Enormous halibut from the Trondheimsfjord

Enormous halibut from the Trondheimsfjord

Photo: Sverre Magnus Selbach

Halibut are common in theTrondheimsfjord. But the one that was caught off Trondheim in 2016 was especially large. It was 219 cm long, had a circumference of 207 cm, and weighed 161.6 kg after it was cut up.

The head from the halibut was cleaned, degreased, bleached and reassembled in an anatomically correct position.

You can see the halibut head in the NTNU University Museum's foyer from March to September 2021.

Description of exhibited objects

1. The head from the halibut
After the halibut was caught, its head was cleaned, degreased and bleached. It was then reassembled using glue and wire. You can see the great result here.

There are two methods that are suitable for cleaning a skeleton. Most larger animals are immersed in a liquid that accelerates decay. Fragile and small animals, such as fish, reptiles and small birds, can be cleaned using scavenger beetles.

The work with the halibut head was carried out by conservator Guus Wellesen.

2. Otoliths
Otoliths can also be called ear stones. They are part of the organ the fish uses for balance and directional movement, and register changes in the fish's position.

The otoliths also record the fish's growth. Growth rings are laid down in the otoliths much like the annual rings of a tree. This allows scientists to determine the age of the fish. The otoliths also make it possible to say something about what kind of diet the fish has had or the water temperatures it has lived in, by studying different elements from the otoliths.

3. Fishing rod and rubber jig
This fishing rod is a Prey Jigger 12-30 lb with a Makaira 8 reel with 0.36 mm braided line. A large rubber jig was used at the end of the line.

The rod is intended for a lighter class of fish than for a halibut of this size. With patience, technique and a little luck, it went well. The fish swallowed the entire rubber jig, which made it impossible to remove before the fish was cut up.

Photos Halibut

Photo: Sverre Magnus Selbach