Physiological Response of Elasmobrachs During Propofol Immersion

Sensory experiments require anesthesia so the animal is immobilized, however fish anesthetics have shown to depress sensory responses. Newer anesthetics may offer similar anesthetic relief, but differ in means of action so sensory responses may be unaffected. Propofol has been used intravenously on small elasmobranchs but may provide prolonged effects if used as an immersion anesthetic. Objectives of this study were 1. Determine appropriate concentration of anesthetic to minimize induction and recovery for animals anesthetized at a surgical plane of anesthesia and 2. Measure physiological response of the pupil to light stimuli during anesthetic immersion. To address these objectives, I used the coral catshark (Atelomycterus marmoratus) and the Atlantic stingray (Hypanus sabinus). Ventilation rate and reflex responses were recorded to measure induction and recovery in increasing concentrations of tricaine and propofol. Appropriate concentrations of anesthetics are approximately 160 and 1.4, and 140 and 0.7 mg L-1of tricaine and propofol in A. marmoratus and H. sabinus, respectively. After 1.5 hours of dark adaptation in anesthetic (50, 100, or 150 mg L-1 tricaine or 0.5, 1, or 1.5 mg L-1 propofol) or no anesthesia (control), tricaine 100 mg L-1 trials show reduction in percent pupil constriction (p-1 trials in Atlantic stingrays (p-1 of propofol (p anesthetized using 1.5 mg L-1of propofol (