Stratospongilla sumatrana typically forms irregular-shaped or circular thin-layered encrustations on submerged hard objects, and its body surface is smooth. The skeleton is loosely structured but compact, composed of large, thin spicule fibers, resulting in a rather hard consistency. The color of the sponge in life is usually light grey. The megascleres are more or less straight, fusiform, and those with pointed ends (amphioxea) bear minute spines except at their terminal ends. Their dimensions range from 210-290 µm in length and 9-14 µm in width. Microscleres, specifically amphioxea, are weakly curved and sharply pointed at both ends, completely covered with tiny spicules. Their dimensions range from 47-65 µm in length and 3-4 µm in width. Gemmoscleres, also amphistrongyla (blunt or rounded at both ends), are feebly curved to straight, stout, short, and covered with quite uniform minute spines. The length and width of gemmoscleres range from 32-43 µm and 11-13 µm, respectively. Gemmules are not numerous in mature sponges, and the pneumatic coat is irregularly formed without definite air spaces. The foraminal tube is short, straight, and porous. Gemmoscleres surrounding this tube are rather slant and form crater-like depressions around micropyles. The diameter of the gemmules ranges from 370-450 µm.