Marine Creature of the Month Jan '20
Marine Creature of the Month
Famous Fish
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| Sally & Samson (1985, Hastrup) Photo found on Tumblr |
Sally & Samson
Sperm Whales
Say hello to my very niche childhood. This is a Danish animated film from the 80s, based on a Danish novel. It is super rare nowadays because limited VHS copies were released originally and it never got a DVD outside of Europe. I don't really remember much of this film, having not seen it for probably twenty years, but it is harrowing! And on point with marine pollution. Clearly, this is something that has been with me all my life whether I knew it or not! If you can find any non-Danish clips, I highly recommend the Walrus song.
Kingdom: Animalia
Class: Mammalia
Conservation Status: Vulnerable
WHAT ARE SALLY AND SAMSON?
They are sperm whales which are the largest toothed whales alive currently. Other notable famous sperm whales are, of course, Moby Dick and Monstro from Pinocchio. Why was Moby Dick not the famous fish of choice? Despite actually being in this film, he was not a strong feature of my childhood. I have also never read the book. (I know, shock horror!) But back to sperm whales rather than my questionable consumption of popular culture.
As well as being the largest toothed whale, sperm whales are the largest toothed predator alive. The larger males grow, on average, to 16m (52ft) but have been known to grow as large as 20.7m (68ft). They can weigh up to 50 tonnes and come in a variety of colours from dark grey to light brown. White whales, or albino whales, are rare. Their skin is also wrinkled, a trait unique to their species.
WHAT DO SPERM WHALES LOOK LIKE?
Sperm whales have an iconic look which no other whale possesses. Rather than the pointed head, they have a large, box-y head with a blunt snout. This is due to a large organ residing in their heads which is filled with spermaceti - a wax-like substance from which the sperm whale gets its name. Despite having such a large head, sperm whale mouths are relatively small. They are narrow and only open on the underside of their heads. Their mouths are lined with large teeth weigh 1kg (2.2lbs) each, are conical in shape, and are up to 20cm (8in) long. It is believed they are used less for hunting and eating and more for aggression between mature males. Older males often sport heavy scaring which supports this theory.
Instead of a dorsal fin, the one along the spine, they have a hump. It is a small, rounded triangle on the lower half of their back and there are smaller "knuckles" leading to their tail. They are usually uniform in colour but some do have coloured patches - like Sally. The flukes on their tail - the fan-like part - are broad and useful for propelling themselves towards great depths.
WHERE DO THEY LIVE?
Sperm whales are pelagic creatures, meaning they spend most of their lives in deep waters. They are spread across the world but are often found in concentrated patches. They are rarely found offshore. They only times they venture towards land is if the waters are still more than 200m (655ft) deep. While not common, some have been found in more polar regions in summer months, especially older males. Winter months are spent in more tropical and temperate waters. Populations tend to be denser around continental shelves and canyons.
Sperm whales like deep waters. Deeeeeep waters. Waters as deep as 1,000m (3,300ft), and preferably ice free. They are known for diving great depths in the pursuit of food and it is believed their spermaceti helps them do so. It is used as a buoyancy aid. The theory is that sperm whales take on cold water before diving which cools the entire whale - spermaceti included. This causes it to solidify and increase in density, which allows the whale to dive with more ease. However, more recent research has called this theory into question.
HOW DO THEY LIVE?
WHAT DO SPERM WHALES LOOK LIKE?
Sperm whales have an iconic look which no other whale possesses. Rather than the pointed head, they have a large, box-y head with a blunt snout. This is due to a large organ residing in their heads which is filled with spermaceti - a wax-like substance from which the sperm whale gets its name. Despite having such a large head, sperm whale mouths are relatively small. They are narrow and only open on the underside of their heads. Their mouths are lined with large teeth weigh 1kg (2.2lbs) each, are conical in shape, and are up to 20cm (8in) long. It is believed they are used less for hunting and eating and more for aggression between mature males. Older males often sport heavy scaring which supports this theory.
Instead of a dorsal fin, the one along the spine, they have a hump. It is a small, rounded triangle on the lower half of their back and there are smaller "knuckles" leading to their tail. They are usually uniform in colour but some do have coloured patches - like Sally. The flukes on their tail - the fan-like part - are broad and useful for propelling themselves towards great depths.
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| Photo from ThoughtCo |
WHERE DO THEY LIVE?
Sperm whales are pelagic creatures, meaning they spend most of their lives in deep waters. They are spread across the world but are often found in concentrated patches. They are rarely found offshore. They only times they venture towards land is if the waters are still more than 200m (655ft) deep. While not common, some have been found in more polar regions in summer months, especially older males. Winter months are spent in more tropical and temperate waters. Populations tend to be denser around continental shelves and canyons.
Sperm whales like deep waters. Deeeeeep waters. Waters as deep as 1,000m (3,300ft), and preferably ice free. They are known for diving great depths in the pursuit of food and it is believed their spermaceti helps them do so. It is used as a buoyancy aid. The theory is that sperm whales take on cold water before diving which cools the entire whale - spermaceti included. This causes it to solidify and increase in density, which allows the whale to dive with more ease. However, more recent research has called this theory into question.
HOW DO THEY LIVE?
Like other cetaceans, sperm whales live in pods usually averaging in fifty whales. The mature males live in solitary but the females and calves live in social groups. The males rejoin the pods during the mating season. They can live up to seventy years in the wild and females reach maturity around nine years old, with males lagging behind at eighteen. Mature females give birth every four to twenty years after gestating for 14-16 months. Birth is a social event for the sperm whales, the females of the pod will protect the birthing mother from predators during labour and jostle the newborn in its first few hours of life.
The males will fight for the females and often breed with more than one, making them polygynous. Once the deed is done, however, the males resume their solitary life and take no care of their offspring. That is up to the mothers and other ladies of the pod. It has even been witnessed that calves will feed from whales other than their own mother. The significant parental aid has been attributed to the longevity of the species - human impacts aside.
It is believed that sperm whales eat squid, among a few other things. Their dinner is the reason why they dive so deep. They hunt at depth, diving for roughly an hour at a time, searching for various species of squid to munch on. With there being low light at great depth, they have relatively good eyesight, despite having such small eyes. It is believed they use them to detect the silhouettes of squid or bioluminescence on deep-dwelling critters. They can also use echolocation and even have an asymmetrical skull to help them determine the direction of sounds.
The males will fight for the females and often breed with more than one, making them polygynous. Once the deed is done, however, the males resume their solitary life and take no care of their offspring. That is up to the mothers and other ladies of the pod. It has even been witnessed that calves will feed from whales other than their own mother. The significant parental aid has been attributed to the longevity of the species - human impacts aside.
It is believed that sperm whales eat squid, among a few other things. Their dinner is the reason why they dive so deep. They hunt at depth, diving for roughly an hour at a time, searching for various species of squid to munch on. With there being low light at great depth, they have relatively good eyesight, despite having such small eyes. It is believed they use them to detect the silhouettes of squid or bioluminescence on deep-dwelling critters. They can also use echolocation and even have an asymmetrical skull to help them determine the direction of sounds.
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| Photo from National Maritime Historical Society |
WHAT THREATENS SPERM WHALES?
As mature adults, they have few predators thanks to their size. Weak adults and calves are vulnerable to predators like orcas - and we all know that they are opportunistic hunters! Once again, it seems the main threat to sperm whales are humans. Namely, whalers. Spermaceti was a highly sought after product in Victorian times. It was used for everything - oil, lubricant, candles. Whale bones were also used in fashion, as structural support in corsets. They also produce ambergris which is used in perfumes as well as other products. Sperm whales were the primary target of whalers for a long time.
They have also been hunted for their teeth, due to their similarity to ivory. Whalers would take the teeth and produce inked carvings called scrimshaw. They would be hollow on one half and often depict naval scenes. The art was widely practised but declined after the retirement of whaling fleets in the 1880s. It is now illegal to sell or trade scrimshaws which have been made post-1973 thanks to the sperm whales having become a protected species. So at least there is that.
Because of their extensive exploitation and slow maturity, sperm whales have been unable to reproduce quick enough to regain their numbers. They are now a protected species but the damage has been done. It is believed that sperm whales were larger in the past but extensive whaling of the larger males has caused a decrease in size. This is common throughout over-fished populations across the world, not just in whales.
As mature adults, they have few predators thanks to their size. Weak adults and calves are vulnerable to predators like orcas - and we all know that they are opportunistic hunters! Once again, it seems the main threat to sperm whales are humans. Namely, whalers. Spermaceti was a highly sought after product in Victorian times. It was used for everything - oil, lubricant, candles. Whale bones were also used in fashion, as structural support in corsets. They also produce ambergris which is used in perfumes as well as other products. Sperm whales were the primary target of whalers for a long time.
They have also been hunted for their teeth, due to their similarity to ivory. Whalers would take the teeth and produce inked carvings called scrimshaw. They would be hollow on one half and often depict naval scenes. The art was widely practised but declined after the retirement of whaling fleets in the 1880s. It is now illegal to sell or trade scrimshaws which have been made post-1973 thanks to the sperm whales having become a protected species. So at least there is that.
Because of their extensive exploitation and slow maturity, sperm whales have been unable to reproduce quick enough to regain their numbers. They are now a protected species but the damage has been done. It is believed that sperm whales were larger in the past but extensive whaling of the larger males has caused a decrease in size. This is common throughout over-fished populations across the world, not just in whales.
Being quite aggressive, sperm whales do fight back and have even caused ships to sink. This was the inspiration for Moby Dick after all. So, yay on getting their revenge? Although it is a double-edged sword as any "aggressive" animal then becomes a target for sport hunting. Gosh, people are the worst sometimes.
Mainly, nowadays, they are at the same risk as the rest of the ocean: plastic pollution, dead zones created by over fertilisation, diminishing food stocks, and reduced habitats.
Mainly, nowadays, they are at the same risk as the rest of the ocean: plastic pollution, dead zones created by over fertilisation, diminishing food stocks, and reduced habitats.
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| That is a plastic bucket stuck in a calf's mouth. Photo from Radio Times |
FUN FACTS
- A sperm whale's head makes up a third of its length, making it the largest head in the animal kingdom.
- They are the second deepest diving mammal - second to Cuvier's Beaked Whale.
- They have the largest brain on the planet, five times heavier than humans!
- The sperm whale is one of the most exploited whales in the ocean.
- Male sperm whales can be as much as 50% bigger than females.
- Despite being designed to dive, they still suffer from decompression sickness like human scuba divers.
- The age of a sperm whale can be determined by its teeth.
- The oldest recorded pregnant sperm whale was 41 years old.
Which is your favourite whale? Would you like to see Sally & Samson? Which famous fish would you like me to look at next? Lemme know below!
Listening to: Guilty Pleasures
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