Light quality induces a shift in coccosphere morphology in Scyphosphaera apsteinii

Area of Science:

• Marine biology
• Phycology
• Biogeochemistry

Background:

• Coccolithophores are key marine phytoplankton that form calcium carbonate plates (coccoliths).
• Schyphosphaera apsteinii exhibits unique coccolith morphotypes, specifically lopadoliths.
• Coccolith production is influenced by environmental factors, including light.

Purpose of the Study:

• To investigate the acclimated effects of light intensity and wavelength on Schyphosphaera apsteinii cell physiology and coccosphere morphology.
• To understand the relationship between light conditions and lopadolith production.

Main Methods:

• Culturing Schyphosphaera apsteinii under varying light intensities (reduced vs. replete) and wavelengths (blue vs. red).
• Measuring cell physiology parameters: growth rates, chlorophyll concentration, and net photosynthetic rates.
• Analyzing coccosphere morphology, focusing on lopadolith production.

Main Results:

• Reduced light intensity significantly increased lopadolith production, accompanied by lower growth rates but higher chlorophyll and net photosynthetic rates.
• Reduced blue light also led to increased lopadoliths, chlorophyll, and net photosynthesis.
• Reduced red light showed less pronounced responses compared to blue light.
• Both reduced blue and red light conditions resulted in enhanced growth rates compared to the control, despite lower light intensity.

Conclusions:

• Light intensity and wavelength significantly impact Schyphosphaera apsteinii physiology and coccolith morphology.
• Increased lopadolith production under reduced light, particularly blue light, may be an adaptation for improved light harvesting.
• Changes in coccosphere morphology are linked to physiological adjustments for optimizing photosynthesis under varying light conditions.