TEMPERATURE AND LOCOMOTION IN PLANARIA.

Area of Science:

• Physiological Ecology
• Animal Behavior
• Biochemistry

Background:

• Locomotion in animals is influenced by temperature.
• Previous studies (Crozier, Glaser) established thermal increments for various animal activities.
• Planarian locomotion exhibits temperature-dependent characteristics.

Purpose of the Study:

• To investigate the temperature characteristics and thermal increments of Planarian locomotion.
• To determine the underlying metabolic processes controlling Planarian movement at different temperatures.
• To assess the impact of feeding on these temperature-dependent responses.

Main Methods:

• Analysis of thermal increments (Arrhenius plots) for Planarian locomotion across a temperature range.
• Comparison of observed thermal increments with known values for catalyzed oxidative reactions.
• Observation of locomotion changes following feeding events.

Main Results:

• Three distinct thermal increments (micro = 7,000-8,000, 11,100, and 18,000-22,000) were identified, controlling locomotion at different temperature ranges.
• The lowest increment dominates above 20-22°C, the intermediate at 13-21°C, and the highest below 13°C.
• Feeding temporarily modifies the thermal increment in the median temperature range for up to two days.

Conclusions:

• Planarian locomotion is regulated by multiple metabolic processes with distinct temperature sensitivities.
• Respiration, a catalyzed oxidative reaction, is likely the primary determinant of locomotion rate.
• Feeding introduces a temporary metabolic shift affecting temperature-dependent locomotion.