Analysis of spatial niche structure in coexisting tidepool fishes: null models based on multi-scale experiments

Area of Science:

• Marine Ecology
• Behavioral Ecology
• Community Ecology

Background:

• Understanding species interactions is crucial for predicting community structure.
• Spatial niche partitioning is a key mechanism for coexistence in species-rich environments.
• Intertidal ecosystems are dynamic and subject to strong biotic and abiotic influences.

Purpose of the Study:

• To investigate how interspecific interactions modify fundamental and realized spatial niches in three intertidal gobiid species.
• To assess spatial niche use and coexistence at both microhabitat and habitat-wide scales.
• To determine if null models can predict spatial overlap and coexistence patterns.

Main Methods:

• Laboratory and mesocosm experiments combined with field observations.
• Null model analysis to compare observed spatial use with random expectations.
• Single-species and multi-species (intraspecific and interspecific) treatments were employed.

Main Results:

• Microhabitat use patterns differed between single and paired species treatments.
• Interspecific interactions reduced tidepool occupancy for two Chaenogobius species.
• Spatial overlap was lower than expected in interspecific combinations, suggesting niche differentiation.

Conclusions:

• Species interactions significantly modify spatial niches of intertidal fishes.
• Null models are effective tools for deciphering changes in niche structure and predicting coexistence.
• A potential trade-off between competitiveness and growth efficiency may influence gobiid fish interactions.