Gymnoxenisthmus tigrellus, is a species of family Xenisthmidae, regarded as a synonym of the Eleotridae. This species is endemic to Red Sea occurring near an unnamed island in Farasan Archipelago, Red Sea, Saudi Arabia where it is found on a narrow reef flat at depth. the area consisting of a sandy slope with patches of corals and near a rock face of in height which had small caves and rock shelters. This species is the only known member of its genus.