In the Saltfjord in Norway, the Akvaforsk Institute runs a halibut breeding and research station with the aim of increasing the stocks of that fish in the Norwegian Sea. Here, biologist Solveig van Nes examines the development of the larvae and juvenile halibut. She has, for example, discovered that it is the temperature of the water that determines the sex of the larvae. Growing to as much as three-and-a-half metres in length, the halibut is the largest member of the flatfish family and lives a secret life in the dark depths of the northern oceans. Well camouflaged, concealed under the mud on the seabed, this permanently hungry predator keeps a lookout for its favourite dinners: salmon, mackerel, cuttlefish and smaller bottom-dwellers. It has to keep a watchful eye open to ensure it does not become the prey, instead.
In San Diego (California) we visit "Hubbs Seaworld Research Institute" where we witness the fascinating metamorphosis of halibut larvae under the microscope.
As a baby fish, the halibut looks "normal" and lies down on its side where it commences its life as a bottom-dweller. The eye which is underneath slowly moves until it is on top.
The name "halibut" comes from an Old Norse translation, which considered the fish to be "holy" and it was mainly eaten on feast days. Fishermen often refer to the halibut as a hali or barndoor.
Researchers at the Pacific Halibut Commission track the flatfish using satellite transmitters as they migrate from the deep oceans to their summer hunting grounds nearer the shoreline. During the mating period, the males perform deep-sea dances to impress the females in which they repeatedly swim up several hundred metres and back down within remarkably short times…
