He is a Malaysian Marbled ( no option for marbled goby ) goby they are very aggressive but live well with the black algae eaters or plecostomus fish. He is about 8 1/2 inches and will get bigger. Eats live food like gold fish. Are for the most part very territorial. He will cover himself in sand and sub strait and even change shades of color and patterns. I also will give you a plecostomus he lives with for free.