Top 13 Fascinating Facts About Abyssal Fish - Mytour.vn

Burial house fish is the largest toothed whale in the world, with males reaching lengths of 13-16m and weighing between 35-50 tons. In comparison, the second-largest toothed whale, Baird's beaked whale, only reaches 12.8 meters (42 ft) in length and weighs 15 tons. The Nantucket Whale Museum still holds a jawbone from a burial house fish measuring 5.5 meters (18 ft). According to the museum, this jawbone belongs to an 80-foot (24 m) burial house fish, while the one that sank the whaling ship Essex (inspiration for the novel Moby-Dick) is believed to be 85 feet (26 m) long. However, there are conflicting opinions about the size of fully grown male burial house fish exceeding 80 feet (24 m).

The large-scale whaling, especially after World War II, likely contributed to the decrease in the average size of burial house fish, as large males were often targeted by hunters. Currently, male burial house fish typically do not exceed 18.3 meters (60 ft) in length and 51,000 kilograms (50 tons UK; 56 tons US) in weight. Some argue that overfishing has had little impact on the size of male burial house fish and, in fact, their size should increase as individual density decreases, resulting in an increase in food per fish head.

Burial house fish is the whale species with the most pronounced sexual dimorphism[3]. While males and females are similar in size at birth, mature males are 30% to 50% longer and three times heavier than females.

The English name for cá nhà táng (sperm whale) is a shortened form of spermaceti whale (whale with sperm oil, here spermaceti oil was once mistakenly thought to be the sperm of the whale). Spermaceti oil is a semi-fluid, waxy substance found in the oil sac located in front of the whale's skull, as well as in the spermaceti organ, a tissue located above the skull and below the oil sac. The outer layer consists of a white, saturated wax substance mixed with spermaceti oil. The spermaceti organ encases cavities containing wax similar to that in whale oil and intermediate tissues.

Previously, the cá nhà táng was also called the 'toothed whale' (cachalot). The term 'cachalot' comes from a French word meaning 'tooth' or 'large tooth' (this term is still preserved in the Gascon language in a variant form as the word cachau). The etymological dictionary of Corominas states that the origin of this word is unclear, but it may come from a common Latin word cappula, the plural of cappulum, meaning sword hilt.

According to the Encarta dictionary, the term cachalot came into English through the Spanish or Portuguese word cachalote and may come from the Portuguese word cachola, meaning 'large head.' This term is also used in Russian (кашалот - kashalot) as well as many other languages.

The sperm whale, along with the bottle-nose dolphin and the beaked whale, holds the record as one of the deepest-diving mammals in the world. The sperm whale is believed to dive up to 3 kilometers (1.9 mi) and can hold its breath underwater for as long as 90 minutes. However, typically, the creature only dives to about 400 meters (1,300 ft) and holds its breath for around 35 minutes. Occasionally, during deep dives, sperm whales get entangled in undersea cables and tragically drown until advancements in cable installation and maintenance are implemented.

The unique lifestyle requires sperm whales to adapt to significant and abrupt changes in water pressure when diving into the ocean depths. The animal's flexible chest allows the lungs to contract, reducing nitrogen absorption; the metabolic process is also minimized to conserve oxygen. The myoglobin content, the oxygen-carrying substance primarily found in muscles, of sperm whales is much higher than in land-dwelling animals. The blood of the creature also has a high concentration of red blood cells—hemoglobin-carrying cells—allowing it to store a considerable amount of oxygen. Oxygen-enriched blood is transported directly to the brain and vital organs when oxygen levels drop low. Additionally, the spermaceti organ at the sperm whale's head contributes to adjusting the creature's buoyancy.

Despite adapting well to deep diving, repeated deep dives take a toll on sperm whales. The skeletons of surviving adult sperm whales exhibit small holes, indicative of decompression sickness or commonly known as the bends. Older whales have more holes compared to younger ones. From this, it can be inferred that decompression sickness is a significant issue for sperm whales, and sudden surfacing can have detrimental consequences for the creature.

Between deep dives, sperm whales need to surface for approximately 8 minutes to breathe, preparing for the next dive. Sperm whales, like other toothed whales, breathe through an S-shaped blowhole on the top of their heads. During such brief breathing intervals, the animal breathes about 3-5 times per minute, but immediately after surfacing, this rate increases to around 6-7 times per minute. Each breath expelled by the sperm whale can create a water spout reaching up to 2 meters (6.6 ft) or more, forming a 45-degree angle along with a loud, distinctive noise. On average, female and juvenile sperm whales take a breath every 12.5 seconds before diving, while mature males take 17.5 seconds.

The sperm whale possesses a distinctive and easily distinguishable body shape. Specifically, their heads are exceptionally large and block-shaped, constituting roughly 1/4 to 1/3 of the body length. The S-shaped blowhole is situated near the front of the head and slightly tilts to the left of the body. This structure gives the sperm whale a very robust appearance, especially towards the front.

The tail of the sperm whale is triangular and very robust. When preparing for a deep dive to search for food, they raise their tails high above the water's surface. Sperm whales lack a dorsal fin; instead, a series of small ridges called 'knuckles' grow along their back, with the largest ridge known to whalers as the 'hump' and often mistaken for the dorsal fin of a smaller fish or whale. Sperm whales don't have smooth skin like most larger whale species; instead, their dorsal skin is wrinkled, rough, and often reminiscent of a dried apricot. Typically, the skin of sperm whales appears dark gray, though under sunlight, they may seem brownish. Albino sperm whales have also been documented.

The lower jaw of the sperm whale is very narrow and is supported from above. The creature has between 18 to 26 teeth on each side of the lower jaw, which interlock with holes in the upper jaw that naturally lacks teeth. The teeth of the sperm whale are cone-shaped and can weigh up to 1 kilogram (2.2 lbs) each. These teeth serve certain functions in the life of a sperm whale, although they seem not strictly necessary for hunting and consuming prey such as squid; individuals with a full diet but lacking teeth have been found. One hypothesis suggests that the teeth of the sperm whale are used in competitions between males. Mature males exhibit scars on their bodies, likely resulting from bites. Signs of tooth resorption also appear in the upper jaw, but they rarely emerge within the mouth.

The spermaceti organ also plays a role in regulating the buoyancy of the sperm whale. One hypothesis suggests that, before the animal dives, cold water enters the spermaceti organ, causing the blood vessels to contract, reducing blood flow, and lowering the temperature of this area. The whale's head oil and wax consequently solidify, decreasing volume, increasing relative weight, and generating a downward force of approximately 392 newtons ([conversion: inappropriate units]), aiding the sperm whale in diving with less effort. During prey hunting, oxygen consumption, along with the expansion of blood vessels generating heat and melting the spermaceti, contributes to buoyancy, making it easier for the whale to surface. However, recent studies have shown flaws in this theory, such as not accounting for the body structure used for actual heat exchange.

In Herman Melville's Moby Dick, the spermaceti organ cavity evolved so that males could ram their heads together in battles between male sperm whales. However, there is almost no recorded evidence of such battles. Except for a few well-known cases like the whaling ships Essex and Ann Alexander being sunk by sperm whales weighing only 1/5 of the ships, the 'ramming' hypothesis is not strongly supported in current scientific literature.

Additionally, the sperm whale's brain is the largest among all known or extinct animals, weighing up to 8 kilograms (18 lbs). However, the brain-to-body mass ratio of the creature is not highly ranked, generally lower than dolphins, many other whale species, lower than human primates, and significantly lower than humans.

Previously, the nose complex of the sperm whale (including the spermaceti organ, sperm whale oil-producing organ, and associated internal organs) was used for head-butting enemies or adjusting its buoyancy. However, recent studies reveal that this complex is one of the most powerful echolocation systems in nature.

As light gradually absorbs in the underwater environment, almost becoming pitch-dark beyond a few hundred meters deep, the ocean interior becomes obscure, limiting visibility. Therefore, sperm whales and other toothed whale species have developed an echolocation system to find food and navigate obstacles in the dark sea. A similar method is also employed by species in the suborder Microchiroptera when hunting at night. Specifically, while diving, sperm whales continuously emit spaced sounds with a wide frequency range, and these sounds propagate in a specific direction. These sounds are emitted at two sound-emitting structures (also known as 'monkey lips' or 'singing lips') at the front of the nose, just ahead of the blowhole. These sound waves will rebound towards the nose, passing through the sperm whale's oil-containing organ. Most of the sound energy from here rebounds to an air sac resting against the skull and then moves down the wax organ, where sound is focused on a lens-shaped structure of tissue. Some sound will rebound to the sperm whale's oil organ and run forward to the nose again. The sound keeps bouncing back and forth like this many times in just a fraction of a second, creating a complex pattern of clicks.

This structure enables researchers to measure the sperm whale's oil organ solely based on the sounds it emits, and the size of this organ correlates with the size of the whole animal. Biologists can gauge the size of sperm whales by observing the sounds they produce. The lower jaw of the whale is the primary receiver of echoed sounds, and a continuous tube filled with fat plays a role in transferring received sounds into the inner ear.

The sound source passes through the sound-emitting structure via the right nostril tube. While the left tube plays a role in opening and closing the air outlet, the right tube has evolved to supply air to the sound-emitting structure. It is believed that these two air tubes originated from the two nostrils of the sperm whale's ancestors when they still lived on land. When evolving to adapt to underwater life, the left nostril must have become the sound-emitting structure, while the right nostril became the air outlet for breathing.

Female sperm whales typically travel in pods of about 12 individuals, including their offspring. Mature males leave the pod when they are between 4 to 21 years old. Adult males sometimes form loosely associated groups with individuals of similar age and size. Older males tend to live solitary lives. Male whales have been observed gathering near the coast together, indicating some level of cooperative relationships, although the nature of this collaboration is not fully understood.

The most common natural predator of sperm whales (excluding humans) is the killer whale, but false killer whales and pilot whales can also harass them. Killer whales often target pods of female sperm whales, usually aiming to hunt the young ones in the group. If the killer whale pod is too large, they may even kill an adult female sperm whale. Adult male sperm whales are considered too large and robust to be threatened by killer whales, and they have no natural predators other than humans.

When under attack, a pod of female sperm whales immediately forms a protective circle around the calves, heads facing inward, and tails outward to strike the attacking foe. Sometimes, female whales turn outward and combat the enemy with their sharp-toothed jaws. This formation is known as the 'western daisy' and is also employed to shield an injured member within the pod. This behavior is exploited by whalers: intentionally injuring a member of the sperm whale pod causes the entire pod to circle in one place, making it easier to capture all of them.

Sperm whales are among the most globally distributed species. They prefer non-ice-covered waters deeper than 1,000 meters (3,300 ft). Both males and females inhabit tropical and temperate seas, with only males present at higher latitudes.

Sperm whales have a high presence from polar regions to the equator, in all oceans, including enclosed seas like the Mediterranean. However, they do not appear in the Black Sea, and their presence in the Red Sea is not conclusively confirmed. These seas have narrow entrances with shallow depths, believed to be the reason for the absence of sperm whales in these areas. Additionally, the lower layers of the Black Sea have extremely low oxygen levels and high concentrations of sulfur compounds.

The density of sperm whales is higher in continental slope and submarine canyon regions formed by the erosion of currents. They are also found in deep-sea regions offshore, but in areas with narrow continental shelves, they tend to stay closer to the shore, and the density of the animals rapidly decreases in waters with depths of 310–920 meters (1,020–3,020 ft). Coastal areas with large populations of sperm whales include the Azores archipelago and Dominica island.

The lifespan of sperm whales can reach 70 or more years. They represent a K-selected species with a reproductive strategy suitable for a stable environment, characterized by low birth rates, meticulous parental care, late maturity, and high longevity. The mating behavior of sperm whales is not fully understood. There is evidence suggesting that male whales have a socially dominant role, but female whale choice also has significant influences. The gestation period lasts from 14 to 16 months, with each female giving birth to one calf. The lactation period varies from 19 to 42 months, although some rare sperm whale calves may nurse until they are 13 years old. Calves can also suckle from females other than their mothers. Typically, sperm whales give birth once every 3 to 6 years.

Female sperm whales reach sexual maturity around 7 to 13 years, while males mature around 18 years. Upon maturity, males move to higher latitudes where the water is colder and the food supply is richer, whereas females continue to live in low-latitude areas. Males reach their maximum body size at around 50 years old.

Ambergris is a gray waxy substance formed in the digestive system of sperm whales. Formerly used in the perfume industry, ambergris is now mostly replaced by synthetic materials and is only found in some expensive perfumes.

Ambergris is produced in the digestive system of sperm whales, but the exact process of its formation is yet to be discovered. Contrary to popular belief, ambergris is not vomited by sperm whales but is excreted along with feces, having a similar scent when freshly expelled.

Professor Jean Maurice from the Department of Chemistry, University of Paris-Sud 11, states: “The characteristic of ambergris is that it retains its fragrance for a very long time. An experiment showed that when a cotton swab dipped in liquid ambergris was placed in an open 750ml bottle of alcohol, after 3 months, the alcohol smell evaporated, but the ambergris fragrance remained intact. This is why the perfume industry relies on it.”

Not only rare and expensive, but ambergris is also one of the most challenging commodities to acquire globally because it entirely depends on sperm whales. According to marine biology experts, on average, only 1 in 100 sperm whales produces ambergris. Professor Maurice continues: “The mechanism of ambergris expulsion in sperm whales is still unclear because giant squid is its preferred food, but not every sperm whale, after consuming it, excretes ambergris.”

As the oxidation process releases water and air from the waste mass, ambergris emits a scent similar to tobacco or the outer layer of a tree. The duration of the oxidation process determines the quality and value of ambergris. Renowned French ambergris buyer Bernard Perrin compares it to fine wine, becoming more exquisite with age.

According to historical records, people in the Middle East ground ambergris into powder and consumed it to enhance virility, boost energy, treat neurological and cardiac conditions, as well as add flavor to food and drinks.

The brain of a sperm whale weighs up to 8kg. Male sperm whales can reach lengths of up to 19m, five times the length of a large elephant. The heart of a sperm whale can weigh up to 125kg. Sperm whales have the largest heads in the world, constituting 25-35% of their total body length. They can dive deeper than 1000m and hold their breath for up to 2 hours.

Sperm whales produce sounds loud enough to rupture your eardrums. There is a theory that suggests they may incapacitate or kill prey using sound. The loudest sound produced by a sperm whale is a series of clicks with a magnitude of 235 decibels when measured at the water's surface. This noise level is equivalent to the sound pressure that the Saturn V rocket generates at a distance of 1m.

Beached sperm whale carcasses can explode. Gas accumulates inside the whale's body as the food it ingested in its stomach decomposes. Due to their tough skin and thick blubber layer, the gas cannot escape, eventually causing the carcass to burst in a powerful explosion.

Every living sperm whale today is a descendant of a female sperm whale. In a study of 1600 sperm whales worldwide, all shared a similar DNA profile, tracing back to a common ancestor, a female sperm whale that lived approximately 80,000 years ago.

Sperm whales often dive from 300 to 800 meters (980 to 2,620 ft) and sometimes up to 1–2 kilometers (3,300–6,600 ft) in search of prey. Each dive can last over an hour. Their diet includes various animals, notably giant squids, Antarctic colossal squids, octopuses, and various fish species that live at the ocean floor. However, the main part of a sperm whale's menu consists of medium-sized squid species. Occasionally, some unfortunate creatures unintentionally become a part of the meal. Most information about deep-sea squids is obtained from studying remnants found in the stomachs of sperm whales, although recent research has focused on the creature's feces. A study in the Galápagos Islands indicated that squid genera Histioteuthis (62%), Ancistrocheirus (16%), and Octopoteuthis (7%) weighing around 12 to 650 grams (0.026 to 1.433 lbs) are the primary prey of sperm whales.

Sperm whales hunting Antarctic colossal squids (a species that can weigh nearly 500 kilograms or 1,100 lbs) has not been observed, but scars on sperm whale skin, as shown in the image, could be attributed to this species resisting the whale's attempts at capture. A study published in 2010 suggested evidence indicating that female sperm whales may cooperate when hunting Humboldt squids.

In a previous survey of sperm whales caught in the Cook Strait by New Zealand whaling vessels, the mass ratio of squid to fish in their diet was 1.69:1. Sperm whales sometimes opportunistically 'snatch' fish from the areas where longline fishing vessels operate, such as Chilean hake and Patagonian toothfish. Alaskan longline fishermen complain that sperm whales often encroach on their fishing areas to 'steal' catches because of the high concentration of fish in these spots, saving the whales from the effort of hunting for prey.

However, the stolen catch is negligible compared to the whale's needs. In one instance, a male sperm whale was observed 'hovering' for an extended period to catch fish. The megamouth shark, a large and rare deep-sea shark, is also believed to be part of the sperm whale's diet. The megamouth shark has been observed being surrounded or attacked by three sperm whales. Nevertheless, sperm whales have a formidable adversary in the ocean—the killer whale. According to estimates, killer whale pods have conducted attacks on sperm whale groups, especially resulting in numerous deaths among the young ones. Therefore, sperm whales avoid confrontations with killer whales. In fact, sperm whales rarely interact with killer whales as they dive deep into the ocean.

As the largest carnivore in the ocean, the sperm whale has an extraordinary source of food. Its diet is acquired after hours-long dives to the ocean floor where the most abundant food sources are found. Sperm whales consume squid, octopus, rays, and various fish, but predominantly medium-sized squid. The amount of food they can intake is truly record-breaking; in a year, their food consumption surpasses that of humans by a significant margin.

The sperm whale's food consumption is exceptional, with them consuming an amount equivalent to 3% of their body weight daily. The annual food mass the sperm whale ingests reaches up to 100,000,000 US tons (91,000,000 t) — surpassing the amount of seafood consumed by humans in the same timeframe.

Until now, researchers are unsure why the sperm whale's head is disproportionately large compared to its lower jaw. One hypothesis suggests that the echolocation ability used in hunting is the reason for the enlarged head. However, the primary prey of sperm whales, squid, has acoustical properties too similar to water, making echolocation less effective. The sound-producing structures on the sperm whale's head can create a source level of over 230 decibels re 1 micropascal at a distance of 1 meter (3.3 ft) — the largest sound produced by any animal, exceeding the sound of a powerful gunshot heard from approximately 1 meter (3.3 ft) away by 10–14 dB. Another hypothesis is that the loud noise is generated to stun the prey, though experiments producing similar sounds did not inflict desired injuries on targets.

The spermaceti of the sperm whale is believed to be formed by masses of squid beaks trapped in the creature's stomach, akin to the formation of pearls. Specifically, these squid beak masses stimulate the sperm whale's duodenal tissue, triggering the secretion of a lubricating substance in the creature's gut.