OXYGEN UPTAKE OF THE SOLITARY TUNICATE STYELA PLICATA

Area of Science:

• Marine Biology
• Animal Physiology
• Ecology

Background:

• The solitary tunicate Styela plicata is a marine invertebrate with a significant ecological presence.
• Understanding its metabolic maintenance costs is crucial for predicting its distribution and reproductive success.

Purpose of the Study:

• To quantify the routine metabolic costs of Styela plicata throughout the year.
• To investigate the influence of body weight and temperature on oxygen consumption.
• To determine if high metabolic costs limit reproduction during warmer months.

Main Methods:

• Measurement of oxygen consumption in acclimatized Styela plicata across various temperatures.
• Analysis of the relationship between oxygen consumption, body weight, and temperature.
• Assessment of critical oxygen tension as a function of temperature and body size.

Main Results:

• Oxygen consumption is proportional to the 0.7 power of body weight, irrespective of acclimatization temperature.
• Q10 values (temperature sensitivity) decrease with rising temperatures.
• High metabolic costs do not explain the lack of reproduction in summer; winter mortality appears to limit the northern range.

Conclusions:

• Routine metabolic costs are primarily influenced by body size rather than temperature fluctuations within the tested range.
• Winter mortality, potentially due to dislodgement during cold periods, is a key factor limiting the northern distribution of Styela plicata.
• Ciliary and filter-feeding activities influence oxygen uptake dynamics, particularly at higher temperatures and larger body sizes.