how big

[Rayne]

what can anybody tell me about columbian sharks? how big do they grow? are they aggressive? how big tank do they need? and is there anyfish you can't keep them with?

 

[Hey You]

They will get to about 12". When they mature. They need to be in a salt water environment.

 

[The-Wolf]

Order: Siluriformes
Suborder: Siluroidei
Family: Ariidae
Genera: Arius
Species: seemani
size: 12-14 + inches (30-35cm)
tank: 48 inches minimum for young
strata: Lower to middle
pH: 6.8 to 8.0
Hardness: medium hard to hard, 8-30 dH
temperature: 75ºF to 80ºF (25-27°C)
Although sold as a freshwater catfish, the Colombian shark is best suited for the Brackish aquarium. Like most Brackish species, the young are more tolerant of water conditions than the adults. The water should have some sea salt added and measure a salinity of 1.005 to 1.015.
They are a predatory fish and should be housed with species that cannot be eaten. Feeding is not a problem as they will accept all types of prepared food. Sinking pellets, live insects, earthworms and small fish are some of its favorites. They have a voracious appetite and if not well fed will harass the other tank mates.
HTH.