Sisorid catfish in general are very sensitive creatures i.e they react to the slightest of changes in their surroundings and this makes them a good pollution indicator in nature. If a stretch of river harbours these creatures that means the water there at that particular stretch is healthy. I mention "stretch" because a river passes through several different terrains and areas like forest, rural and urban. In urban areas the rivers are touted to be the most polluted.
All major Indian rivers harbour Sisorid catfishes through multiple genera, but these catfishes only occur in the parts where the river is the most healthy.
Gagata can be considered as one of the most sensitive ones among Sisorids, with the degree of sensitivity towards water parameters varying for each genus differently.
In home acquaria to maintain Gagata for longterm requires utmost skill and patience as one will learn through keeping these gentle creatures that how delicate is the balance of nature and we are far from understanding it properly. Even the slightest of changes in water quality leads to instant death as has happened with me multiple times. - Abhisek_Mishra
