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fish harasment

3K views 20 replies 6 participants last post by  Christople 
#1 · (Edited)
i hav e a 20 gallon tank with 4 danios and a cory catfish. the danios are very agressive and nip at the cory all day long. how can i keep the pesky danios of the cory? they will kill him eventually if it continues.:cry:
 
#6 ·
I have always had problems with danios turning tanks into a chaotic mess. It always seems like I get one who is a complete jerk. I have now moved every danio I own to my cold water tank with my feeder crayfish and all my tanks are much more peaceful. Personally I think danios are just poor companions for tropical fish, they are actually a cold water minnow and I think the warm water just makes them crazy.
 
#8 ·
I have never kept gouramis, I am more of an african cichlid guy. I don't actually know why danios get so crazy, I just have theories. My suggestion would be to get a few more corys to bring your group total to 5-7. They will shoal together and feel more secure that way.
 
#10 ·
I have hard water so Africans are a much better match for my water. They also have some really interesting behaviors if you like to watch your tank. Once you really get into them their are so many species and so many different looks as well. I can honestly watch my shell dweller tank for hours and be entertained the whole time.

I am also really into the more vibrant types of plecos. I currently have a group of Hypancistrus contradens growing out that I will try to breed, but I have to get 5 gallons of RO from my LFS each week just to ensure the tank water perimeters stay in line with what the fish prefer. Any more soft water fish and I would be in the market for an RO/DI unit, which I don't really want to do. I've also kept danios, pirahna, and a few other randoms.
 
#11 ·
You didn't say which species of danio, but all of them are shoaling fish, meaning they need a group. While six is usually considered minimum number, more is better.

Shoaling fish occur in large numbers in their habitat. This affords protection, but also they frequently (depending upon species) have a social structure within the groups. A recent (and the first) scientific study has proven that when shoaling fish are kept in smaller groups, less than 5-6, they frequently become more aggressive. Smaller tanks also cause this. Part of the reason is stress; not having the fish they expect around them and having too little space is stressful, and this leads to aggression (even in otherwise peaceful species) and a weakened immune system. I suspect this is a circle in effect.

If you check the species in our profiles section [second tab from the left in the blue bar at the top] there is info on minimum tank sizes [for only the fish species, additional fish in the tank may require more space], minimum numbers where applicable, and suitable companions. Also water parameters including temperature are given, and as someone mentioned earlier, fish kep at inappropriate temperatures can also be stressed and...here we go again.

And corys are shoaling fish, and should never be less than 3 in an aquarium, preferably 5.

Byron.
 
#15 ·
In the wild, all species of Corydoras live in shoals of hundreds of fish. Sometimes two or more species will be together, but they remain within their respective species. On his own, a cory is highly stressed; looks are deceptive, after all, on his own, he has no choice, but inside he knows he is in a very un-natural situation, and that causes stress. Corys are highly social, varying somewhat from species to species, but this is part of their instinct and must be provided for.

Here's a link to a video of corys in the Amazon that will illustrate what I'm saying.
 
#18 ·
He won't kick the bucket overnight, or in a few weeks, but he is, to use the best word I can think of, somewhat unhappy--and that means stressed. And we want to better that. Next time you're in the fish store, get 2 more; as I mentioned, three seems to work. I have several cory species in my 90g and 115g, and it is interesting how some species almost never leave eath other, and others will. But they like to have their own near them. My panda corys are always together, and do they ever interact--nudging and tickling each other with their sensitive barbels constantly as they swim around.
 
#19 ·
yeah he does seem stressed. he is swimmin all over the tank and runninng into all he other tankmates. im planning on going to he petshop this weekend to get 2 more cories. my only concern is the food supply. im only feeding flake food. should i ad in brine shrimp or any other supplemental food?
 
#20 ·
You must get some sinking foods for bottom fish; they cannot survive on scraps of flakes that may reach the bottom.

There are many good sinking foods, whether pellet, sticks, tablets or disks. Corys are carnivores so shrimp pellets are good. It is always good to have 2 or 3 different kinds, to ensure a well balanced nutrition; also, some are more palatable than others. Mine really like Nutrafin's basic tablet food. I also include one algae or spirulina-based tablet, to ensure they get their "veggies."

Frozen bloodworms are good, but not in excess; once or twice a week as a treat will suffice. And the other fish will love these too, so make sure some get down to the cory(s).
 
#21 ·
I like the cichlid family period
 
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