Copapods and amphipod die off?

[jrenoe1]

My 20L nano has had an amazing amphipod and copapod population, hundreds of the little buggers! But about a month ago they just disappeared. I also had some tube worm die off also. I now can't find one of them anywhere. Any ideas what might have happened?

I think my DOC got a little high, could that have done it? I was running with no skimmer and when I added one it knocked out a little algae bloom that was going on; that's why I think I had a DOC spike. No other problems or changes and all other life doing well.

I am thinking now that I have the DOC under control I should add a few pieces of good cured rock to re-populate?

Thanks for any ideas.

 

[JamesBryan]

I raise Gammarus amphipods. If dissolved oxygen lowers quickly (such as current being turned off) they will die off in great numbers if the colony was overpopulated artificially such as in a tank where they have few predators and have left over fish food to feed on. If dissolved oxygen content increases quickly they will be 'calm' for a short time and then resume normal activity. Tube worms also dieing off makes me think it was some other chemical reaction introduced.

 

[jrenoe1]

<a href=showthread.php?s=&postid=13339780#post13339780 target=_blank>Originally posted</a> by JamesBryan
I raise Gammarus amphipods. If dissolved oxygen lowers quickly (such as current being turned off) they will die off in great numbers if the colony was overpopulated artificially such as in a tank where they have few predators and have left over fish food to feed on. If dissolved oxygen content increases quickly they will be 'calm' for a short time and then resume normal activity. Tube worms also dieing off makes me think it was some other chemical reaction introduced.

Interesting points, thanks. I finally saw one tonight, but just one and have not seen anymore. What eats them? Only fish? I only have had one fish in this tank at a time.

 

[JamesBryan]

just about everyone eats them

just about everyone eats them

Everything eats them pretty much. They are omnivores so they eat whatever they can. It's a critter eat critter out there.

1lb gammarus amphipods (count them to about 100,000)
1/4 stick butter
pinch of salt
other spices as desired
throw it in a pan and fry till shirmp are good and dead

Yummy!

 

[dilbert_uk]

Shrimps like to eat them, too.

With two cleaner shrimps in my nano, I see only a few copepods and no amphipods at all.

I got one tank only to store Chaetomorpha at the moment. This tank has for obvious reasons a high ph swing from 8.2 to 8.8 and the remperature varies between 21°C to 32°C (70°F to 90°F) on some days because it's on the window sill.

Amphipods live happily in there and eat red slime. :lol:

 

[jrenoe1]

Still no bugs...

I need a fuge, that's what I think. When I set-up the 90 I am doing a combo fuge/sump.