Balaenoptera edeni

Bryde's whale (/ˈbrʊdəz/ BRUU-dəz), or the Bryde's whale complex, putatively comprises two species of rorqual and maybe three. The 'complex' means the number and classification remains unclear because of a lack of definitive information and research. The common Bryde's whale (Balaenoptera brydei, Olsen, 1913) is a larger form that occurs worldwide in warm temperate and tropical waters, and the Sittang or Eden's whale (B. edeni, Anderson, 1879) is a smaller form that may be restricted to the Indo-Pacific. And lso, a smaller, coastal form of B. brydei is found off southern Africa, and perhaps another form in the Indo-Pacific differs in skull morphology, tentatively referred to as the Indo-Pacific Bryde's whale. The recently described Omura's whale (B. omurai, Wada et al. 2003), was formerly thought to be a pygmy form of Bryde's, but is now recognized as a distinct species. B. brydei gets its specific and common name from Johan Bryde, Norwegian consul to South Africa, who helped establish the first modern whaling station in the country, while B. edeni gets its specific and common names from Sir Ashley Eden, former High Commissioner of Burma (Myanmar). Sittang whale refers to the type locality of the species. In Thailand, locals distinguished Sittang whales that were different from B.edeni, and it is unclear whether Sittang whales were applied for later-classified Omura's whales by locals. In Japan, early whalers called it 'anchovy' (鰯, iwashi) or 'skipjack whale' (鰹鯨, katsuo-kujira). It preys on the anchovy and it was commonly associated with the skipjack. As modern whaling shifted to the Sanriku area, whalemen confused the sei whale with it; now iwashi-kujira (鰯鯨, 'anchovy whale') only applies to the latter. Incidentally, anchovies are dominant prey for both species off Japan. They are now called nitari-kujira (似鯨, 'look-alike whale'), for their resemblance to the sei whale. The taxonomy is poorly characterised. The two genetically distinct, candidate species/subspecies/morphologies are Bryde's whale B. brydei and the Sittang or Eden's whale B. edeni, that differentiate by geographic distribution, inshore/offshore preferences, and size. For both putative species, the scientific name B. edeni is commonly used or they are simply referred to B. cf brydei/edeni. In 1878, the Scottish zoologist John Anderson, first curator of the Indian Museum in Calcutta, described Balaenoptera edeni, naming it after the former British High Commissioner in Burma, Sir Ashley Eden, who helped obtain the type specimen. Eden's Deputy Commissioner, Major A.G. Duff, sent a Mr Duke, one of his assistants, to Thaybyoo Creek, between the Sittang and Beeling Rivers, on the Gulf of Martaban, where he found a 37-foot whale, which had stranded there in June 1871 after swimming more than 20 miles up the creek—it was said to have 'exhausted itself by its furious struggles' to get free and 'roared like an elephant' before finally expiring. Despite terrible weather, he was able to secure almost the entire skull and nearly all its vertebrae, along with other bones. These were sent to Anderson, who described the specimen, which was physically mature, as a new species. In 1913, the Norwegian scientist Ørjan Olsen, based on the examination of a dozen 'sei whales' brought to the whaling stations at Durban and Saldanha, in South Africa, described Balaenoptera brydei, naming it after the Norwegian consul to South Africa Johan Bryde. In 1950, the Dutch scientist G.C.A. Junge, after comparing specimens of B. edeni and B. brydei with a 39-foot, physically mature specimen that had stranded on Pulau Sugi, an island between Singapore and Sumatra, in July 1936, synonymized the two species into B. edeni. In the 1950s it was discovered that there were two types of 'sei whale' off Japan, a northern form with longer, finer baleen and shorter ventral grooves and a southern form with shorter, coarser baleen and longer ventral grooves. They also differed in the shape of the palate. The former was caught off northeastern Honshu and eastern Hokkaido, while the latter was taken off western Kyushu and southern Honshu. Both were caught off the Bonin Islands, but at different seasons. It was realized that the northern form were indeed sei whales (B. borealis), but the southern form were Bryde's whale (B. brydei/edeni). A later study revealed that Bryde's caught off Japan exhibited lateral ridges on their rostrum, whereas sei whales lacked this feature. In the 1960s it was discovered that some of the 'sei whales' being caught off Brazil were also Bryde's whales based on the same characters that distinguished the two species off Japan (i.e. three ridges on the rostrum versus one, shape of the palate, texture of the baleen, length of the ventral grooves). Several differences in anatomy are seen between Bryde's and Eden's whales; morphological similarities have caused confusions regarding species identification.