Acipenser ruthenus(sterlet sturgeon) one of the smaller stugeon species.. rarely attains a length over 3'(in captivity)...in it's natural habitat can reach over 4'...you need a larger tank than a 150..it is recommend atleast 300 gallon aquarium. this species , as are most sturgeons, is a bottom dweller.
it is also a cool water species..warm water max 74 degrees for short period during the summer. It is recommended to try and keep the water temp between 54-65 degrees. and recommended to air airation if the temp get around 70.
it is also recommended to have very good circulation and water current.(many species of sturgeon live in rivers..aka oxygenated moving water.)
the water should be very clear and clean.
judging from the parameters..you would need exception filtratio, a large tank, lots of water movement(river tank) and most likely a chiller. to keep this species would be a bit daunting for the average hobbyist.