Haddock
Otolith description
The shape of the otoliths is ovally pointed. When viewed from the side the otolith is strongly curved. The sulcus is well developed and wide. The sulcus is closed, but runs over almost the whole length of the otolith. The ostium and cauda are well developed and separated by a narrowing of the sulcus. The cauda is longer than the ostium. The surface of the inside is smooth, while the outside and margins are lobate. The rostrum is not well developed and round lobate. The antirostrum is indistinct. The posterior margin is pointed. The inside of the otolith is convex and the outside strongly concave. Otoliths of gadidae, except rockling otoliths, are all very large and mostly robust otoliths.
Haddock otoliths are often hard to distinguish from other gadidae. Cod Gadus morhua is less concave and more lobate at the outside compared to haddock otoliths. Whiting Merlangius merlangus and blue whiting Micromesistius poutassou are flatter and thinner and the otolith length-width ratio is larger than in haddock otoliths, their posterior margin is more pointed. Otoliths of whiting and blue whiting are thinner than other gadidae otoliths. Otoliths of Trisopterus spp. are thicker and more lobate at the outside, while their otolith length-width ratio is smaller. Otoliths of Pollachius spp. are more concave on the outside. These otoliths are not only strongly curved from the anterior to the posterior but also from the ventral to the dorsal side. The sulcus of Pollachius otoliths is wider than in haddock otoliths. Otoliths of tadpole-fish Raniceps raninus have a sulcus in which the ostium and cauda are completely separated. Tadpole-fish otoliths are flat and have one strongly protruding lobe on the outside of the otolith.
In eroded otoliths the sulcus is less clear and the margins are smoothed. The outside remains lobate.
On otoliths of juvenile haddock the sulcus is not well developed. The margins and outside are already slightly lobate.
Fish length and distribution
Haddock can grow up to 100 cm. Haddock is a common demersal fish (MELAAEGL.TIF) that is found in a variety of habitats and water depths, but always close to the bottom. In the northern part of its range it is found in shallow water close to the shore in summer while in the southern part of its range it is found in shallower water during winter. It spawns from March to June (Wheeler, 1978, Nijssen and De Groot, 1987, Witte et al., 1991, Knijn et al., 1993, Muus et al., 1999).
Haddock is a very common fish found in the NE Atlantic, North Sea and Baltic.
Sample origin
Central North Sea.