About 6 cm. The scientific name of Seven-star Perch is Flower Perch. Adults weigh 3-5 pounds and are 30 to 40 centimeters long. The 2-tael Seven-Star Bass is about 6 centimeters long. Seven-star Perch, whose scientific name is Flower Perch, is also known as Japanese Flower Bass and Japanese True Bass. It is a euryhaline fish species. , it can survive a wide range of salt concentration changes in the outside world, so Seven Star Bass grows in fresh water, brackish water and sea water.