http://www.franksaquarium.com/ often has various species in stock. Every once in a while I've been able to find Stiphodon, Sicyopus and Rhinogobius sp. very randomly at local and not-so-local fish stores. I've got about 3 different Rhinogobius sp. in one of my 50 gallon tanks right now. Found them at a fish store that called them "Dancer Gobies".[FONT=arial,sans-serif][SIZE=-1]
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