These three pictures (two behind the fold) feature, apart from gudgeons, a small turbot. See if you can spot the turbot in the first picture.
In the second picture, the turbot is decloaking.
In the third one, it’s gone back into hiding.
The brackish waters in the saltier parts of the Gulf of Finland and the Gulf of Bothnia are on the limit for the turbot. They cannot procreate in the low-salinity waters far from the central basin of the Baltic sea.