Mysterious Death to My School of Roseline Sharks

[fisheatfish]

Had ten 4 inch roseline sharks in my 150 gallon discus community tank along with clown loaches, cardinal tetras & plecos.

Decided to move the setup to a different part of the house so I had to empty the tank. Everything went into a 55 gallon drum with a heater & air stone. All the livestock, live plants, drift woods & tank water went into the container. While cleaning the filters, I allowed my 11 yr old son to catch all the livestock. During the move, I noticed one roseline shark floating...dead...slowly, one by one died. Oddly, the smallest one was the last to go. All other livestock have been transferred into the tank and are doing well.

My only explanation for their death is the stress that was put upon them during the move. They're fast and my son had an ordeal chasing them into the net. I'm an experienced aquarist...at least I thought I was. Been searching for an answer for their death. Looking for some help if anyone has any ideas so this doesn't happen in the future. The school of roseline sharks create movements in the tank and without them, my discus tank seem very boring so I'll be replacing them soon. Thanks.

 

[celebrist]

So you watched them keel over and croak right in front of you? That must have been brutally demoralizing, sorry for your loss those are really nice fish. How long had they been in the tank compared to the rest?

 

[krichardson]

Sounds like the sharks were done in by the chasing around with the net and being moved.

 

[fisheatfish]

So you watched them keel over and croak right in front of you? That must have been brutally demoralizing, sorry for your loss those are really nice fish. How long had they been in the tank compared to the rest?

Ya...it happened right in front of me. Never felt so helpless as I watched them take their last breath. I even attempted to revive one of them by blowing into its mouth and pumping its mid section. This process actually worked on a koi fish that jumped out of my pond.

The first one died after 20 minutes in the holding container...the last one died after about 2 hrs.

 

[fisheatfish]

Sounds like the sharks were done in by the chasing around with the net and being moved.

I've transferred them before from another tank without any problems. My son had trouble with 2 or 3 that were really fast but for all of them to die the same way is mind boggling. Trying to figure out what to do or not to do next time. I've done this so many times before with many other fishes. One have even flopped on the tile floor in the past during a move and another got tangled up around its gills with thread I used to tie down some moss onto a piece of driftwood...they survived those stressful events but not this move.

 

[celebrist]

I don't think it was the netting, there had to have been something in the water. Have you used the 55 gallon drum before? It sounds like you had them a while and they have handled other moves okay

 

[Drstrangelove]

http://www.iucnredlist.org/details/169662/0

Is this the fish you are referring to? They seem to be endangered, although perhaps this link is referring to a different species or is in error.

Regardless, I wonder if your oxygen levels were too low:

1) chasing fish depletes oxygen reserves
2) plants in a drum with inadequate light will begin consuming oxygen
3) the smallest fish will die last
4) different species have different oxygen requirements, so the species with the largest requirement might die while the others survive
5) no other obvious causes of death and the fish were fine prior to the move
6) stress might increase metabolism which might induce even higher oxygen needs
7) rosaline shark are normally in very clean, rapid moving waters which implies high oxygen content

If the sharks or other fish were at the surface gulping air, it might be a clue as well.

Just some thoughts to consider. Sorry you lost them as they are very cure fish and seem well suited to their tank mates.

 

[fisheatfish]

I don't think it was the netting, there had to have been something in the water. Have you used the 55 gallon drum before? It sounds like you had them a while and they have handled other moves okay

The 55 gallon drums are food grade containers. I use them to age water, store RO water & to filter my pond. I used the same water that came from the tank and threw in an air stone for oxygen. I've done this in the past and even threw in a heater when I kept fishes in there overnight.

 

[fisheatfish]

http://www.iucnredlist.org/details/169662/0

Is this the fish you are referring to? They seem to be endangered, although perhaps this link is referring to a different species or is in error.

Regardless, I wonder if your oxygen levels were too low:

1) chasing fish depletes oxygen reserves
2) plants in a drum with inadequate light will begin consuming oxygen
3) the smallest fish will die last
4) different species have different oxygen requirements, so the species with the largest requirement might die while the others survive
5) no other obvious causes of death and the fish were fine prior to the move
6) stress might increase metabolism which might induce even higher oxygen needs
7) rosaline shark are normally in very clean, rapid moving waters which implies high oxygen content

If the sharks or other fish were at the surface gulping air, it might be a clue as well.

Just some thoughts to consider. Sorry you lost them as they are very cure fish and seem well suited to their tank mates.

Yes...this is the fish I lost. They're easy to care for and aren't picky eaters but appears to be very difficult to breed in captivity, which explains their endangered status. Low oxygen in the water makes a lot of sense and these fish being so active & move with lightning speed, they may very well have depleted much of their oxygen for them to go so quickly. You're absolutely right about different species requiring different oxygen levels...makes a lot of sense for slow movers like my discus to require less oxygen. Thanks for your help. This will definitely be a precaution I will consider in the future.

 

[celebrist]

Still, you had an airstone in there, that is a mystery for sure, how long were they in the drum and how long did it take your son to catch them?