Editing Round goby (section)

==Characteristics==
Round gobies are small, soft-bodied fish characterized by a distinctive black spot on the first dorsal fin. The eyes are large and protrude slightly from the top of the head and, like most gobies, the pelvic fins are fused to form a single disc (shaped like a suction cup) on the belly. Round gobies range in length from {{convert|4|to|10|in|cm|order=flip|abbr=off}}, with a maximum size of {{convert|24.6|cm|in|abbr=on}}. They weigh between {{convert|0.176|and|2.816|oz|g|order=flip|abbr=off}}, their weight increasing with age. Male round gobies are larger than females. Juvenile round gobies (less than one year old) are grey. Upon maturation, round gobies become mottled with grey, black, brown, and olive green markings. Adult male round gobies turn inky black during the spawning season and develop swollen cheeks. Male and female round gobies are easily differentiated by the shape of their urogenital papilla, which in males is white to grey and long and pointed and in females is brown, short, and blunt-tipped. {{citation needed|date=September 2021}}