Background & Objectives: Arthropods have neurogenic hearts, which have pacemakers as part of the nervous system found outside the heart. Vertebrates and molluscs have myogenic hearts, where the pacemaker is composed of specialized cardiac muscle within the heart. Daphnia is unique as it is a cladoceran crustacean reported to have a myogenic heart. To test this, use drugs known to change heart rate in myogenic hearts and observe if they have the same influence on Daphnia.
Methods: Used a modified pipette to retrieve Daphnia from cultured jar, then immobilized Daphnia in minimal amount of Vaseline on a depression slide. Obtained new Daphnia for each treatment and recorded baseline heart rate in aged water. In a double-blinded procedure, measured
Methods: Used a modified pipette to retrieve Daphnia from cultured jar, then immobilized Daphnia in minimal amount of Vaseline on a depression slide. Obtained new Daphnia for each treatment and recorded baseline heart rate in aged water. In a double-blinded procedure, measured