Tadpole-fish
Otolith description
The shape of the otoliths is ovally rounded. The sulcus is well developed and wide. The sulcus is closed and runs over of the length of the otolith. The ostium and cauda are well developed and separated by a parting of the sulcus. Ostium and cauda are both ovally shaped. The surface of the inside and margins is smooth, while the outside is lobate. There is also one strongly protruding, remarkable lobe at the outside. The rostrum is not well developed and round. The antirostrum is indistinct. The inside of the otolith is convex and the outside slightly concave. The otolith is thick and more robust than in most other gadidae.
Tadpole-fish otoliths can be distinguished from other gadidae because of the parted sulcus and the strongly protruding lobe at the outside.
In eroded otoliths the sulcus is less clear. The outside remains lobate and the one lobe remains strongly protruding.
Fish length and distribution
Tadpole-fish can grow up to 30 cm. Tadpole-fish is a solitary living bottom fish (RANIRANI.TIF) found among algae covered rocks in shallow waters. It spawns inshore from May to September (Wheeler, 1978, Nijssen and De Groot, 1987, Knijn et al., 1993, Muus et al., 1999).
Tadpole-fish is found on the shores of the NE Atlantic and North Sea.
Sample origin
Around Helgoland, southern North Sea.