Sicyopus is a genus of small amphidromous gobies closely related to Sicyopterus, found in fast-flowing streams on tropical Pacific islands. The atlas covers 5 species ranging from roughly 1–2.5 in, with records from the Philippines, Indonesia, and Papua New Guinea. Like its sister genus, Sicyopus has pelvic fins fused into a sucker disc used to cling to and climb wet rock in swift current, but its species tend to run smaller and are typically found perching on boulders and rock faces in fast riffles rather than grazing broad open rock sheets.
Sicyopus zosterophorus, the banded rockskipper goby, is the best-known species in the genus, occasionally reaching specialist aquarium keepers drawn to its bold banded pattern and territorial, rock-hugging behaviour, though like other sicydiines it carries an obligate marine larval stage that makes captive breeding essentially unfeasible, so any aquarium specimens are wild-caught. The remaining species, including S. auxilimentus, S. cebuensis, S. exallisquamulus, and S. rubicundus, are known mainly from regional ichthyological surveys of Philippine and Indonesian island streams and have little to no presence in the hobby. With four of the five atlas species not yet evaluated and one rated Data Deficient, almost nothing is documented about the genus's conservation status, a gap typical of small, range-restricted island stream gobies.