17 facts about Rice's whale
Rice’s whale was not considered a species until 2021. Even now it is commonly mistaken for Bryde’s whale, with only genetics and anatomy distinguishin ...
In the depths of the oceans, where sunlight loses its meaning, reigns one of the most majestic and enigmatic inhabitants of the seas–the spermaceti sperm whale (Physeter macrocephalus).
This giant marine mammal, capable of plunging to depths of more than two kilometers, is not only a master of swimming in the abysses of the sea but also a carrier of one of nature’s most mysterious substances–spermaceti. It is spermaceti that is credited with the sperm whale’s ability to adapt to the harsh marine environment.
Human history is intertwined with the history of spermaceti. The unique properties of spermaceti made it a valuable commodity for humans, and the demand for it was associated with bloody hunts for these mammals, resulting in a drastic reduction in their population. Today, the threat to spermaceti is human activity associated with climate change and environmental degradation.
Copyright: Image from Australian Museum
Sperm whales are classified into Odontoceti within the clade Cetacea. The common name for some mammals of the order Cetacea of larger size (including sperm whales) is whales.
The sperm whales include one contemporaneous genus–the Physeter sperm whale–whose representative is the spermaceti.
This was done by Swedish naturalist Charles Linnae in his landmark 10th edition of Systema Naturae, and he gave it the name Physeter macrocephalus. The species is considered by some to be monotypic–geographically undifferentiated, with its populations not differing from one another despite being a considerable distance apart.
They are found in all oceans. Males in particular, which are known for their long-distance migrations, venture into the polar regions and marginal seas, while females, along with their young, concentrate in the tropics and subtropics and avoid surface temperatures below 15 degrees Celsius.
In August 2004, a sperm whale was observed in the Baltic Sea. However, the Baltic is too shallow for the sperm whale, which dives to great depths and does not provide it with adequate food. Sperm whales can be found year-round in the Azores, off the coast of Portugal, as well as in the Mediterranean Sea, in the Greek coastal area (population of about 200 animals).
In sperm whales, there is the greatest sexual dimorphism in terms of length and weight among all cetaceans. Both sexes are about the same size at birth (3.7 to 4.3 meters long), but mature males are typically 30 to 50 percent longer and three times as massive as females.
Typical values in this regard for females are 1100 centimeters and 15.000 kilograms and for males, 1500 centimeters and 45.000 kilograms.
Female sperm whales reach physical maturity at about 10.6 to 11 meters in length and generally do not reach more than 12 meters in length. The largest female sperm whale measured 12.3 meters in length. Males reach physical maturity at 15-16 meters in length, and larger males can reach 18-19 meters. There are reports of individual sperm whales reaching even greater lengths, with some historical reports even claiming a length of 24 meters.
It is almost rectangular, widened at the end of the snout, and steeply truncated. On the left side of the front of the head is an S-shaped ejaculatory opening, giving a distinctive bushy forward-facing jet.
The eyes of the sperm whale do not differ much from those of other tooth fish, only–the eye of the sperm whale weighs about 170 grams and is shaped like an ellipsoid. Like other pinnipeds, the sperm whale can retract and extend its eyes thanks to a retractor muscle but is unable to rotate the eyes in the eye sockets. Its eyes provide it with good vision and light sensitivity.
It is the largest known brain of any modern or extinct animal, weighs on average about 7-8 kilograms, and has a volume of about 8000 cubic centimeters.
It is a semi-liquid substance consisting mainly of palmitoyl esters and cetyl alcohol, produced in a spermaceti organ inside the sperm whale’s head. This organ can contain up to 1900 liters of spermaceti. The spermaceti retains its semi-liquid consistency only at the whale’s body temperature and solidifies upon contact with air temperature.
Up to two tons of spermaceti can be obtained from the body of a large individual, which can be used to make candles, ointments, creams, medicines, crayons, and ink. In the 19th and early 20th centuries, spermaceti was the best machine lubricant. Today is it used in the pharmaceutical industry.
Spermaceti is one of the substances extracted by whalers.
Ambergris is a secretion from the sperm whale’s digestive tract, which is produced by indigestion or constipation. It appears in the whale’s feeding area, where it floats on the surface of the water in the form of lumps and is later thrown onto the ocean shore. Such lumps have different sizes and forms, their weight is 1-20 kilograms. Ambergris has the consistency of gray, yellow or brown wax, is lighter than water, softens at the temperature of the human body, and liquefies at the boiling point of water. It is one of the few natural raw materials of the perfume industry of animal origin. It is used by the most reputable perfume manufacturers.
Today, due to the protection of sperm whales, natural ambergris is not available. Its synthetic, or plant-based (products obtained from hibiscus seeds) substitutes are used.
They are located in the mandible, and there are vestigial teeth in the jaw, which are covered with gums. The teeth of sperm whales were once used by whalers to carve into them–these were known as scrimshaw. These carvings were created during long expeditions on whaling ships, and usually depicted genre scenes, landscapes, or scenes from the lives of sailors. They became popular as fireplace sculptures and are still highly regarded by collectors today.
Today, the technique used by sailors is used to decorate objects made of bone or antler, popular for decorating knife handles.
The pectoral fins are small, and the caudal fin is a powerful, horizontal fin with a span of up to six meters. When diving, the sperm whale extends its caudal fin above the surface of the water.
They usually dive to depths of 300 to 800 meters, but sometimes it’s from 1 to 2 kilometers or even more. As of 2018, the record holder in diving is the Cuvier’s beaked whale, whose record is 2992 meters in 138 minutes.
Cetaceans dive in search of food. Dives can last up to an hour, usually 35 minutes at a depth of 400 meters. Sperm whales feed on several species, especially giant squid, octopus, and fish, but their diet consists mainly of medium-sized squid.
Surveys conducted in the Galapagos show that they mostly feed on squid of the genus Histioteuthis (62 percent), Ancistrocheirus (16 percent) and Octopoteuthis (7 percent). It is estimated that the total annual food consumption of squid worldwide is about 91 million tons (human seafood consumption is estimated at 115 million tons).
The sounds (clicks) they make are among the most powerful sounds in the animal kingdom. It has even been hypothesized that they can stun their prey with their clicks.
Sound pressure levels exceeding 230 dB (a cannon shot is about 150dB) have been measured, which, according to some theories, can stun or confuse prey.
When diving, they keep their metabolism to a minimum and supply blood only to their most important organs: the heart, brain, and spinal cord. They can store a large amount of oxygen in their blood and muscles.
Sperm whales’ blook has 50 percent higher hemoglobin content than that of humans.
In special situations when they feel threatened, they can accelerate up to 20 kilometers per hour.
It is assumed that healthy adult spermaceti have no natural enemies, except humans, Juveniles (calves), and sick or injured individuals may fall prey to orcas or larger sharks.
Currently, the population of sperm whales is estimated from 1 million individuals to 360.000 thousand.
Females become fertile at about 9 years of age (the oldest recorded pregnant female was 14). Pregnancy lasts 14 to 16 months and one calf is born. Females give birth once every 4 to 20 years. Lactation lasts from 19 to 42 months, but calves can sometimes suckle up to 13 years.
Sperm whale milk has about 36 percent fat (cows’ milk has 4 percent) and has the consistency of cottage cheese, which prevents it from dissolving in water. The energy value of this milk is 3840 kcal/kg. Calves can also suckle from females other than the mother.
In July, they separate the sexes. Males can then be found off the coast of Norway, and females in areas of the Caribbean Sea. They form small flocks, swimming together. Every 45 to 55 minutes, they rise above the surface of the water to take a breath, expelling a stream of heated air about one meter high. After a few dozen breaths, they submerge again.
They are nicknamed “marine ecosystem engineers.” When they surface, they excrete nutrient-rich faces. The iron-rich feces promote the growth of phytoplankton, which benefits the marine food chain and absorbs carbon dioxide. Thanks to whale feces, nutrient cycling takes place, especially the circulation of nitrogen in the ocean.