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Injuries in Captivity

May 31, 2006
Ok, so my octopus still isn't eating. he wasn't even interested in his crab today :sad: I did notice that the tip of one of his arms was white, however, suggesting that there was some skin trauma to the very tip. He may have stuck the tip of his arm up one of the holes in my outflow diffuser. Does anyone know if that might affect his behavior? I've heard that octos injured in captivity don't have a high survival rate due to infection, so I'm hoping it's not as seroius as that, but I can't help but wonder with his recent aversion to food.
Water quality is still good? I have had octos in the past that have injured themselves but the regrowth rate has been amazing and they never stopped eating because of the injury. Only reason any of mine ever went off feed was either ammonia was sneaking up or old age/eggs.

Yeah, I'm concerned it might be old age. I e-mailed the man I ordered the octos from to see if I could get an age estimate. The water quality is as good as its ever been, and ammonia is being processed by the bio filter, so I don't think that's it. I mean, it's not zero, but it's close, and I do daily water changes. It has been higher in the past and they were eating no problem, so I'm disinclined to think that's the problem.
Yeah, Octos are very sensitive to Ammonia. I would keep doing the water changes every day, or it will get worse. But the question is, why is there ammonia? Is your tank even cycled?
My tank has been cycling for a while now (a month or so), and the bio filter seems to be working (as in, Ammonia has dropped to around .05 - .1). However, because of space contraints at the school, most of the cycling has had to be done with the animals already in the tank. I don't know if that has something to do with it. I know ammonia should be zero, but with daily water changes they should be fine. When I first got them in smaller tanks the ammonia was way higher, even with daily water changes, and they were behaving and eating regularly...
A month isn't really long enough to properly cycle the tank (3 months at least). How can you cycle it with the animals in it?????? The amount of waste an octi produces is phenomenal, the tank has to be totally stable BEFORE you add the octopus or the filtration just won't cope. How big is the tank (I can't remember if you've mentioned this anywhere:confused: ) but if it's less than 50 G it's too small and is very likely to never get stable enough for an octopus. Also cover that diffuser with some mesh! Octopus stick their arms into ANYTHING!

Can you get hold of a filter sponge (or other filter media) or some water from a stable, totally cycled tank? If so add the sponge to your filters and/or water to your system that may speed up and finish the cycling in your tank.


I have put water from an established tank into the system twice since I got it up and running. Unfortuneately, due to time and spacing constraints, I had to get the animals in there before the tanks were fully cycled. The biofilter does seem to be working in some capacity as it is. Do you think it would help to add additional water from the established tank? I don't really ahve a choice in keeping the octos anywhere else. The tank is a 40 gallon, I'm pretty sure. It's the biggest we had. I have 2 40 gallons hooked up to a sump, each on separate pumps. The bio filter is in the sump, and I have a UV filter as well. each tank has their own up to 50gal fileter with activated carbon and filter sponge. The ammonia did go down after a bit so the biofilter seems to be working in some capacity.

I talked with some people here at the school, and they said they didn't think it was the ammonia. The change wasn't really gradual either. They were feeding fine, then all of a sudden there was an appetite drop the next day...then all of a sudden a while later one would stop eating and soon afterwards die. The one that died didn't even want to attack a crab in the end. I was told ammonia would be a less gradual, more visible change with a quick reaction or death as the case may be. This has been over a period of 3-4 months.
Ammonia and nitrite should be zero, period.

Most aquarists that lose stock because of ammonia or nitrite have a completely cycled, healthy system with neither nutrient present (or more accurately it is processed as soon as it becomes present); then for some reason such as an equipment failure or a dead animal ultimately leads to more nutrients in the system that can be processed quickly. There's way too much ammonia in the tank and everything dies suddenly. Imagine smoking a thousand cigarettes in an hour. If experienced aquarists are telling you that your problems don't sound like ammonia, this is why.

Your situation is completely different because your system never fully cycled. Your animals have been breathing smaller amounts of ammonia for months, and as such we wouldn't expect to see sudden and random death, but rather chronic symptoms. A pack of cigarettes a day doesn't kill you on the first day.
Cephs are incredibly sensitive to water quality issues. While fish etc may deal with some ammonia (although this is far from ideal!) Ammonia and nitrate/nitrite build up in the tissues and digestive gland in cephs is fatal. It's unfortunate that you have time and space constraints but this makes octopus (or any other ceph) a very unsuitable species for your study.....they simply will not tolerate a tank that is not completely cycled. 40 G is a bit small, 50G is really the minimum size for an octi. Especially if the tank isn't cycled.


:sad: Can't stress it enough, octopuses do not tolerate any level of ammonia. Tanks need to cycled for at least 3 months till the cycle is stable. Adding an animal before the tank is "mature" only leads to the animals suffering and eventual demise. I remember Inklet, I had an equipment failure, and finally realized the reason he was frantically trying to climb out of the tank was because his skin was irritated from a reading of .50 ammonia. Even adding culture from an existing tank does not speed up the process.