The colony hunts and feeds through the cooperation of two types of zooid: gastrozooids and tentacle-bearing zooids. The tentacle-bearing zooids (also known as tentacular palpons or dactylozooids) are equipped with tentacles, which are typically about in length but can reach over . Each tentacle bears tiny, coiled, thread-like structures called nematocysts. Nematocysts trigger and inject venom on contact, stinging, paralyzing, and killing adult or larval squids and fishes. Large groups of Portuguese man o' war, sometimes over 1,000 individuals, may deplete fisheries. Contraction of tentacles drags the prey upward, into range of the gastrozooids, the digestive zooids. The gastrozooids surround and digest the food by secreting enzymes.