Common goby
Otolith description
Otoliths of gobiidae are all very similar in shape and are hard to identify to species level. The shape of common goby otoliths is square. The sulcus is closed and runs diagonally. The ostium is slightly wider than the cauda. The cauda sits dorsally from the ostium. The surface of the inside, the outside and margins are smooth. There is a small rostrum visible, which is rounded. The antirostrum is also rounded but slightly smaller than the rostrum. The posterior margin is lobate. The dorsal margin is rounded, while the ventral margin is straight, giving the otolith the shape of a cumulus cloud. The inside of the otolith is flat and the outside convex. The otolith is thick. Otoliths of common goby do not exceed 2.0 mm in length.
Otoliths of gobiidae are all very similar. The antirostrum is indistinct in otoliths of black goby Gobius niger. Otoliths of transparent goby Aphia minuta and crystal goby Crystallogobius linearis are round instead of square and the inside of the otoliths is convex. In transparent goby there is hardly a cauda visible. On otoliths of crystal goby the whole sulcus is indistinct. The rostrum of painted goby Pomatoschistus pictus is not as well-developed as in some other gobiidae otoliths. Sand goby P. minutus otoliths also have a distinct antirostrum which is lobate. Otoliths of Lozano’s goby P. lozanoi do not have a well-developed rostrum and the posterior end is only slightly lobate or round.
When eroded the above described differences disappear and are therefore not useful for identifying otoliths to species level. Eroded gobiidae otoliths are round with the sulcus slightly visible.
There is some difference in the maximum size of the fish and therefore in the otoliths:
crystal goby: <0.7 mm
transparent goby: <1.5 mm
common goby, Lozano’s goby: <2.0 mm
painted goby: <2.5 mm
sand goby: <3.0 mm
black goby: >3.0 mm
Fish length and distribution
Common goby can grow up to 6.5 cm. Common goby is a fish (POMAMICR.TIF) found closely inshore, in estuaries and brackish waters. It is mostly found on muddy grounds. In winter it migrates to deeper waters of the coastal zone. Spawning takes place from April to August (Wheeler, 1978, Nijssen and De Groot, 1987, Witte et al., 1991, Muus et al., 1999).
Common goby is found in the coastal waters of the NE Atlantic, North Sea and Baltic.
Sample origin
Western Wadden Sea.