something strange in my tank

Patticakes · 04/27/2006, 06:09 AM

My tank is only about 3 months old. I have the following in it so far: 1 clownfish, 2 damsel fish, 1 skunk cleaner shrimp, 1 purple tip anenome, live rock, 3 different plants, hermit crabs, snails. I have seen a couple of strange looking creatures one time and never saw them again. One of them looked like a loach. It had its head sticking out of the coral and when it saw me, it sank back into the coral never to be seen again. It was yellow and red. The other thing looked like a strange shrimp with very long tentacles. It was clear in color and I am surprised that I saw it at all. Now to my question: I just bought a power head. I decided to move it to a different position in my tank, but I didn't unplug it. Well, I accidentally pointed it toward the bottom for a couple of seconds. It blew something off the bottom that I hadn't seen before. It looked like an egg sack or cocoon. It was floating on the top and I could tell something live was inside it. Something inside seemed to be moving around. I caught it as gently as I could with some long handled feeder tongs I have and put it behind a big rock, hoping I hadn't hurt it. This morning, the sack was floating on top, empty. Any ideas what it might be????

springer275 · 04/27/2006, 07:35 AM

Maybe a crab deposited some eggs. Any pics?
If it was a single egg, shaped kinda like a square, and you could see it moving inside, then it may have been a type of shark. Did it come with the live sand or rock?

XeniaMania · 04/27/2006, 07:44 AM

The loach looking thing could be a Eunice worm which does have 5 antennaes and it anchors itself to the rock and when seen, it retracts quickly. Not sure about the shrimp. The cocoon most likely is a tunicate.
opps...nvm..didn't see the "live" part regarding cocoon..my bad..

Randall_James · 04/27/2006, 07:56 AM

amphipods will cast a cocoon of substrate around themselves as they brood eggs. They stay inside this tube pumping water with their backhalf until the brood hatches. I see them pretty regularly using the tank wall for 1 side of this cocoon.

Patticakes · 04/27/2006, 08:22 AM

This cocoon looking thing was about 1 1/2 " long. I hope I didn't kill whatever it was.

aynoT79 · 04/27/2006, 08:27 AM

If you have live rock in your tank, then you will see all different things you have never seen before.. My life rock has slug looking things and all different kinds of worms and things comming out of it.. Live rock carries alot of things, nothing should harm your tank or your fish i wouldnt worry about it.. thats a benifit of having live rock you never know what your gonna get.. I have live rock with corals of some kind comming off of it...

Sk8r · 04/27/2006, 10:07 AM

Those creatures help break fish poo down into a size particle that sps corals can eat. A few of them can be baneful, but generally not. Worms sting if touched, not badly, and they're your good friends. Eunice worms I'm less enthusiastic about, but by your description it could have been an ordinary bristleworm, which is good. Shining a flashlight on your sand at night may turn up all sorts of things.

04/27/2006, 06:09 AM	#1
Patticakes Registered Member Join Date: Aug 2003 Location: Mississippi Posts: 54	something strange in my tank My tank is only about 3 months old. I have the following in it so far: 1 clownfish, 2 damsel fish, 1 skunk cleaner shrimp, 1 purple tip anenome, live rock, 3 different plants, hermit crabs, snails. I have seen a couple of strange looking creatures one time and never saw them again. One of them looked like a loach. It had its head sticking out of the coral and when it saw me, it sank back into the coral never to be seen again. It was yellow and red. The other thing looked like a strange shrimp with very long tentacles. It was clear in color and I am surprised that I saw it at all. Now to my question: I just bought a power head. I decided to move it to a different position in my tank, but I didn't unplug it. Well, I accidentally pointed it toward the bottom for a couple of seconds. It blew something off the bottom that I hadn't seen before. It looked like an egg sack or cocoon. It was floating on the top and I could tell something live was inside it. Something inside seemed to be moving around. I caught it as gently as I could with some long handled feeder tongs I have and put it behind a big rock, hoping I hadn't hurt it. This morning, the sack was floating on top, empty. Any ideas what it might be????

04/27/2006, 07:35 AM	#2
springer275 Registered Member Join Date: Nov 2003 Location: Ohio Posts: 53	Maybe a crab deposited some eggs. Any pics? If it was a single egg, shaped kinda like a square, and you could see it moving inside, then it may have been a type of shark. Did it come with the live sand or rock? __________________ Springer technology is our friend Current Tank Info: Reef

04/27/2006, 07:44 AM	#3
XeniaMania Registered Member Join Date: Feb 2006 Location: Orange, CA Posts: 1,627	The loach looking thing could be a Eunice worm which does have 5 antennaes and it anchors itself to the rock and when seen, it retracts quickly. Not sure about the shrimp. The cocoon most likely is a tunicate. opps...nvm..didn't see the "live" part regarding cocoon..my bad.. Last edited by XeniaMania; 04/27/2006 at 08:09 AM.

04/27/2006, 07:56 AM	#4
Randall_James Premium Member Join Date: Feb 2005 Posts: 6,727	amphipods will cast a cocoon of substrate around themselves as they brood eggs. They stay inside this tube pumping water with their backhalf until the brood hatches. I see them pretty regularly using the tank wall for 1 side of this cocoon. __________________ "It's a dog eat dog world and I feel like I am wearing milkbone underwear"

04/27/2006, 08:27 AM	#6
aynoT79 Registered Member Join Date: Apr 2006 Location: Kinston, NC - USA Posts: 51	If you have live rock in your tank, then you will see all different things you have never seen before.. My life rock has slug looking things and all different kinds of worms and things comming out of it.. Live rock carries alot of things, nothing should harm your tank or your fish i wouldnt worry about it.. thats a benifit of having live rock you never know what your gonna get.. I have live rock with corals of some kind comming off of it... __________________ (`'·.¸(`'·.¸¤¸.·'´)¸.·'´) «´¨`·..¤ToNyA¤..·´¨`» (¸.·'´(¸.·'´¤`'·.¸)`'·.¸) Current Tank Info: Beautiful 55 Gallon Salt

04/27/2006, 08:22 AM	#5
Patticakes Registered Member Join Date: Aug 2003 Location: Mississippi Posts: 54	This cocoon looking thing was about 1 1/2 " long. I hope I didn't kill whatever it was.

04/27/2006, 10:07 AM	#7
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	Those creatures help break fish poo down into a size particle that sps corals can eat. A few of them can be baneful, but generally not. Worms sting if touched, not badly, and they're your good friends. Eunice worms I'm less enthusiastic about, but by your description it could have been an ordinary bristleworm, which is good. Shining a flashlight on your sand at night may turn up all sorts of things. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.