my blckmoore fish dies everytime i bring it but other gold fish are also living in that same aquarium.?

Question

i have one big tank of lenght 4 height 2 width 1 ft..and ihave 15 goldfsh in my aquarium of all size...and also tiger shark of small size..from many days but only my black moore dies everytime when i bring it. there is also small gold fish in comparison to black moore in the same tank..all gold fish never fights ..they all live peacefully ....

Answer 1

Two ideas occur to me-

1) Is the black moor the only "fancy" (double tailed) goldfish you have or the only one with telescope eyes? Goldfish have three "groups" - the commons, with a single tail (these are the fast guys), fancies with a double tail without vision impairment (they can see well all around them), and fancies with vision impairment (telescope eyes, bubble eyes, and celestial eyes which have part of their field of vision blocked). Because of body shape and vision impairment, the black moor may have a harder time getting enough food if the other can see it better or get to it faster.

2) Water quality/new fish syndrome - If your water quality isn't what it should be, fish will adjust somewhat to the conditions over time - especially if the change from good water is gradual. A new fish that's been in good water may not be able to adjust as quickly and die in the same water that others appear to be living in without any problems. A test kit, or taking a sample to a local pet store will let you know if this is a possibility.

Answer 2

Fish size: Determine the final length of the fish before purchasing it. This will help you in getting the right size of the tank with right water capacity for the fish.

Breed of fish: Check out if the fish is aggressive or amiable. Find out if he is comfortable solo or is social. Your tank should contain fish that mix well with each other. If not, the aggressive fish will kill him. Some fish guard their territory fiercely, and hence should be kept solo.

Food: Determine the staple food of your fish. Many prefer flakes but others go for freeze dried worms or any other food.
http://www.petskare.com/category/Tips-For-Choosing-Aquarium-Fish.html

Answer 3

It sounds like something in your tank is out of bounds for the blackmoore to stay alive, go get your water tested. Don't buy anymore fish till you do.

Make sure you get it tested for everything, PH, Amonia, nitrite, nitrate, copper, lead, etc.

You may find something shocking.