(full paper is archived in the Miller Library)
Title: Diurnal pattern of ammonia release in a marine isopod, Cirolana harfordi (Lockington, 1876)
Student Author(s): Harbaugh, Robert D.
Faculty Advisor(s): Phillips, John H.
Location: Final Papers Biology 175H
Date: June 1973
Abstract: 1. An inverse exponential relationship between ammonia excretion as expressed in ng NH3/mg dry body weight/hr when plotted as a function of dry body weight (mg) has been established in Cirolana harfordi, a marine isopod. 2. A diurnal pattern of ammonia excretion has been detected in specimens of C. harfordi exposed to a normal light/dark photoperiod. 3. Non-fed members of a C. harfordi population exhibit a dampened pattern of diurnal ammonia release and appear to excrete less total ammonia per unit tissue weight over a 24-hour period than do fed individuals. 4. Conditions of constant light or constant dark do not remove the observed pattern of diurnal ammonia release. Continuous light dampens the daily excretion rhythm and appears to cause a diminution in ammonia excretion rates observed over a 24-hour period.