I want fish that are very active

Although they may take a while to settle into their new tank, Cherry Barbs are the perfect freshwater fish for a home aquarium for all of the reasons listed above. They can tolerate big changes in water parameters, they are friendly, they only grow to around 2 inches long and in general, they are an easy fish to take care of. As one of the most endangered species of fish in the wild, the Cherry Barb is still a favourite within the fishkeeping community, thanks to it’s bright, eye catching colours, and it’s entertainment value. They are a very active fish, and once they become accustomed to their new surroundings, they will be very active and fun to watch.

Freshwater fish compatibility chart and characteristics of different types of fish.

Tropical Freshwater Community Fish | Freshwater Tropical Fish Species: Harlequin Rasboras 2 inches; active schooling fish; may nip fins of slower moving tank mates if not provided enough space; prefer planted tanks. Tags: aquarium, tropical, pet, fish.h

small for these schooling fish they are not as active as I'd like

Overview of active cesium contamination of freshwater fish in Fukushima and Eastern Japan lake kutubu rainbowfish - beautiful & active freshwater fish with distinct personalities, but they get pretty big, so don't even think of getting any unless you have a tank of 40 gallons or more; they also MUST live in a group of their own species to feel comfortable--the more comfortable/less stressed they are, the more healthy, more confident (therefore more interesting to watch) and longer-lived they will be

thankfully the school library ..

This paper focuses on an overview of radioactive cesium 137 (quasi-Cs137 included Cs134) contamination of freshwater fish in Fukushima and eastern Japan based on the data published by the Fisheries Agency of the Japanese Government in 2011. In the area north and west of the Fukushima Nuclear plant, freshwater fish have been highly contaminated. For example, the mean of active cesium (quasi-Cs137) contamination of Ayu (Plecoglossus altivelis) is 2,657 Bq/kg at Mano River, 20–40 km north-west from the plant. Bioaccumulation is observed in the Agano river basin in Aizu sub-region, 70–150 km west from the plant. The active cesium (quasi-Cs137) contamination of carnivorous Salmondae is around 2 times higher than herbivorous Ayu. The extent of active cesium (quasi-Cs137) contamination of Ayu is observed in the entire eastern Japan. The some level of the contamination is recognized even in Shizuoka prefecture, 400 km south-west from the plant.

Another active fish is a Rummy nose Tetra.