10 20 40 60 cm
mittakaava < 20 cm
- Family: Gobies – Gobiidae
- Similar species: black goby, common goby, sand goby, two-spotted goby
- Size: 10–20 cm, max. 25 cm.
- Appearance: Like most gobies, the round goby has fused pelvic fins and a first dorsal fin with 5-7 (usually 6) soft spiny rays. The long anterior dorsal fin has 14-17 rays and the anal fin 12–15. Body slightly deeper and stockier than other gobies, snout blunter and the eye smaller in proportion. Scales rather small, numbering 49–58 along the lateral line. First dorsal fin much lower than that of the black goby, which it otherwise resembles. The round goby is by far the biggest of the family found in Finland.
- Colouring: Dark greyish with black and brown markings. Distinctive black spot on first dorsal fin. Males almost black at spawning time.
- Reproduction: In spring males move into shallow water, where they mark out a spawning territory. Having attracted one or several females to deposit their eggs in the nest, the male remains to guard the eggs as they develop. Spawning continues until autumn. The round goby is a fairly new species in Finland and little is so far known about its spawning habits in Finnish waters.
- Food: Molluscs and other small benthic invertebrates.
- Distribution and habitat: The round goby originates from the Black Sea and Caspian Sea, and is thought to have spread to the Baltic via ship’s ballast water. First encountered in Finnish waters in the SW archipelago in 2005, since when there have been reports from several areas, including the sea off Katajanokka, Helsinki, in 2009.
- Harmfulness: Harmful invasive species.