10 20 40 60 cm
mittakaava < 10 cm
Gösta Sundman: Suomen Kalat (Kansalliskirjasto, The National Library of Finland), Lauri Urho
- Family: Gobies – Gobiidae
- Similar species: common goby, round goby, sand goby, two-spotted goby
- Size: 5–7 cm, max. 10 cm.
- Appearance: Stockier-bodied than the sand, common and two-spotted gobies with a blunter snout, also slightly larger in size. Distinguished from the round goby, a fairly new arrival in Finnish waters, which grows much bigger, is more stout-bodied and has a more rounded snout. Like most other gobies, the black goby has fused pelvic fins. The first dorsal fin has six spiny rays and is much higher than the second dorsal, which has soft rays. Spiny rays of first dorsal may protrude beyond fin membrane, which is joined to that of second dorsal. Second dorsal fin much longer than distance between its posterior edge and caudal fin. In other Finnish gobies the reverse is true, the exception being the round goby, which has an even longer second dorsal.
- Colouring: Brown or dark brown with irregular darker bar-like patches. Overall, the colouring is very dark. Spawning males become almost completely black and the fins more showy.
- Reproduction: Spawns in summer. The male stakes out a territory in weedy shallows. He then invites the female to inspect the spawning bed prepared on a clean, hard bottom. Like other gobies, the male remains to guard the eggs.
- Food: Small benthic invertebrates.
- Distribution and habitat: The black goby is found along the coast in the area extending from Virolahti in the Gulf of Finland to Kristiinankaupunki in the Gulf of Botnia. Prefers bladderwrack cover and a muddier bottom than other Finnish gobies.