Live Calci Worms
for fish — koi,
pond & aquarium.

Why live BSFL for fish?

Live BSFL are a natural prey item for many fish species in the wild — particularly surface-feeding fish that take invertebrates falling from vegetation above water. Their wriggling movement triggers predatory feeding responses, making them significantly more stimulating than pellets or dried food.

Nutritionally, live BSFL offer approximately 42% protein and 29% fat on a dry weight basis, with a strong amino acid profile that matches fish nutritional requirements well. Their high moisture content (around 70% fresh weight) means they don’t absorb water and swell in the gut the way some dry foods can.

For koi specifically: Calci Worms are a popular summer treat. The larvae float briefly before sinking, triggering surface feeding behaviour that is excellent for watching and hand-taming koi. Feed sparingly — a tablespoon or two per fish per feeding session, 2–3 times per week at most as a supplement to a complete koi pellet diet.

For aquarium fish: Drop a small number into the tank and observe. Most predatory species respond immediately. For surface feeders, drop directly on the water surface. For mid-water and bottom feeders, larvae will sink gradually and be taken as they fall. Avoid overfeeding — uneaten larvae will die and foul the water if left for more than a few hours.