Read the facts about Bryde’s whale or sei whale. Sei (pronounced “say”) and Bryde’s (pronounced “broadus”) whales are so similar that it was not until the early 1900’s that the whalers realized they were hunting two different species.
Bryde’s whale is named after Johan Bryde, who initiated the South African whaling station where Bryde’s whales were first described.
Field identification between the two species is still difficult until one is close enough to see whether there are three ridges on top of the head (Bryde’s whale) or just one (sei whale).
To add to the confusion, some populations of Bryde’s whales vary in size, colour, and baleen structure in different geographical locations .lets find more facts about Bryde’s whale,
Physical Description of Bryde’s whale
Sei and Bryde’s whales look very much alike, with only minor physical differences. Both species, like other rorquals (whales with a dorsal fin and long throat grooves on the lower side of their bodies) are slim and streamlined. The most noticeable difference between them is that the sei whale has a single ridge running from the tip of the snout to the blowholes, while the Bryde’s whale has three ridges. The sei has 32 to 60 throat grooves, while the Bryde’s has 40 to 50 throat grooves.
Sei whales have a bluish-grey body with white on the underside. Some of them have dark grey or almost white scars that may be caused by bites of lampreys (fish that attach themselves to the skin and bore into the flesh of some whales).
Fins and Fluke
The pectoral (side) fins are relatively short (only 9% to 10% of the body length) and pointed at the tips. The sei whale has a tall, falcate (curved) dorsal (top) fin. The dorsal fin is located about one-third of the body length forward of the notch in the fluke (tail). The flukes are also relatively small in relation to body size.
Length and Weight
The adult male sei whale measures 13.7 to 16.8 meters (45 to 55 feet), sometimes reaching a length of 19.8 meters (65 feet), and weighs about 14 to 17 tons.
Sei whales are baleen whales; they have a series of fringed, overlapping plates that hang from the upper jaw where teeth would be. The plates are composed of a fingernail-like material called keratin that frays out into fine hairs on the ends and inside the mouth next to the tongue. Sei whales have 320 to 380 baleen plates on each side, which are about 48 cm (19 inches) long. The plates are black outside, with a white fringe that is very fine and silky. Bryde’s whales have 250 to 350 baleen plates on each side, which are about 42 cm (16 1/2 inches) long. Some of the baleen plates in the front of the mouth are white, while the rest of the plates are black. The fringe is stiff and coarse.
The fine baleen of the sei whale adapts it for feeding on its favourite food, copepods (small crustaceans). There is some variation in their diet: they frequently eat fish in the North Pacific and krill (small, shrimp-like crustaceans) on occasion. The sei feeds on plankton (marine animal and plant organism that drifts or floats with currents and waves), which means it spends prolonged periods on the surface. Like right whales, they often open their mouths and skim the surface for their food. When doing this they blow or spout once every 1 to 2 minutes.
Mating and Breeding
Male sei whales reach sexual maturity at about 12.2 meters (40 feet), females at about 13.1 meters (50 feet), and at about the age of 10. The gestation period is 11 1/2 to 12 months, with calving taking place up to once every two years. Size at birth is 4.3 to 4.6 meters (14 to 15 feet). Weight at birth is about 2,000 pounds. Calves nurse for about 6 months in both species. Little else is known about the mating and breeding of these whales, although mating may occur year-round
some sources from WDC