Select options Glass Catfish (Kryptopterus bicirrhis) $7.99 The Glass Catfish or Ghost Glass Cat has been popular in the aquarium trade for decades due to its unique, almost completely transparent body and active behavior. In the wild, they inhabit a variety of freshwater habitats in Southeast Asia, from clear water streams to quiet swampy areas, where they are typically found in large shoals. A peaceful, schooling fish, they are relatively hardy in the aquarium but prefer slightly soft water and excellent water quality. They should be kept in groups of at least 5 fish so they can form a school. Fast moving or nippy tankmates should be avoided as they can stress out the more peaceful Glass Catfish.