The scientific name for the sei whale means winged whale and northern and is also known as Rudolphi's rorqual. The name sei is derived from Norway and means coalfish. They are smaller than the fin whale but are very fast and have been noted to travel substantial distances in short periods of time. The sei whale is usually found on its own or in small groups and this species of whale usually avoids the coldest of the worlds oceans unlike the blue and fin whale who go into higher latitudes.

The sei whale is dark grey in colour on its sides, back and the hind part of its underside. They have a dorsal fin that is curved and smaller than that of the blue or the fin species of whale. Bites from the cookie cutter sharks that live in the same warm waters leave them with areas of scaring on their bodies.

A sei whale can reach 20m or 66ft in length but the average length is around 8-15m or 25-50ft. The male of the species is slightly smaller than the female by approximately 1m of 4ft and they can weigh anything up to25 tons.

This species of whale skim feeds on plankton but also consumes small schooling fish and squid. Out of all of the rorqual families it is the most versatile feeders and is the only one to have such feeding habits. They utilise some 650 plates of baleen to filter out water from their mouths and retain their prey.

The sei whale will reach sexual maturity around the age of 6-12 years with the gestation period for a calf lasting one year. When the calf is born it can measure 4.5m or 14ft. The female of the species will normally produce a calf one every two to three years.

First grade oil from the blubber which is edible was used for the manufacturing of margarine, and also in the production of soft soap. Oil was also extracted from meat and bones after they were pressure cooked. Meat extract was also produced from the meat and was very edible similar to branded meat extract drinks. The liver was also processed to produce liver oil for medicinal purposes. The meat residue from the pressure cookers was rendered down to make cattle feed and fertilizers. The baleen plates from the mouth which in the olden days were used for stays for ladies corsets but in modern whaling the baleen plates were discarded.