Scientific Name: Physeter macrocephalus
Family Name: Physeteridae
Trophic Level: Carnivore
Life Span: Sperm whales can live 70 years or more.
Description: The sperm whale is the largest toothed whale, with adult males measuring up to 20.7 metres (68 ft) long and weighing up to 80 tonnes. The sperm whale is among the most sexually dimorphic of all cetaceans. At birth both sexes are about the same size, but mature males are typically 30% to 50% longer and three times as massive as females. Male sperm whales are physically mature at about 16 metres meters (12 to 14 ft) long in length. The sperm whale's flukes (tail lobes)
are triangular and very thick. Proportionally, they are larger than that of any other cetacean, and are very flexible. The sperm whale respiratory system has adapted to cope with drastic pressure changes when diving. The flexible ribcage allows lung collapse, reducing nitrogen intake, and metabolism can decrease to conserve oxygen. Between dives, the sperm whale surfaces to breathe for about eight minutes before diving again.Height: Adult males measuring up to 20.7 metres (68 ft) long. Females grow up to 11 metres (36ft).
New-born sperm whales are the height of 4 metres
Weight: Adult males weigh up to 80 tonnes.
Females weigh up to 14 tonnes.
New born weigh 1 tonne.
Diet: They feed on several species, notably the giant squid, but
also the colossal squid, octopuses, and fish such
as demersal rays, but their diet is mainly medium-
sized squid. Some prey may be taken accidentally while eating other items. Threats: The introduction of plastic waste to the ocean environment by humans is relatively new. From the 1970s, sperm whales have occasionally been found with pieces of plastic in their stomachs.
Global Population: 1.1 million individuals with numbers
declining to roughly 360,000 by the year 1999.
- The sperm whale is a pelagic mammal with a worldwide range, and will migrate seasonally for feeding and breeding.
- Other name for sperm whale is cachalot.
- Sperm whales have the largest brain on Earth, more than
five times heavier than a human's. - The sperm whale brain weigh about 7.8 kg.
- The lower jaw sperm whale is long and narrow.
- The sperm whale has 18 to 26 teeth on each side of its lower
jaw which fit into the sockets in the upper jaw.
- The teeth are cone shaped and weigh up to 1kg.
- The teeth are functional, but do not appear necessary for capturing or eating squid.
- Analysing the teeth is the preferred method for determining the age of a sperm whale.
- Like the age-rings in a tree, the sperm whale’s teeth build distinct layers of cementum and dentine as they grow.
- The sperm whale’s cerebrum is the largest in all Mammalia, both in absolute and relative terms.
- The olfactory system is reduced, suggesting that the sperm whale has a poor sense of taste and smell.
- The auditory system is enlarged.
- The pyramidal tract is poorly developed, reflecting the reduction of its limbs.
- The sperm whale has a flexible ribcage which allows lung collapse to reduce nitrogen intake and metabolism can decrease to conserve oxygen.
- The sperm whale comes to the surface and breathes for about eight minutes before it dives.
- The sperm whale has the longest intestinal system in the world.
- The sperm whale has four-chambered stomach like the ruminants.
- Since whales cannot chew their food, the first chamber has very thick muscular walls to crush the food and also does not secrete gastric juices.
- The first chamber also withstands the attacks of the claw and sucker of the swallowed squid.
- The second chamber is large and the digestion starts here.
- The squid beaks which are undigested gets accumulated in the second chamber.
- Most squid beaks are vomited by the sperm whales.
- Myoglobin, which stores oxygen in the muscle tissue, is plentiful than in other terrestrial animals.
- The blood has a high density of red blood cells, which contain oxygen-carrying haemoglobin.
- The spermaceti organ may also play a role by
adjusting buoyancy.
- The arterial retia mirabilia are extraordinarily well-developed.
- The complex arterial retia mirabilia of the sperm whale are more extensive and larger than those of any other cetacean.
- Atop, the whale’s skull is arranged a large complex of organs filled with a liquid mixture of fats and waxes called spermaceti.
- The purpose of this complex is to generate a powerful and
focused clicking sound, which the sperm whale uses for its echolocation and communication. - The spermaceti organ is like a large barrel of spermaceti.
- Its surrounding wall (known as the case) is extremely tough and fibrous.
- This case can hold 1,900 litres of spermaceti.
- This case is larger in males.
- The spermaceti oil is a mixture of triglycerides and wax ester.
- Below the spermaceti organ lies the “junk” which consists of compartments of spermaceti separated by cartilage.
- It is similar to the melon found in toothed whales.
- The sperm whales eyes is the largest among the toothed whales, weighing about 170g.
- The cornea is elliptical and the lens is spherical.
- The sclera is very hard and thick.
- There are no ciliary muscles.
- The choroid is very thick and contains a fibrous tapetum lucidum.
- The sperm whale’s eyes afford good vision and sensitivity to light.
- Sperm whales use vision to hunt squids.
- It does it either by detecting the squids silhouettes or by detecting squid’s bioluminescence.
- Sperm whales have 21 pairs of chromosome.
- The sperm whale is the loudest animal in the world.
- When echolocating, the sperm whale emits a directionally focused beam of broadband clicks.
- Clicks are generated by forcing air through a pair of phonic lips (also known as “monkey lips”or “museau de singe”) at the front end of the nose, just below the blowhole.
- An individual whale’s clicks is unique.
- If a whale gets mature, its spermaceti organ increases, in which, the tone of the whale’s click will also change.
- The lower jaw is the primary reception path for echoes.
- There are many types of vocalisation in sperm whales which they use it for many things.
- Sperm whales are among the most cosmopolitan species.
- They prefer ice-free water over 1,000 metres (3,300 ft) deep.
- Sperm whales have been considered to be locally extinct along the coastal waters of southern Australia.
- Sperm whales usually dive between 300 to 800m (980-2,620 ft) and 1 to 2 km (3,300-6,600 ft), in search of food.
- Dives like this can last up to one hour.
- Battles between sperm whales and squids have never been observed by humans, but the white scars are believed to be caused by large squids.
- Once in study, it showed that female sperm whales may collaborate when hunting Humboldt squids.
- The sharp beak of a squid which is consumed lodged in the whale’s intestine may lead to the production of ambergris, similar to the pearls in an oyster.
- The irritation of the intestines caused by the squid beaks stimulates the secretion of this lubricant-like substance.
- Sperm whales hunt through echolocation.
- There clicks are the loudest in the animal kingdom.
- It has been hypothesised so that it can stun its prey by clicks.
- Bulls fight with each other for females, and males mate with multiple females, making them polygynous.
- Bulls do not provide parental care to their offspring, but, play a fatherly role to younger bulls to show their dominance.
- Females became fertile at the around the age of 9yrs.
- The oldest pregnant female ever recorded was 41yrs old.
- Gestation period requires 14-16 months, to produce a single calf.
- Sexually mature females give birth once in 4-20 years.
- Birth is a social event, where the mother and the calf need others to protect them from predators
- The other adults of the pod, may bump and bite the new- born in its first hour.
- Sperm whale’s milk has higher fat content than that of the terrestrial mammals.
- Males become sexually mature at the age of 18yrs.
- Upon reaching sexual maturity, males move to the higher latitudes, whereas, the females remain at lower latitudes.
- Males reach their full size at the age of 50.
- Females and young males live together in groups, while mature males (bulls) live solitary lives outside of the mating season.
- The females cooperate to protect and nurse their young.
- Females give birth every four to twenty years, and care for the calves for more than a decade.
- A mature sperm whale has few natural predators, although calves and weakened adults are sometimes killed by pods of killer whales (orcas).
- Females and their young ones live in matriarchal groups called pods, while the bulls apart, like the elephants.
- Females and the calves spend about three-quarters of their time foraging and a quarter of their time socializing.
- Socializing usually takes place in the afternoon.
- When sperm whales socialize, they emit complex clicks known as the codas.
- They spend much of the time rubbing against each other.
- The groups engage in herding of prey, similar to bait balls created by other species
- The most common natural predator of sperm whales is the killer whale, but pilot whales and false killer whales sometimes harass them.
- Killer whales prey on target groups of females with young, usually making an effort to extract and kill a calf.
- The females will protect their calves or an injured adult by
encircling them. - They may face inwards with their tails out (the 'marguerite formation', named after the flower ‘marguerite’).
- If the killer whale pod is large, its members may sometimes be able to kill adult female sperm whales and can at least injure an entire pod of sperm whales.
- Bulls have no predators, and are believed to be large, powerful and aggressive to be threatened by killer whales.
- Sperm whales are not known for forging bonds with other species, but it was observed that a bottlenose dolphin with a spinal deformity had been accepted into a pod of sperm whales.
- They are known to swim alongside other cetaceans such as humpback, fin, minke, pilot, and killer whales on occasion.
- Sperm whales can suffer from parasites.
- Out of 35 sperm whales caught during 1976-1977 Antarctic whaling season, all of them were infected by Anisakis physeteris (in their stomach) and Phyllo bothrium delphini (in the blubber).
- Whales with a placenta were infected with Placentonema gigantissima, the largest nematode worm.
- Spermaceti, obtained primarily from the spermaceti organ, and sperm oil, obtained primarily from the blubber in the body, were much sought after by 18th, 19th, and 20th century whalers.
- These substances found a variety of commercial applications, such as candles, soap, cosmetics, machine oil, other specialised lubricants, lamp oil, pencils, crayons, leather waterproofing, rust-proofing materials and many pharmaceutical compounds.
- Ambergris, a solid, waxy, flammable substance produced in the digestive system of sperm whales, was also sought as a fixative in perfumery.
- The biggest threats to the sperm whales population are the entanglement in fishing nets and collisions with ships.
- Other threats include ingestion of marine debris, ocean noise, and chemical pollution.
- Rope-mounted teeth are important cultural objects throughout the Pacific.
- Whale ivory and bone were taken from beached whales.
- In Fiji, the teeth are known as tabua, traditionally given as gift for atonement and were important in negotiations between rival chiefs.
- In Fiji, whale’s teeth were the most-demanded article of ornament and value.
- They often occurred in necklaces.
- The tabua remains an important item in Fiji.
- The teeth were originally rare in Fiji and Tonga, which exported teeth, but with the Europeans' arrival, teeth flooded the market and this "currency" collapsed.
- The oversupply led in turn to the development of the European art of scrimshaw.
- Sperm whales are not the easiest to watch, due to their long dive times and ability to travel long distance underwater.
- Sperm whale watchers use hydrophones to listen to the clicks of the whales and locate them before they surface.
- The introduction of plastic waste to the ocean environment by humans is new.
- From the 1970’s, sperm whales have occasionally been found with pieces of plastic in their stomach.
Meanings
- The pyramidal tract – The pyramidal tract provides voluntary control of muscular movements.
- Cornea – The cornea is the transparent front part of
the eye that covers the iris, pupil, and anterior chamber. - Sclera – The sclera, also known as the white of the eye
- Choroid – the choroid is a vascular layer of the eye containing connective tissues and lying between the retina and the sclera.
- Chromosome – A chromosome is a long DNA molecule with part or all of the genetic material of an organism.
- Blubber – Blubber is a thick layer of vascularised adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians.
- Scrimshaw – Scrimshaw is scrollwork, engravings, and carvings done in bone or ivory. Typically it refers to the artwork created by whalers, engraved on the by-products of
whales, such as bones or cartilage. - Hydrophones – A hydrophone is a microphone designed to be used underwater for recording or listening to sounds underwater.