luck!
keep in mind that ottos can be a very difficult fish to keep alive. they need a well seasoned tank and even then the mortality rate is rather high. we have ottos in all our tanks and generally expect a 25-50% loss in the first 2 months. the ones that survive live a good long time.
the mortality issue stems from the wild caught fish. the bacteria in their gut that is needed to digest algae dies in transit. so when they finally get to the home aquarium they can eat and eat and be fat and seemingly happy and then die. it is not the fault of the fish keeper. 