My son is going to sell his fish and wanted me to photograph them, so I set up my camera and took a few photos of them. This is a 100 Gallon tank and theplecostomus' (The two separate fish in the photographs) are about 10 and 12 inches long. The two large fish are Pacu are about 13 and 15 inches long and about 8 inches tall. These are BIG fish. Note that the large Goldfish above the one Pacu is almost 5 inches long!