Separate species schooling together

[El chapo]

Is it common for different species of fish to school together

 

[SeaAngel]

If they are close, such as neon tetras and green neon they will schoal together.

 

[El chapo]

If they are close, such as neon tetras and green neon they will schoal together.

I was wondering because my irredessant shark and my silver dollar are schooling together and I'm not sure if that is normal

 

[Byron]

I was wondering because my irredessant shark and my silver dollar are schooling together and I'm not sure if that is normal

No it is not "normal" and more likely an aggressive behaviour. Or stress.

 

[Essjay]

Do you have just one shark and one silver dollar? Both of these are shoaling fish and need a group of the same kind. If there is just one of each, this will cause the stress - leading to aggressive behaviour - that Byron mentioned.


How big is your tank? Iridescent sharks are huge fish capable of growing to over 36 inches (90 cm) and needing a tank at least 15 x 6 x 6 feet (450 x 180 x 180 cm). They are not suitable for home aquariums.
And while silver dollars aren't as big they still need a tank at least 72 x 15 x 15 inches (180 x 37.5 x 37.5 cm)

 

[El chapo]

Do you have just one shark and one silver dollar? Both of these are shoaling fish and need a group of the same kind. If there is just one of each, this will cause the stress - leading to aggressive behaviour - that Byron mentioned.


How big is your tank? Iridescent sharks are huge fish capable of growing to over 36 inches (90 cm) and needing a tank at least 15 x 6 x 6 feet (450 x 180 x 180 cm). They are not suitable for home aquariums.
And while silver dollars aren't as big they still need a tank at least 72 x 15 x 15 inches (180 x 37.5 x 37.5 cm)

They are both alone in a 55 gallon

 

[Essjay]

You need to rehome the shark. This species needs to be in a group in a public aquarium. They should not be sold in the trade to home fish keepers except possibly the very few who have a tank the size of a swimming pool. Your shark will grow to over 3 feet long.
http://www.seriouslyfish.com/species/pangasionodon-hypophthalmus/

And unless your tank is at least 6 feet long, you need to rehome the silver dollar as well, and get fish that are suitable for your tank, both it's size and the hardness of your water.
If your tank is 6 feet long, get at least another 5 silver dollars.
http://www.seriouslyfish.com/species/metynnis-hypsauchen/


It is cruel to keep fish in a tank that is too small, and it is cruel to keep shoaling fish on their own - they need at least 6 of the same species or better, more than 6.

 

[El chapo]

You need to rehome the shark. This species needs to be in a group in a public aquarium. They should not be sold in the trade to home fish keepers except possibly the very few who have a tank the size of a swimming pool. Your shark will grow to over 3 feet long.
http://www.seriouslyfish.com/species/pangasionodon-hypophthalmus/

And unless your tank is at least 6 feet long, you need to rehome the silver dollar as well, and get fish that are suitable for your tank, both it's size and the hardness of your water.
If your tank is 6 feet long, get at least another 5 silver dollars.
http://www.seriouslyfish.com/species/metynnis-hypsauchen/


It is cruel to keep fish in a tank that is too small, and it is cruel to keep shoaling fish on their own - they need at least 6 of the same species or better, more than 6.

What do you mean by re-home

 

[Essjay]

For the shark - find someone who has a tank big enough for it; find a public aquarium that isn't already overstocked from people needing homes for giant fish; or worst of all take it back to the shop (where it will probably be sold to another unsuspecting customer)

Silver dollar - take it back to the shop, or find someone who already has a shoal and will take it in. Or get a bigger tank plus 5 more silver dollars.

 

[El chapo]

For the shark - find someone who has a tank big enough for it; find a public aquarium that isn't already overstocked from people needing homes for giant fish; or worst of all take it back to the shop (where it will probably be sold to another unsuspecting customer)

Silver dollar - take it back to the shop, or find someone who already has a shoal and will take it in. Or get a bigger tank plus 5 more silver dollars.

Can't take the shark back to where I got cause it's Walmart , the silver dollar came with the tank

 

[Discus-Tang]

Maybe go to a public (freshwater) aquarium like Sea Life?