Physeter macrocephalus - The Sperm Whale

Enormous macrocephalus brain

Where to begin with this one? The sperm whale is surely one of the best known animals in the world and has captured the imaginations of writers and artists for centuries. What do you know about them? What do you think of when you hear the name? Let's start with the name. Physeter comes from the Greek for blowhole. The sperm whale, like all toothed whales, has a single blowhole, while the baleen whales have a pair (similar to our nostrils). They used to have two, but one of them evolved into an echo chamber to form part of the echolocation system dolphins are so famous for. Macrocephalus means 'big head', and they do have very big heads. The head makes up about 1/3 of the 52 feet of the sperm whale's length and it contains the biggest brain in the world, being 5 times heavier than your brain (if you're an adult human).

'Spermaceti' oil

In French they are called Cachelot (thought to derive from an old French word meaning 'big teeth') and in most major languages they are a variant of either the English or French names, though in Italian they are capodoglio - meaning 'oil head'. This is because their heads are filled with a very fine, strange oil of a quality that no one has been able to replicate and so the oil is still used to today by NASA in lubricating some of their most sensitive instruments. This oil has a very particular appearance such that early whalers believed their heads were filled with semen. They called the oil 'spermaceti' - whale sperm - and the animals were sperm whales. To be absolutely clear - that oil is not, not does it contain, sperm. Its function is not completely clear but there are some ideas about the possible reason for the oil. One is that is may aid in the echolocation functions they use for navigating the dark depths and looking for food. Another possible function is that may help them dive.

Flukes up!

Diving

After cuvier's beaked whale, they are the deepest diving mammals in the world, and whereas most whales dive at an angle, swimming gradually downwards, the sperm whales point their big square heads straight down towards the centre of the earth and plunge vertically, which is why their tails stick out of the water like that. One rather dramatic and very important effect of this vertical diving, and especially of the vertical soaring when they come back to the surface, combined with their vast bulk and prodigiously deep dives, is that they drag up in their wake enormous quantities of nutrients from deep within the pelagic zones off the coastal shelves and contribute hugely to the fecundity of the waters they occupy, giving rise to extremely rich and bio-diverse ecosystems which would not flourish without the activities of these wonderful creatures.

Hard beak of a giant squid

As well as the spermaceti, which was used in making candles, lubricants, lamp oils and other such products, the sperm whale was also highly prized for its ambergris. The diet of the sperm whale consists largely in the giant squid, which it eats whole - beak and all!  

Ambergris from a sperm whale

The beak of the squid is completely indigestible and the whale deals with it by secreting a sort of waxy product from its bile duct, in order to protect its own digestive system from the sharp cutting edges of the broken beak before passing it out the other end. That final product is a rather unpleasant smelling waxy lump called ambergris (from the French meaning ' grey amber'). Over time this product loses its fishy fecal odour and becomes rather sweet smelling and it is worth more than its weight in gold. It is still used as a fixative in the manufacture of perfume. If you ever find a lump of ambergris, keep it safe and sell it to the highest bidder! 

'He's at home'
19th Century - Nantucket

Scrimshaw -
engraved sperm whale tooth

Hunting the sperm whale, while potentially very lucrative, was immensely dangerous and tough work. Ships would be away for years at a time, processing the blubber and spermaceti at sea in far flung corners. The most famous centre for whalers, as immortalised in Herman Melville's Moby Dick, was the island of Nantucket, Massachusetts, just off the coast of New England.

Whale bone canes
Nantucket Whaling Museum

I have visited museums and exhibitions on whales in all sorts of places, but there's nowhere quite like the whaling museum on Nantucket Island, especially if you're interested in sperm whales. In the duller parts of those lonely years away at sea, the crews would often be kept occupied making 'scrimshaw' - the carved and engraved ivory of sperm whales' enormous teeth. Those whalers who had wives back at home in Nantucket would make special gifts from the teeth, adult toys which they called, rather pleasingly, a 'He's at home', to keep their wives entertained during his long absences at sea. Among the amazing collections at that museum is perhaps the world's finest collection of scrimshaw and its worth going all the way to New England for, though if you're in the UK, The Maritime Museum in Kingston-upon-Hull has a wonderful collection of scrimshaw as well.

18 foot sperm whale mandible
Nantucket Whaling Musuem

Moby Dick
by Herman Melville
1851

They are among the most sexually dimorphic of the whales, the males being up to 50% longer and 3 times heavier than females. The average adult grows to around 52 feet, though the there is a jawbone preserved at the Nantucket Whaling Museum, which they claim came from an animal 80 feet long. And the whale which sank the Essex was claimed to have been 85 feet long. The Essex was a Nantucket whaling ship which in 1820, in the middle of the Pacific Ocean, was struck twice and sunk by an apparently angry cachalot. 

1998's Moby Dick

The Heart of the Sea
2015

The story has inspired many writers and artists, including Edgar Allen Poe (in 'The Narrative of Arthur Gordon Pym'), and most famously, Moby Dick, by Herman Melville. The story of the Essex has been rendered for the screen more than once, most notably in 2015's 'The Heart of the Sea', and as well as the dozens of editions of Moby Dick available, that story, once described as 'the greatest work of the imagination in the English language' has also come to the screen on a number of occasions, including the 1956 version with Gregory Peck, and in 1998 with Patrick Stewart as Captain Ahab. I have read and seen all of the above and can heartily recommend all, but don't depart this world without first having read Moby Dick.

Svend Foyn's exploding harpoon

1956's Moby Dick

Nantucket sleigh-ride

It was the huge males, then, which were most sought after, and they were hunted almost out of existence. The population was massively reduced, especially after the introduction of the harpoon gun, which had an explosive head and, once embedded in the whale, would explode, killing the animal almost instantly. They are still in use today by Japanese whaling vessels. Though it sounds brutal and horrific (and it certainly is), this method surely caused far less suffering than the more traditional harpooneers casting spear after spear, being dragged at speeds of up to 23 miles per hour by the terrified animals in what was known as a Nantucket sleigh ride, during which whalers themselves were often killed and the boats smashed. Once the animal was exhausted, the whales would pull themselves alongside and stab the whales to death, which could sometimes take a very long time. After the sleigh-ride, if the boat stayed in one piece, it would often be miles away from the ship and they'd have to spend hours rowing back to the ship towing their catch (if they managed to catch anything) behind them, arriving after dark, themselves exhausted.

As mentioned above, the sperm whale's diet consists largely of giant squid and occasionally colossal squid, which live in the extreme depths of the ocean and so are seldom seen or photographed, though they themselves have frequently caught the imaginations of story-tellers. There are legends of sperm whales being strangled by enormous tentacle, the bones breaking with the noise of cannon blasts. 
The whales often bear scars which would suggest some struggle with oversized prey, but there is no real evidence that any squid ever got the upper hand (or tentacle). They hunt for the squid using echolocation, and the sonic blasts they emit are thought to be powerful enough that they made use them to stun prey. Humans who have swum in close proximity to the whales have talked of feelings of being probed by the powerful clicking and thumping of the echolocation, and in extreme cases, people have been temporarily paralysed, as these clicks are the loudest sound produced by any animal in the world, reaching 230 decibels (a jet engine is around 150 db to give you an idea. There is a good little film about this here.

Sperm whales sleeping