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Full-Text Articles in Life Sciences

Osmoregulation And Appetite Regulation In A Basal Vertebrate, The Sea Lamprey (Petromyzon Marinus), Jessica Norstog Nov 2023

Osmoregulation And Appetite Regulation In A Basal Vertebrate, The Sea Lamprey (Petromyzon Marinus), Jessica Norstog

Doctoral Dissertations

Lamprey (Petromyontiformes) are the oldest extant family in the vertebrate lineage, providing a unique phylogenetic position for studies on vertebrate evolution. As a basal vertebrate, sea lamprey (Petromyzon marinus) is an important species to understand evolution and comparative physiological mechanisms, including osmoregulation and appetite regulation. Sea lamprey has anadromous (native to the Atlantic Ocean) and landlocked (invasive in the Laurentian Great Lakes in North America) populations. In both populations of sea lamprey, the blind filter-feeding freshwater (FW) larvae burrow in stream sediments for until undergoing a hormonal-driven metamorphosis. During this phase, sea lamprey do not feed as major …


Temperature Effects On Growth And Stress Physiology Of Brook Trout: Implications For Climate Change Impacts On An Iconic Cold-Water Fish, Joseph G. Chadwick Jr Jan 2012

Temperature Effects On Growth And Stress Physiology Of Brook Trout: Implications For Climate Change Impacts On An Iconic Cold-Water Fish, Joseph G. Chadwick Jr

Masters Theses 1911 - February 2014

Despite the threat of climate change, the physiological mechanisms by which temperature drives the distribution of species are unclear. Here we used chronic temperature exposures to determine that the upper limit for positive growth in the eastern brook trout (Salvelinus fontinalis) is 23.4 °C. Additionally, brook trout exposed to daily temperature oscillations of 8 °C, around a mean of 21 °C, exhibited growth rates that were 43 and 35% lower by length and weight respectively, than in constant 21 °C controls. Limitations in growth were associated with increases in indicators of the physiological stress response. Individuals exposed to …


Food-Limited Growth And Condition Index In The Eastern Oyster, Crassostrea Virginica (Gmelin, 1791), And The Bay Scallop, Argopecten Irradians Irradians (Lamarck, 1819), Michael A. Rice, Robert B. Rheault Jr. Dec 1995

Food-Limited Growth And Condition Index In The Eastern Oyster, Crassostrea Virginica (Gmelin, 1791), And The Bay Scallop, Argopecten Irradians Irradians (Lamarck, 1819), Michael A. Rice, Robert B. Rheault Jr.

Michael A Rice

The growth response of the eastern oyster, Crassostrea virginica, and the bay scallop, Argopecten irradians irradians, to varying degrees of food limitation was evaluated. Under conditions of low current speed, dense assemblages of shellfish can rapidly deplete ambient food concentrations, resulting in measurable effects on growth and condition index. A flume study demonstrated significant growth and condition index responses to resource competition after reductions as small as 27% in relatively high ambient food concentrations (—4.6 u.g/1 chlorophyll). Growth rates and condition index are linearly correlated with the average chlorophyll ration consumed. A field study demonstrated similar growth responses when the …