Deep-Pelagic Fishes Are Anything But Similar: A Global Synthesis

Area of Science:

• Marine Biology
• Deep-Sea Ecology
• Ichthyology

Background:

• Deep-pelagic fishes are abundant vertebrates vital for carbon sequestration and marine food webs.
• Current knowledge is fragmented, hindering effective conservation and management strategies.
• Existing ecological models often oversimplify the functional and ecological diversity of these fish.

Purpose of the Study:

• To synthesize global data on deep-pelagic fish biodiversity and ecology.
• To develop a new semantic framework for classifying deep-pelagic fishes.
• To propose a conceptual model for understanding their ecological transitions.

Main Methods:

• Comprehensive review of pelagic ecosystem classifications and sampling methods.
• Assessment of global deep-pelagic fish fauna, identifying 1554 species.
• Analysis of morphological, behavioral, and ecological diversity.

Main Results:

• Identified 1554 species of deep-pelagic fishes globally, revealing significant regional variability.
• Demonstrated substantial morphological, behavioral, and ecological diversity within this group.
• Highlighted the limitations of current ecological models in representing these fish.

Conclusions:

• Deep-pelagic fishes are highly diverse and not ecologically homogeneous.
• A more realistic approach is needed to understand their ecology, especially during diel vertical migrations.
• Introduced the 'diel-modulated realised niche' concept to model ecological transitions.