Giant Sperm Whale


giant sperm whale Kaikoura

In the last 140 years the Sperm Whale's proper name has changed at least four times due to biologists disagreeing on what it should be remembered as. However for the time being its name is Physeter Macrocephalus.'

Physeter - from the Greek for whirlpool or wind instrument.
Macrocephalus- from macro (large) and cephalus (head).

Sperm Whales are prolific around Kaikoura because of the deep Hikorangi Trench. This trench runs about 1000 m deep, but can in places delve to 2000 m. The shape of this trench, combined with the predominance of Northerly and Southerly tides in the area, ensures that there is an ample food supply of Squid, Groper, Ling and Shark for the Sperm Whale.

In Kaikoura, whales usually spend 10 minutes on the surface, breathing every 10-15 seconds. On average, a Sperm Whale takes one breath for every minute that it subsequently stays submerged. When breathing, the whale re-oxygenates approximately three tonnes of blood with the haemoglobin in the blood absorbing the oxygen. The blood is circulated around the body and the haemoglobin in turn transfers the oxygen to a material called myoglobin in the muscle and body tissue. When diving, the whale does not have oxygen in its lungs, or rather does not rely on the oxygen that it has remaining in its lungs, but instead utilises the oxygen held in the blood and body tissue.

Whales typically dive and return to the surface vertically, which may explain the relative ease with which the whalers were able to hunt them. When they dive they descend at approximately 4 knots (7 - 8 kph) and return to the surface at about 5 knots (9 kph). The whales around Kaikoura normally dive down to 3,000ft (1,000m) for approximately 45 minutes; however, they are capable of diving for more than 2 hours and at other locations have been tracked to a depth of 7,000ft (2,300m) and may be able to dive to far greater depths



Identification
Male

Length: 18 m (max- 22m)
Weight: 36000kg (max.42000kg)


Female

Length: ll m (max. 17m)
Weight: 20000kg



The whale has a long, smooth, blunt head which occupies approximately 1/3 of its total body length and considerably more than 1/3 of its body mass. As a consequence this whale has been described, not without foundation, as the animal with 'the biggest nose on record,' being up to 5 m long. The skin around the head of most Sperm Whales is often patterned with circular scars, most likely from squid. Some scars have been 12cm in diameter, meaning the leg of the squid would have had to be about 60cm in diameter, while scars 20cm in diameter suggest squid up to 45m long!

Within the whale's large head is a reservoir of a clear liquid, which upon cooling sets to a semi-solid white wax. This product, because of its similarity to semen when cooled, was called Spermaceti (literally whale semen) by early whalers. The whale uses this material to control its buoyancy while diving.

The blowhole, which is on the front left of the whale's head, creates a spout that is blown at a forward angle of about 45° and is 3 - 5 metres high. The first exhalation after a long dive is like an explosion and can be heard up to 1 km away.

The Sperm Whale has no dorsal fin, but rather a dorsal hump made of flesh and fiber that appears 2/3 down it's back. Further back are 4 or 5 humps that look similar to the back bone. The flippers are short and stubby and apparently function primarily as brakes. The tail flukes are large and powerful, their area being proportionately greater than any other whale, and they provide for rapid acceleration.

The entire skin of the whale appears shrivelled due to the surface being corrugated. Its colour is a steel grey with white patches around the lips, and white blotches may be found in other areas of the body, for example, streaked along the flank and tail. The number and area of these white patches increase with age, and older males in particular may turn pure white, just like the legendary Moby Dick.

Sometimes when digesting squid, a whale develops an irritation in its stomach which results in a flow of bile that builds into a dark resinous mass within the whale's stomach. From here it passes to the intestine where it forms a soft round mass and develops further. After a period of time, this lump is excreted and eventually drifts ashore. This product, called Ambergris, consists of non-volatile alcohols and is most commonly found in the sea in the tropics. It is highly valued for its ability to stabilise and intensify fragrances of perfumes, and as an antispasmodic drug. Lumps up to 420 kg have been found in commercially captured whales. Sperm whales communicate with other whales in a manner similar to dolphins, with a series of 'clicks' (or codas). However they can, like dolphins, use sonar to confuse their prey while hunting.