Species like the chili rasbora are one of the several schooling fish that can thrive in a very 5-gallon aquarium. Therefore, some fish species at the moment are categorised as severely endangered and have become far more scarce in the wild. Pretty much all the rare species on this listing https://aquariumtankrental.wordpress.com/2024/10/18/how-to-maintain-a-2-feet-aquarium-bigger-fish-tanks/