Energy Content of Kentucky Snubnose Darter Eggs

The Kentucky Snubnose Darter (Etheostoma rafinesquei) occurs only in the upper Green River drainage in Kentucky.  Dr. Weddle has studied the reproductive ecology of this species extensively (click here for a paper).  This species of darter spawns several batches of eggs over a period of about two months from March through early May, producing a new batch about every three to four days.  Initially, the number of eggs produced is quite small, but this number grows substantially reaching a peak in late April and then declining rapidly thereafter.  The pattern of egg-laying approximates an convex curve over time.  We are investigating this pattern in an attempt to understand it.  We want to know how much energy a female darter expends on egg production and whether this energy differs during the spawning season.  Laura Webb is working with Dr. Weddle to address this question, by measuring the caloric content of eggs produced at different times.  We will be measuring caloric content with an instrument borrowed from the chemistry department which measures the amount of heat produced following ignition of a weighed sample of eggs (oxygen bomb calorimeter).  This research should allow us to better understand spawning patterns of darters in general.  If interested in helping with field or laboratory work contact Laura or Dr. Weddle