Meeting Abstract
P3.126 Thursday, Jan. 6 Effects of Acclimation and Aeration on Stress Responses in Blackworms IBRAHIM, Ghaith*; KAEHLER, Amanda; HRANITZ, John; SURMACZ, Cynthia; Bloomsburg University; Bloomsburg University; Bloomsburg University; Bloomsburg University csurmacz@bloomu.edu
The aquatic worm Lumbriculus variegatus is a model organism for toxicity testing and ecological risk assessment in freshwater systems. In addition to being a low-level consumer in lentic food webs, blackworms are inexpensive, easy to maintain, sensitive to various toxins, and display readily observable biological responses such as pulse rate and tactile responses. Our goal is to calibrate several commonly used behavioral and physiological stress measures against a cellular stress marker in this species. In pilot studies, HSP70 levels were significantly elevated in worms exposed to heat shock or chemical pollutants. To use HSP70 to monitor the health of aquatic ecosystems, standard conditions for worm care and maintenance prior to and during experiments need to be established. Our objective in this experiment was to examine two factors that may affect HSP70 responses in our studies of blackworms: aeration and acclimation time. For one month, we sampled blackworms weekly and subjected them to 3-h incubation at room temperature and heat stress (36.5oC) with gentle aeration, except for week four when worms were subdivided into aerated and non-aerated treatments. HSP70 concentrations were not affected by acclimation time (P=0.818) or heat shock (P=0.344) when worms were aerated. An interaction between aeration and heat stress (P=0.005) affected HSP70 concentration in blackworms. HSP70 concentrations of control and heat shock worms were similar when aerated but differed when not aerated. These findings suggest that stress responses were similar in blackworms over a 4-week acclimation period but, because aeration interfered with stress response measurement, blackworms should be maintained under non-aerated conditions in future studies.
