# black fin sharks



## wapaksentra (Apr 25, 2006)

ok had 2 die on me in a week i dont know why this happened. Other than i might of introduced them into the tank to soon with the other 2 fish i have (pictus catfish). i noticed though they did not eat what the pet store recommended for food Algae wafers and tropical flake food. i dont understand what happened any ideas?


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## Guest (Apr 29, 2006)

Do you mean the black fin shark also known as a Columbian Shark? If so, these guys like a little salt in their water.

What size tank did you have them in? Are the pictus cats the only other inhabitants? Do you know the water parameters (nitrite, nitrate, ammonia, pH)?

We need a little more info to help you.

About the food: Sharks are usually bottom fish, so they probably won't come to the surface to eat flakes. And they need more to eat than the algae wafers. Sinking shrimp pellets would have been a better choice. Also, some frozen or live bloodworms would have been something they couldn't turn down.


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## wapaksentra (Apr 25, 2006)

well its a 10 gallon tank, temperature is at 76-78 i dont know the ph or any of that the pictus are the only other inhabitants, ii dont know the ammonia nitrite stuff. yes i mean the columbian shark


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## heatherhoge (Nov 13, 2005)

Yes these fish will die with out marin salt using low salinity to start. I had the same problem when i first started with this fish. They will get bumbs on their skin due to not enough salt as a begining sign they need it. If you put salt in the tank and if they are deprived they will rush to it and start eating it. That is good. They are a brakish fish with flexing salinity. Store sell them as freshwater cuz they are born in fresh but most employees of store don't know much they seem to be very general and don't tell people they will need brackish. This fish thrives off frozen as well as shrimp pellets. They will not touch alge. I would mix up pellets and frozen not feeding the same all the time. These fish get big. I have 6 in a 125 gal all about 8" and still growing. Mine are about 2years old. Just to give you and idea of their growth rate.


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## Guest (May 2, 2006)

> I have 6 in a 125 gal all about 8" and still growing. Mine are about 2years old. Just to give you and idea of their growth rate.


Yes, so I wouldn't be keeping them in a 10g tank. It may be another reason they died. They get too big. As do the pictus cats, for a 10g. I would upgrade pretty soon. A 20g tank is the minimum for pictus cats. If you are planning to get more sharks...then I would say around a 75g would be minimum. Bigger is better though...knowing how fast they grow.

Knowing the ammonia and nitrite is good. Its a good idea to monitor those two parameters. If the fish produce enough waste to get the ammonia too high, it could kill them. I would be checking that, so that I wouldn't waste my money again (by having the fish die).
A good test kit isn't all that expensive. Aquarium Pharmaceuticals makes a Master kit that has ammonia, nitrite, nitrate, and pH....all the basics.


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