PlanetCatfish.com

First off, hello to everyone! I've visited this site and its forums a couple times for information on how to care for my cory and my otos, and it has been very informative. It seems that you all really know your catfish!

Sadly, the impetus for my first post is the death of my Clown Pleco (L206), Craig. Craig was a happy and (seemingly to me) healthy fish, who had lived in my tank for about 5 weeks. He liked to hide under some driftwood during the day, but he always came out at night to swim around and look for food. I noticed over the last few days that my gold gourami seemed to be bothering him a little bit, but only because she wanted to peck at the spirulina tablets he had for food. I noticed yesterday that he was outside of his hiding spot at about noon, which is very unusual for him. It seemed strange but I didn't think anything of it. I left for class today and he was still outside his spot, even though the light had been on about an hour. When I came back I noticed that he was on his back, and looked very pale. Sadly enough it would seem that Craig died while I was in class.

I took a look at his body before the 'funeral' and there were some red splotches and general discoloration on his right side. However, I noticed no obvious signs of any fungal, bacterial or viral disease. There was no indication that his fins had been nipped, and definitely no open cuts or sores on his body. I'm very confused that he would die so suddenly, and I feel terrible that I couldn't have helped him to live a better life in my tank. I really like keeping plecos, but I don't feel like I should add a new one to my tank until I understand what happened to poor Craig. Any ideas what could have caused his death?

Requisite water info:
Temperature varies from 24 C at night to a peak of about 25 C during the day. The water pH is 6.4, but the water is also very hard. Not sure about specific KH or GH numbers. Testing right after Craig's death showed ammonia at 0, nitrite at 0 and nitrate at ~20ppm. I do weekly water changes of about 16%. The tank he was living in is 30 gallons, with fluorite as substrate. The filter I have is an emperor 280. There are a couple pieces of Jaspet, a piece of slate and a large log of driftwood in the middle of the tank. These furnishings are surrounded by a moderate amount of plants. There are 3 gouramies, an african butterly fish, a small group of serpae tetras (6), a leopard cory, 5 otos and 4 amano shrimp in the tank. The gold gourami was moved to another tank today. The tank was set up a little over two months ago. I added 3 otos yesterday, one day before Craig died. The gouramis and tetras eat bloodworms and flake food, while the shrimp and otos get occasional spirulina tablets.

Please help me understand what happened to Craig, and thanks in advance for your help.

It's always difficult to give the real causes for death of a fish even with pictures and information of water parameters, but your aquarium have only been running for 2 months so it may need some more time before it's in good balance. The second thought is that you bought the pleco only for 5 weeks ago and the fish maybe not was in perfect conditions from the beginning, red blotches and/or red markings on their fins is a sign of poisining, it could be ammonia or nitrite released from the substrate which affect fishes living at the bottom much faster then it does for fishes living in the water column. It's induvidual depending on many factors, one fish is not affected but another shows sign or die, this depends on how much or easy the blood uptake of ammonia or nitrite is in each fish. So, if a fish is not in the best condition it's most likely this fish is affecting first before others...thats why we cant say if it was ammonia or nitrite why is not the other fishes affected? which is the normal respons when trying to explain that a one fish died of ammonia/nitrite.

Sorry for your lost but dont give up on plecos, wait 1-2 months more until the aquarium should be in very good balance as long you make regular water changes and keep the bottom clean...then be fastidious when you choose the next pleco and only buy one that are in very good condition.

Janne

I did not realize that he would be more at risk for ammonia and nitrate poisoning! However now that you've explained it to me, it seems obvious that the mulm in the substrate at the bottom would lead to much higher concentrations of ammonia and nitrate. Thankfully, all my other fish seem fine. I will wait awhile longer before adding any fish to this tank, just to be sure my parameters stay stable. Thanks so much for helping me understand what was happening.