, to determine the best structure for ageing. Marks on transverse otolith sections were easiest to read and showed the best agreement between readings. Fish collected in Chesapeake Bay and in Virginia and North Carolina coastal waters during 1988-1991 were then aged using otolith sections. Ages 1-8 were recorded, but eight-year-old fish were rare. Marginal increment analysis showed that for ages 1-7 annuli are formed once a year during the period April-May. Otolith age readings were …
The Structure Of The Holocephalan Head And The Relationships Of The Chondrichthyes, Eileen D. Grogan
The Structure Of The Holocephalan Head And The Relationships Of The Chondrichthyes, Eileen D. Grogan
Dissertations, Theses, and Masters Projects
The interrelationship of the chondrichthyan subclasses is evaluated based on divergence in the nature of the suspensorium, the preorbital cranial anatomy, the distribution of major venous sinuses and localization of hematopoietic tissue. The anatomy of representative extant taxa was examined by radiography and/or dissection. Fossil selachians, paraselachians, and holocephalans of the Bear Gulch of Montana, U.S.A. (Mississippian, Namurian E2B) were studied for evidence of vascular pigmentation, suspensorium, and cranial, branchial, and pectoral anatomy. These studies validate the suspensorial condition of autodiastyly and suggest autodiastyly is a fundamental condition involved in the basic radiation of Chondrichthyes. The plesiomorphous condition of all …
Phylogenetic Relationships Within The Batagur Complex (Testudines: Emydidae: Batagurinae), Jean M. Capler
Phylogenetic Relationships Within The Batagur Complex (Testudines: Emydidae: Batagurinae), Jean M. Capler
Masters Theses
Relationships between 10 species of the batagurine genera Batagur, Callagur, Kachuga, Hardella, and Morenia are discussed based on a cladistic analysis of 35 morphological characters. Ocadia sinensis (Emydidae: Batagurinae) was used as the outgroup species. Four cladograms were produced with a length of 59.0 steps and a 0.75 consistency index. In contrast with previous studies, Hardella and Morenia do not appear as a monophyletic clade. Instead, Hardella is included with the remaining ingroup taxa (exclusive of Morenia) based on five synapomorphies. The present genus Kachuga was determined to be paraphyletic, having excluded the present genera Batagur and Callagur. The pangshura …
Biotic, Abiotic, And Behavioral Patterns Associated With The Nocturnal Movements Of Shrews, Patrick T. Sullivan
Biotic, Abiotic, And Behavioral Patterns Associated With The Nocturnal Movements Of Shrews, Patrick T. Sullivan
Masters Theses
Thirteen trails left by shrews coated with fluorescent powder were examined for microhabitat documentation. Thirteen data parameters were collected from each trail, two of which differed significantly between Blarina brevicauda and Sorex longirostris. The small soricid Sorex longirostris was captured in areas with higher grass content, and lower wooded content, than the larger Blarina brevicauda. The difference in microhabitat use may be a key mechanism in reducing competition between these two species.
Ecology Of The State Endangered Yellow Mud Turtle, Kinosternon Flavescens In Henry Co., Illinois, Michael W. Tuma
Ecology Of The State Endangered Yellow Mud Turtle, Kinosternon Flavescens In Henry Co., Illinois, Michael W. Tuma
Masters Theses
Illinois populations of the state endangered yellow mud turtle (Kinosternon flavescens) persist in scattered locations on sand prairies. The largest population occurs on a remnant sand prairie of the former Green River Marsh in Henry Co. A study was conducted during 1992 to determine important criteria for preserve design. These criteria included extent of turtle movements within the site and habitat use. Turtles were captured by aquatic hoop traps, drift fence, and by hand from May 11 to August 31. A total of 16 adults, four juveniles, and eight hatchlings were captured. Population size was estimated at 44.80 adults using …