Positive interspecific associations consistent with social information use shape juvenile fish assemblages

Area of Science:

• Ecology
• Behavioral Ecology
• Ichthyology

Background:

• Social information from other species enhances fitness by reducing environmental uncertainty.
• Mixed-species grouping is common in fish, particularly among juveniles, suggesting greater adaptive value during this developmental stage.
• Juvenile fish exhibit greater niche overlap due to similar body sizes, increasing the relevance of heterospecific cues for predation risk and resource location.

Purpose of the Study:

• To investigate the role of social information in shaping juvenile fish assemblages.
• To determine if nonrandom associations among juvenile fish are driven by interspecific information use.
• To identify key species that influence assemblage structure through information provision.

Main Methods:

• Employed a joint species distribution model (JSDM) to analyze fish co-occurrence data from 785 seine hauls.
• Accounted for species-environment relationships to isolate interspecific associations.
• Utilized remote underwater video surveys for qualitative behavioral data.

Main Results:

• Detected significant positive associations among 84% of species pairs, primarily within mutual foraging guilds.
• Observed affiliations between species that have neutral or negative interactions in later life stages.
• Identified Eucinostomus spp. as a key species, significantly influencing assemblage structure through information production.

Conclusions:

• Positive interactions driven by information exchange are principal factors organizing local juvenile fish assemblages.
• Ontogeny mediates the relevance and exploitation of social information across species.
• Interspecific information use is a critical factor in the behavioral ecology of juvenile fishes.