We have 5 columbian sharks.If kept in a group of at least 4,then they feel better in themselves and swim around a lot more rather than hiding away.
The scientific name is arius seemanii, commonly known as columbian sharks,white tipped sharks, or black finned sharks.
They eat mainly chopped cocckle mussel and prawn,chopped very very small,and also love bloodworms.
Want brackish from about 4",increasing with size.We currently have ours in with 8 dragon/violet gobies which are a good tankmate. The brackish water should be increased to full marine as they grow.Hope this helps.