The term "hisser" applies to pretty much any roach that produces a hissing sound, this includes many species from several different genera, most are found in Madagascar. Elliptorhina may be known as "dwarf" hissers and include species like javanica, laevigata, and chopardi. Elliptorhina will not hybridize with, say Gromphodorhina, which is what you have here. Gromphodorhina includes larger species that still produce the hissing sound, like Oblongonata, grandidieri, and portentosa. Aeluropoda also produce "hissing" sounds, but will not hybridize with the above two genera.