How to Kill Mantis Shrimp

Mantis shrimp come in a variety of colors and may seem like a decorative addition to your saltwater aquarium. However, these crustaceans -- which can sometimes hitchhike on rocks into your waters -- have strong front appendages designed for smashing other crustaceans or spearing fish. With these weapons, the shrimp can kill your tank's inhabitants, destroy your underwater habitat and even hurt you. If you need to rid your aquarium of a mantis shrimp, first capture the creature in a trap before humanely killing the creature.

Things You'll Need

  • Plastic soda bottle
  • Knife
  • Bait
  • Freezer
  • Anesthetics
Show More

Instructions

    • 1

      Build a trap to catch the mantis shrimp, starting with a cleaned 16-ounce plastic soda bottle. Remove the lid. Cut the bottle across the top at its widest point with a knife. Bait the trap by placing shrimp pellets, fish food or brine shrimp in the bottom of the bottle. Invert the original top part of the bottle and place it in the body of the container. This should create a funnel toward the bait. Do not glue the bottle pieces together.

    • 2

      Fill the trap with water from the aquarium. Place it in the tank on its side near the area where the mantis shrimp lives. The mantis shrimp will be drawn into the bottle to eat the bait, and then won't be able to get out. Check the trap in the morning, because mantis shrimp are nocturnal and will hunt at night.

    • 3

      Keep the mantis shrimp in the trap and remove the animal and the container from the aquarium.

    • 4

      Place the mantis shrimp and the bottle trap in a freezer. Leave it in the freezer for at least one hour. Mantis shrimp come from warm waters, so placing it in a cold environment will lower its metabolism and kill the crustacean.

    • 5

      Add an anesthetic to the bottle trap's water if a freezer is not available. You can use Tricaine Methanesulfonate (TMS), which can be purchased over the counter at pet stores, by placing it in the water at double the regular dosage recommended to anesthetize a fish. Or you can get a prescription for Benzocaine Hydrochloride from a veterinarian and follow the recommended directions to kill the crustacean. Never put these anesthetics in the main aquarium water, as they could harm the rest of the inhabitants.