Meeting Abstract
Many animals possess the remarkable ability to regenerate body parts lost to injury. In the Naididae, a family of aquatic annelids, some species can regenerate lost anterior and posterior ends, while others can only effectively regenerate posteriorly. Little is known in this group about the physiological responses to injury, how these differ following anterior and posterior injury, and how the beginning stages of anterior or posterior regeneration alter organismal physiology in stressful environmental conditions, such as extreme temperature. In this study, we subjected individuals of the naidid Pristina leidyi to posterior- or anterior-end amputation and placed them within a range of environmentally-relevant ambient temperatures. We determined acute thermal tolerance ranges and LT50s for each injury state by assessing short-term survival. We then measured O2 consumption of surviving individuals via membrane inlet mass spectrometry (MIMS); experiments assaying lipid content and heat shock protein expression are ongoing. Current data indicate that the ability to tolerate low temperature, but not high temperature, differs between injury states. Rate of O2 consumption per unit mass appears reduced following injury across the range of temperatures and is lower overall following anterior amputation versus posterior. The temperature at which O2 consumption is maximal also differs between injury states. Our results provide insight into how injury and regeneration alter physiological state, including while coping with additional physiologically-demanding stressors. Furthermore, they suggest that injury and early regeneration at the anterior end have a more substantial impact than at the posterior end.
