Meeting Abstract
While there is an abundance of literature addressing how starvation resistance causes biological tradeoffs, such as changes in longevity, fecundity, and cell death, there is surprisingly little research addressing the role of evolutionary change in regulating this critical metabolic process. The Naidids are a family of Annelids (segmented worms) that have independently lost the ability to regenerate a head (anterior regeneration) 3 separate times. We attempt to determine if there is a correlation between the ability to regenerate a head (anterior regeneration) and starvation resistance. To gain insight into the physiological processes used to overcome stress, we assess worm metabolic rate under caloric restriction. Due to the size of Naidid worms (typically less than 8 mm in length), traditional analysis using dissolved gas probes is largely ineffective at reliably recording Annelid metabolic processes. Using a Membrane Inlet Mass Spectrometer (MIMS), we measure the depleting O2 and increasing CO2 levels in laboratory worm cultures. Median survival time is determined under starvation conditions for 7 species of Naidids: 4 anterior regenerating and 3 non-anteriorly regenerating, in cut and uncut worms, and at 2 different temperatures. Resistance to starvation varies considerably among species and across temperatures. We found that starvation resistance is, usually, similar across cut and uncut Naidids and present other possible correlates of starvation resistance, including rate of wound healing, fission rate, and lifespan of posterior zooid.
