Differential resource use in filter-feeding marine invertebrates

Area of Science:

• Marine ecology
• Community ecology
• Interspecific competition

Background:

• Coexistence theory suggests more resources promote species coexistence.
• Marine invertebrate communities traditionally focused on space as the sole limiting resource.
• Planktonic food is a recognized resource, but its niche structure is debated.

Purpose of the Study:

• To investigate if planktonic food represents a single resource niche or multiple, differentially utilized niches.
• To determine if resource specialization influences coexistence in marine invertebrate communities.

Main Methods:

• Quantified consumption rates of three distinct phytoplankton species by 11 marine invertebrate species.
• Analyzed variation in consumption rates to identify patterns of resource utilization.

Main Results:

• Consumption rates varied significantly (240-fold difference) across consumer-phytoplankton pairs.
• Evidence of differential resource usage, with most consumers showing preference for specific phytoplankton species.
• No single consumer ingested all phytoplankton types at equivalent rates.

Conclusions:

• Phytoplankton niche utilization by filter feeders is more subdivided than previously assumed.
• Resource specialization and niche partitioning likely play a key role in facilitating marine invertebrate coexistence.
• Findings offer a mechanism linking biodiversity, community function, and invasion dynamics.