The Bryde's Whale
The Bryde's whale is a baleen whale and is unique in having 3 longitudinal ridges on its head, forward of the blowhole, while all other rorquals have just one. The whale can grow to a length of 12.5m (41ft) to 14m (46ft) and a weight of 26 tonnes with the female larger than the male. There has often been confusion between the Sei whale and the Bryde's whale as they are similar in both size and appearance.
The head of the Bryde's whale at close range is unmistakable because of its three longitudinal ridges. The ridges are normally 1 - 2cm (.5 - .75in) high but the two outer ridges may not be as prominent and do not reach the tip of the snout. At their other ends, near the blowhole, they disappear from the surface and change into grooves of varying lengths. The grooves may be absent in some indiduals but the central ridge is continuous.
Although usually dark grey in colour some Bryde's have a lighter grey area between the head and the dorsal fin over the back and occasionally as a band down the flanks. The chin a belly are said to be white. The whale's 40 - 70 throat groves may be yellowish white in some areas and usually end at or behind the navel. The flippers are relatively short at only one-tenth of its body length. The skin on the underside towards the tail may be light purple-grey, blue-grey or creamy grey and may appear mottled with circular scars caused by parasites or Cookie-cutter sharks. The flukes are broad, distinctively notched and have a slightly concave trailing edge.
The Bryde's whale has twin blowholes with a low splashguard to the front. It has no teeth but in their place are two row of baleen plates. The plates which number 250 - 410 are short and wide, with a maximum length (excluding bristles) of 50cm (20in) and a width of about 19cm (7.5in). The left and right rows of baleen plates may be separated by a gap at the front of the mouth. The baleen colour varies between individuals with most being black or slate-grey, though the plates near the rostrum are often completely or partially creamy white and sometimes with grey stripes. Baleen bristles are long, stiff, uncurled and generally brownish or greyish in colour.
Other Names: Tropical Whale
The Bryde's whale has a prominent dorsal fin which is relatively tall (though smaller than the Sei whale), strongly sickle-shaped, and situated about two thirds along the back. The trailing edge is sometimes notched or frayed.
There may be 2 distinct groups in some areas one occurring offshore and partially migratory and the other living inshore and resident all year-round. The two forms differ slightly in their reproductive behaviour and the offshore animals are usually larger, have more scaring and have longer and broader baleen than the inshore variety. There may also be a 'dwarf' form around the Solomon Islands.
The Bryde's whale prefers water temperatures above 20°C (68°F) so it is most common in coastal areas of tropical and subtropical waters of all seas. Some tropical populations are possibly sedentary with most migrating short distances with no known long-distance migrations to higher latitudes. Bryde's range in the Pacific from Japan and southern California south to northern New Zealand and Chile. In the Atlantic, southeastern United States and the Strait of Gibraltar south to Brazil and beyond the southern tip of South Africa. They range throughout most of the Indian Ocean.
Some Bryde's whale populations have been depleted by whaling. Japan continued killing Bryde's whales until 1987. In that year three companies were operating a total of five catcher boats ranging from 400 to 600 tons, and took 200 sperm whales and 317 Bryde's whales. Although not on the Endangered list, the Bryde's Whale is protected (since 1986) worldwide by the Moratorium on Whaling. It should not to be hunted by anyone for any reason at all.