Japanese Sicyopterus Goby

Sicyopterus japonicus is one of the most ecologically fascinating freshwater gobies in the world. Found in Japan, Taiwan, and the Philippines, it is an obligate amphidromous species whose post-larval juveniles famously migrate upstream from the sea, climbing waterfalls using a unique combination of the pelvic suction disc and the mouth as a second suction organ. In breeding condition, males transform into intensely beautiful fish with a turquoise-blue iridescent sheen covering the entire body, vivid fin colouration, and dramatic display behaviour. This species is a strict aufwuchs grazer and requires a mature biofilm to survive long-term in captivity. Water must be cool, fast-flowing, and highly oxygenated. It is an advanced-level fish that rewards patient, experienced aquarists with one of the most spectacular displays in the freshwater goby world.