New 🐟 Mercury Safety Guide & Omega-3 Rankings Updated for 2026. View Omega-3 Rankings →

🌊
Feeding Behavior

Filter Feeding

Straining plankton, small crustaceans, and detritus from massive volumes of water using gill rakers and modified mouthparts.

Trigger: Food Function: Efficient harvest of dispersed plankton and organic matter

📖 Overview

The largest fish on Earth - whale sharks, basking sharks, manta rays, megamouth sharks - are all filter feeders. Bypassing higher trophic levels and feeding directly on plankton is astonishingly efficient - it lets these giants reach 12+ metres and thousands of kilograms on a diet of microscopic prey. Smaller filter feeders like menhaden, anchovies, and paddlefish are the ecological linchpins between plankton and predators.

⚙️ How It Works

Ram filtration (swimming with mouth open - whale shark, basking shark). Suction filtration (gulping and expelling water through gill rakers - anchovies). Buccal pumping (pumping water without swimming - some rays).

🐟 Examples Across Species

Whale shark, basking shark, megamouth shark, manta ray, paddlefish, menhaden, anchovies, silver carp, gizzard shad.

Fun Fact

A whale shark can filter 1,500 gallons of water per hour - the volume of a hot tub every hour. Its gill rakers are so fine they can retain organisms less than a millimeter across.