They are the most valuable of the cetacea, except perhaps the cachelot or sperm whale, as producing the greatest amount of oil and whalebone. Of the various species the most sought after is the Greenland or right whale (Balæna mysticetus), which ordinarily attains a length of fifty to sixty feet. An average whale between forty and fifty feet in length will yield from sixty to eighty barrels of oil and a thousand pounds of baleen.
| Br, brain cavity; J J*, upper and lower jawbones; the arrows indicate narial passages; S, spout-hole; W, whalebone; t, tongue in dotted line; n, nerve aperture in lower jaw; bo, bone sawed through. |
| Skull of Baleen Whale. |
Formerly all whaling vessels were sailers, but now powerful steamships are used, and the harpoon often gives way to the harpoon gun. A whale, when struck, will sometimes run out a mile of line before it comes up again, which is generally in about half an hour. The whalers judge as best they can, from the position of the line, in which direction he will rise, and get as near as possible so as to use the lance or drive in another harpoon. When killed, the animal is towed to the vessel and fastened on the port side, belly uppermost, and head towards the stern; it is then stripped of its blubber, the body being canted by tackles till all parts are cleared. The baleen is then cut out, and the carcase abandoned to the sharks, killer whales, and sea birds.
The baleen whales are not found in the intertropical seas. Of the known species there are the Greenland whale (B. mysticetus), the Biscay whale (B. Biscayensis), the Japan whale (B. Japonica), the Cape whale (B. australis), and the South Pacific whale (B. antipodarum).
[GENUS BALÆNOPTERA—FINBACK WHALES OR RORQUALS.]
Are distinguished by their longer and narrower bodies, smaller heads, being one-fourth instead of one-third the length of the body, smaller mouths, shorter baleen, plaited throats, and smaller flippers; they have a dorsal fin behind the middle of the back, and the root of the tail is compressed laterally. They also present certain osteological differences from the right whales; the latter have the whole of the seven cervical vertebræ anchylosed, that is to say generally, for sometimes the seventh is free. In the finbacks the cervical vertebræ are, as a rule, all distinct and free, although occasionally anchylosis may take place between two or more of them. The sternum of the Balæna consists of a broad, flattened, heart-shaped or oval presternum. "In the fin whales (Balænoptera) it is transversely oval or trilobate, with a projecting backward xiphoid process" (Professor Flower). The ulna and radius in the rorquals are also comparatively longer than in the baleen whales. In the skull, the supraorbital processes of the frontals are broader in the rorquals than in others, and the olfactory fossa is less elongated.
They are more muscular and active animals than the right whales, and have a less amount of blubber and much shorter whalebone, consequently are not so much sought after by whalers, as the risk in attacking them is not compensated for by the commercial results. Many of them grow to enormous size, far exceeding any of the baleen whales. The common rorqual, razorback, or pike-whale of the English coasts (B. musculus) attains a length of seventy feet; it is black above and pure white below. The sulphur-bottom whale (B. sulfureus) is known by its yellowish belly, and with Sibbald's whale (B. Sibbaldii) grows to a length of one hundred feet, to which size our Indian species also approaches.
[NO. 271. BALÆNOPTERA INDICA.]
The Indian Rorqual (Jerdon's No. 147).
HABITAT.—The Indian Ocean.