Fig. 7.

Comparison of body distention following a blood meal with the increase in the probability of swimming following feeding. (A) Gain in mass, essentially a conversion of the blood meal into body mass, was measured by weighing individual leeches before the one-time feeding and then again after removing all the blood from their guts at various times following the feeding. (B) Body distention (mass of blood remaining after a meal/total mass of blood ingested during a meal) as a function of days since feeding. (C) The rate of swimming (collapsed over all water depths; replotted from Fig. 4B) that occurs following feeding to satiation on blood as a function of days since the feeding. (D) Swim behavior, as a percentage of the total number of behaviors, plotted against distention. Line is best linear fit to the data (R=−0.065, P=0.03).