Sperm whales are the ancient marine inhabitants of the Earth. Fossil remains of toothed whales have made it possible to determine the age of their ancestors—twenty-five million years. Sperm whales, close to the modern species in appearance and lifestyle, appeared on our planet 9-10 million years ago.
The sperm whale is a mammal, the largest of all representatives of toothed whales. The animal is considered the largest predator living in the ocean.
Scientific classification
- Kingdom: Animalia (animals)
- Phylum: Chordata
- Class: Mammalia (mammals)
- Order: Cetartiodactyla (cetodactyls)
- Family: Physeteridae (sperm whales)
- Genus : Physeter (sperm whales)
- Species : Physeter macrocephalus (sperm whale)
The name "Physeter" has Greek roots and means "blower". When a sperm whale exhales air from its lungs, a stream of steam is released.
Geographic range
The sperm whale is a cosmopolitan species; it is found in all seas and oceans of the world, although it rarely approaches the polar icy latitudes. Females live in tropical and temperate climates, while adult males can swim in colder waters. Obviously, they are present in the Mediterranean Sea, but cannot live in the Black Sea, since its waters contain large amounts of sulfides (including hydrogen sulfide) and have virtually no oxygen. The presence of sperm whales in the Red Sea has not been confirmed.
Photo: Espaço Talassa
The largest populations inhabit areas located in close proximity to continental shelves. Sperm whales are also occasionally seen near the Gulf of Mexico coastline, where they were once quite common.
Habitat
Sperm whales swim in waters at depths of up to 3,220 meters . This limitation is apparently associated with the time interval required for descent and ascent to the surface. The distribution of these toothed whales varies with season and reproductive/social status, but they are most often found in squid-inhabited waters at depths of at least 1,000 meters. Because sperm whales are so well adapted to deep-sea swimming, they can be in real danger of running aground as they move toward the shoreline.
Feeding features of the sperm whale
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The sperm whale is a predator based on its feeding method and feeds mainly on cephalopods, as well as fish. Of the cephalopods, the whale prefers squid of various types, and to a lesser extent eats octopuses.
The sperm whale catches its food at depths of 300-400 m, and daily it needs about a ton of cephalopods. The animal sucks in the entire prey using its tongue, without chewing it, only tearing very large ones into pieces.
Interestingly, sperm whales often prey on giant cephalopods, for example, huge squids with a body length of more than 10 m and giant octopuses.
Character traits
Appearance
The unique appearance of the sperm whale makes it unmistakable among other cetaceans, and all this is due to its huge (up to 1/3 of the total body length) rectangular head, wide and blunt in front.
Photo: Ganjaa
The S-shaped blowhole is not located in the center, as in the vast majority of cetaceans, but on the left side of the head. The sperm whale has a very thick and wide heart-shaped caudal fin. The animal raises its tail fin high above the water, preparing to dive in search of food. There are many longitudinal grooves in the lower part of the caudal fin. The pectoral fins are small (approximately 200 cm in length) compared to the enormous body size. Instead of a dorsal fin, the sperm whale has a low hump.
The layer of subcutaneous fat of the sperm whale is quite thick, up to 35 cm.
Coloring
Cetaceans usually have smooth, dark-colored skin. However, the sperm whale is an exception - it has highly wrinkled skin of a gray or dark graphite color, which is often compared to a prune. It is noteworthy that males often turn pale with age, and sometimes become piebald. In both sexes, light color is observed in the genital area, anus and lower jaw. There is also evidence of the existence of white sperm whales (albinos).
Big brain and incredible hearing
The sperm whale has the largest brain of any mammal. It can weigh 7.8 kg and have a volume of about 8,000 square centimeters. Therefore, the sperm whale's brain is 5 times heavier than the human brain. Although brain size does affect intelligence (encephalization quotient, EQ), sperm whales are less intelligent than dolphins.
Their olfactory system is poorly developed, which may also indicate a poor state of not only their sense of smell, but also their taste. However, the deficiency of these senses is more than compensated by excellent hearing.
Spermaceti
Photo: Whale Watch Kaikoura
At the top of the whale's skull is a large set of organs filled with liquid substances that harden when exposed to the atmosphere. This substance is called spermaceti. Its function is not fully understood, but scientists believe that the most important task of this fluid and the entire organ system that produces it is the generation of powerful, concentrated sound signals used in echolocation and communication.
The spermaceti-producing organ, the melon, also regulates the buoyancy of the toothed whale. Changing the state of the liquid helps the sperm whale make long dives.
History of origin
According to the theory, more than 70–75 million years ago, the ancestors of modern sperm whales lived on land. Their body was covered with fur, and instead of today's fins, they had ordinary limbs. Gradually, the animals moved closer to the water , where they escaped from a large number of predators and other animals. Then they finally moved into the water, where they changed in size, got rid of their fur and became similar to modern whales.
In connection with active fighter activity in the 18th–19th centuries. whales became an endangered species, and soon a moratorium on their hunting was introduced, preventing them from being caught for any purpose. However, they are still at risk from being hit by passing ships, being contaminated by oil refineries, or being washed ashore.
Dimensions
The length of a sperm whale can reach 16-19 meters . The largest specimen discovered was 20.5 meters long. These data refer to sexually mature male sperm whales. Females are about a third smaller, their length usually does not exceed 13 meters. Newborns are usually around 4 meters in size.
Males can weigh 41 tons (the heaviest individuals gain up to 75 tons in weight), females - 14 tons. The body weight of newborns is approximately 1/25 that of females.
Male and female sperm whale: main differences
Sexual dimorphism in the sperm whale is clearly manifested in the fact that females are two times smaller than males. Considering the gigantic size of the mammal, this difference is striking: the maximum body length for males is 20 m, for females - 15 m, maximum weight - 50 and 15 tons, respectively.
Vocalizations
When using an echolocation system, the sperm whale emits broadband sound signals in a specific direction by exhaling air through its sonic lips located in the front of the nose, below the nasal opening. The sounds move backward along the nose through the melon. Most of the signal is reflected in the frontal sac located on the whale's skull, focusing the sound. Subsequently, the sound passes through the melon again, returning to the nose area. The entire process takes just a few milliseconds.
By analyzing the sound emitted by a sperm whale, researchers can estimate the size of its melon. Each whale has its own unique "tone". It changes as the melon matures and grows. The spermaceti-filled canal transmits sounds to the inner ear. The air inside the sperm whale's head is constantly fluctuating, which is why it produces sounds while underwater. There are 4 types of sounds:
- normal click;
- squeal;
- "knock";
- wheezing
Photo: CGTN
Each whale also produces a stereotypical, repeating sequence of 3-40 or more clicks when encountering another sperm whale.
The sperm whale is the loudest animal on Earth. It can produce sounds with an intensity of 230 decibels (dB). For comparison: a launch jet is 140 dB, a nuclear explosion is about 220 dB. The voices of sperm whales can be heard many kilometers away using underwater listening devices.
Diving
Besides the northern bottlenose (Hyperoodon) and southern elephant seal (Mirounga), the sperm whale is the deepest diver of all marine mammals. It can dive to a depth of three kilometers and remain at a depth of up to 90 minutes. However, the sperm whale usually dives to a depth of 400 meters and spends about 35 minutes underwater.
This giant cetacean is adept at adapting to the sudden changes in pressure during a dive, thanks to its elastic chest, which allows its lungs to “compress”, slowing its metabolism and conserving oxygen. Between deep dives, the sperm whale takes 8-minute breaks to take 20-70 breaths above the surface of the water.
Photo: Whale Express
Sperm whales usually swim at a speed of no more than 10 km/h, but if disturbed they can reach speeds of up to 30 km/h .
Sperm whale distribution
The sperm whale's habitat is one of the largest animals in the world. It lives throughout the entire World Ocean, excluding the coldest northern and southern regions, and prefers warmer, tropical waters. Whales live far from the coast, at depths of more than 200 m, where there are many large cephalopods - the basis of their diet. Seasonal migrations are pronounced, especially among males.
Social structure
Sperm whales migrate and remain associated with the same groups over many years. It is extremely rare for other individuals to join a fixed group or for "old" members to leave it. One group usually consists of 6-9 individuals, although groups of more than 20 toothed whales can be observed.
Groups often consist of bachelor males (sexually inactive males) or sexually mature females and their immature offspring of both sexes. Adult males lead a solitary lifestyle, except during the breeding season. The older the male, the more willing he is to live alone.
Related sperm whales do not copulate, as killer whales often do. Females and young animals spend 3/4 of their lives hunting, devoting the rest of their time to social interaction. Social "rituals" usually take place in the afternoon.
Natural enemies
Although nature has endowed the sperm whale with a formidable appearance, it still has enemies - killer whales. They attack in groups mainly females and cubs. But if male sperm whales receive a signal of an attack, they rush to the defense of their relatives and most often deprive the killer whales of their prey.
The killer whale is the enemy of the sperm whale
Harm to the health of the sperm whale can be caused by: endoparasites, copepods (panella), and barnacles.
Eating habits
The sperm whale's diving habit is related to its diet - it preys on two types of squid: giant squid (Architeuthis dux) and colossal squid (Mesonychoteuthis hamiltoni). At the same time, these are the two largest mollusks in the world. The giant squid can weigh up to 500 kg and grow up to 10 meters. The colossal squid reaches 13 meters in length and 275 kg in weight.
Photo: www.rside.org
In addition, sperm whales hunt:
- octopuses;
- deep sea fish;
- sharks;
- seahorses.
Sperm whales consume about 3% of their body weight per day. Their esophagus is the largest among cetaceans; in fact, it is the only esophagus large enough to swallow a person.
The jaw of sperm whales is long and narrow. There are 18-26 teeth on each side of the lower jaw, but the upper teeth are few, weak and non-functional. The lower cone-shaped teeth fit perfectly into the sockets of the upper jaw.
Photo: Klaus Rudloff
However, it has been proven that the sperm whale copes well with hunting even without teeth. Apparently, fighting between males is a more likely reason for the existence of such teeth. Older individuals have numerous scars reminiscent of sperm whale bites.
Season of reproduction and development of young
During the breeding season, breeding “harems” are formed, consisting of 1-5 large males and a mixed group of females and males of different ages. During this period, there is fierce competition between males for females. Only about 10-25% of sexually mature males in a population are capable of reproduction.
The mating process is still not fully understood. There is evidence of a male hierarchy, but it is unclear whether the female can choose a mate, as humpback whales do. After birth, males show no interest in offspring.
Gestation lasts from 15 to 18 months, resulting in the birth of one calf. Females give birth several years apart. Lactation lasts from 9 to 13 months, but young animals can suckle at their mother’s breast for up to two years.
Females mature at 8-11 years of age, and males become sexually mature at about 10 years of age, although males often do not begin mating until they are 25-27 years old because they do not have a high enough social status until then. After reaching maturity, males migrate to areas of higher latitudes, where the water is colder and hunting is more efficient.
- Mating system: polygamy (promiscuity)
- Average age of sexual or reproductive maturity: 9 years (females), 10 years (males)
- Breeding interval: every two to five years
- Breeding season: Peak mating season occurs in spring in both the Northern and Southern Hemispheres
- Average number of offspring: one cub
- Average gestational age: 16.5 months
Fight for life
During an attack by a whaling ship on a sperm whale, the latter became enraged, and as a result, the sperm whale very often sank the ship. There is historical evidence of ships sunk by sperm whales. In 1851, a wounded sperm whale, having rushed at one whale boat and smashed it to pieces, rushed to another, but his attention was immediately diverted by a third.
The latter managed to escape from him with difficulty, and then he rushed towards the main whaling ship, which was approaching him in full sail. The ship, however, managed to evade the animal with a quick turn, which immediately afterwards fell in its death throes and could not repeat the attack. Another ship had it worse.
In 1820, in the South Pacific Ocean, one ship was attacked by an angry sperm whale, which, with the first of two well-aimed blows, caused a strong hole in the ship, and with the second, broke the bow, after which the ship sank. In a similar way, a ship was lost off the coast of Peru in 1851. There is an assumption that many of the disappeared ships owe their death to sperm whales.
Interspecies relationships
The sperm whale has several enemies. In addition to humans, they are preyed upon by killer whales (Orcinus orca) and black killer whales (Pseudorca crassidens). The most vulnerable targets for attack are young sperm whales. Killer whales do everything to separate the calf from its group. The group protects a young or wounded individual by surrounding it with its tails facing outward. Outwardly, such a figure resembles a daisy , which is why it received the name “daisy formation.” The sperm whale's tail fin becomes a deadly weapon. One blow is enough to kill an orca.
Photo: VCG Photo
It is unknown whether sperm whales form friendly relationships with other cetacean species, but a common bottlenose dolphin with a spinal deformity has been seen as part of a group of sperm whales.
Meaning to people
In past centuries, sperm whales have been the target of commercial whaling, especially in areas around the Gulf of Mexico. Their meat is usually not eaten. Instead, spermaceti is extracted from the head and the teeth are often used as the basis for artistic engraving and carving known as scrimshaw.
The head of a sperm whale contains 3-4 tons of spermaceti, a substance valued as a lubricant for precision mechanisms and automatic transmissions. It is also used to make ointments and thin, smokeless candles (where it hardens into white wax when exposed to air).
Photo: Wikipedia
However, the most important product obtained from sperm whales is oil, which was once used as fuel for lamps and is now used as a base for skin creams and cosmetics.
Sperm whales produce a resinous substance called ambergris . It is a product of the whale's digestive system, the result of indigestion or constipation. Ambergris was once believed to have healing properties, but is now widely used in the perfume industry. When exposed to air, the ambergris hardens and acquires a sweet, earthy odor reminiscent of horse sweat with a “marine” undertone.
On the other hand, being fiercely aggressive, male sperm whales posed a threat to whalers in the 19th century, especially in small boats. Now they cannot resist ships with modern whaling equipment.
Save Status
Sperm whales were once quite abundant in the Gulf of Mexico, but due to commercial whaling operations they are now rarely seen in the area. However, worldwide, sperm whale populations are more stable than many other whale species, although they are still listed as endangered, where they were listed in 1980.
The sperm whale is currently the most abundant of the great whales and is hunted with less intensity than baleen whales. There are approximately 1,500,000 sperm whales worldwide.
Population today
For a long time, sperm whales were destroyed by people. As a result, there was a threat of complete extermination of this animal species. Therefore, since 1985, a law was introduced banning sperm whale fishing. Currently, only Japan has permission to allow limited harvest of sperm whales for scientific purposes and research.
The measures taken made it possible to preserve the population. There are no exact figures on the number of sperm whales in nature. But the population of sperm whales is considered vulnerable, since the increase in animals is negligible. The reason is the long cycle of reproduction of offspring.
Did you know?
- Like other cetaceans, sperm whale milk is very fatty (36%), comparable in consistency to cottage cheese, making it easily consumed underwater.
- Cubs can suckle milk from other females, not just their mothers.
- It has been confirmed that sperm whales can suffer from decompression sickness; a rapid ascent to the surface is often fatal.
- Due to the asymmetrical shape of the skull, the sperm whale uses echolocation very effectively because it receives signals from both sides slightly differently.
- The sperm whale has the longest intestine in the world.
- A melon can contain up to 1,900 liters of spermaceti.
- During very deep dives, sperm whales often become entangled in telecommunications cables and drown.
- A sperm whale tooth can weigh up to a kilogram.
