Is it possible that we have a mantis shrimp in our Salt Water Tank?

Question

We have a 55 gallon aquarium with a 4 in. live sand bed. We put the live sand in with saltwater and let it run for a month before adding fish. We don't have any live rock, but within three days our 3 yellowtailed blue damsels are found dead in the same spot with what appears to be nipped fins and the body picked at. When purchased and acclimated the little fish appeared fine, I've tested the levels almost everyday since we set up our tank. Amonia has been 0, pH between 8.2 and 8.4 and Nitrate and Nitrite 0. Like I said 3 fish, one died every day? What could it be?

Thanks for the help in advance! :)

Answer 1

If there's no live rock or any other place for the mantis shrimp to hide, then you probably don't have mantis shrimp.

However, like the first answerer, you could have bristle worms. They attack at night, and are very dangerous. They have a pinkish colored body and bristles all along the side of its body. The bristles are toxic, and its jaws are very strong. They reproduce very rapidly, and may even take over your tank in a matter of weeks.

DO NOT touch the bristleworm with your hands. Their bristles will get stuck in your hand and will be very itchy.

There are two ways to get rid of bristleworms. The first way is to use a trap: http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+18180+3960&pcatid=3960
The second way is to purchase a Coral Banded Shrimp. These Shrimp will eat bristleworms, and will also clean the bottom of your tank for you. Keep in mind that they can grow to 4 inches. It prefers a cave to hide in during the day, as they are nocturnal.

E-mail me for any questions!

ZTM

Answer 2

If there is a Bristle worm in the sand, it would come out to eat when the lights are off.
They are vivid pink, really pretty with bristly appendages but they eat all the invertebrates if not removed.
If you have no places for the Mantis shrimp to hide, like shells or rock formations, I doubt that you have any. They are really neat looking but they don't go after the fish, they go after inverts living in shells.
They are also most active at night.
The fish may have been ill when you purchased them, and died over several days.
Sounds like something ate at them. You will definitely know if it's a Mantis Shrimp because they are noisy breaking up coral and shells.
Purchase a Bristle worm trap to capture them. They should be available anywhere that sells Marine fish. Load the trap with a small amount of freeze dried brine shrimp. Remove all the air from the trap before placing back in the tank.

Answer 3

1.No you dont have a mantis shrimp.
2.Bristle worms are not harmfull and will not kill your fish.I have heaps,big and small.They clean up left over food and stuff in your tank so perform a good duty.I dout you have any because they normally come in on live rock.
Take a sample of your water to your local fish shop and get them to test it just to be sure.Are you keeping your salt levels right and your water temprature correct?

Answer 4

yes,of the salt water variety..