Biology Commons^™

Buoyancy Changes As Related To Respiratory Behavior In An Amphibious Snail, Pomacea Urceus (Müller), From Venezuela, Kathleen A. Burky, Albert J. Burky

Biology Faculty Publications

The ampullariid Pomacea urceus uses its ctenidium and lung in respiration. The snails reach the surface with their siphon and ventilate their lung by withdrawing their head-foot in a pumping action. The lung gas also serves to change the buoyancy of the snails. After a ventilation a snail does not necessarily return to the same buoyancy level. They may achieve overall specific gravities of <1 to > 1 after a ventilation. They may remain submerged (s.g. > 1) or float (s.g.

The Effect Of Cv-1 Cell Geometry On The Ultraviolet Radiation Sensitivity Of Mammalian Cells In Vitro, Daniel J. Knauer

Masters Theses & Specialist Projects

The effect of cell geometry on the radiosensitivity to ultraviolet (UV) light has been studied in the CV-1 host cell-capacity system. In this system the macromolecular damage incurred by monolayers of cells cultures as the result of exposure to UV radiation is monitored by testing the ability of irradiated cells to support the replication of Herpes simplex virus. The target molecule has been shown to be DNA and is centrally located

Mammalian cells have an absolute requirement for Mg⁺⁺ and Ca⁺⁺ in order to remain attached to artificial substrata. To test the effect of cell geometry on UV …

Localization Of Neurosecretory Cells Within The Cerebral Ganglia Of Amphiphorus Imparispinosus Griffin, 1898 (Hoplonemertea) And Their Possible Regulatory Role In The Annual Reproductive Cycle, Gail H. Jacobson

Dissertations and Theses

Nemerteans are common invertebrates along coastlines in both temperate and arctic climates throughout the world. Amphiphorus imparispinosus is a carnivorous member of this phylum that is found abundantly in the intertidal areas of the Oregon coast. As in many other invertebrate phyla, endocrine integration within the nemerteans is thought to be accomplished by neurosecretory mechanisms. In Amphiphorus the presence of these neurosecretory systems has not been previously shown. This project was undertaken to determine if neurosecretory cells are present within the central nervous system of this species and. further, to examine seasonal changes in the number and appearance of these …

The Dispersal And Dispersion Patterns Of Hydra Fusca In A Limited Environment, Faith E. Ruffing

Dissertations and Theses

The dispersal and dispersion patterns of Hydra fusca were examined. Hydra were placed in petri dishes at various densities. The water in the dishes was swirled forcing the animals to the center. The location of each animal was marked at time intervals thereafter. Analyses of the dispersal rates and dispersion patterns were made. Hydra dispersed from a central release point at a non-random rate. There was rapid movement from the center followed by a minimal daily movement. This eventually resulted in a uniform dispersion pattern at high densities in a limited environment. There was a relationship between the ratio of …