About Killer Whale Size
Adult male killer whales are larger than their female counterpart, including features such as pectoral flippers, dorsal fins, caudal paws and girth. Male killer whales reach a length of 10 m and have a mass of up to 8 tons, females – up to 8.7 m long.
The sizes of killer whales vary significantly between different ecotypes.
Male killer whales of Antarctic type A can reach a length of 9.2 m (30 feet), which makes them the largest known killer whales.
The smallest ecotype of killer whales is Antarctic type C, in which adult females average 5.2 m (17 feet) and adult males average 5.6 m (18 feet) in length and can reach a maximum of 6.1 m (20 feet).
The dorsal fin in males is high (up to 1.5 m) and almost straight, and in females it is about half as low and bent.
The head is short, flattened from above, without a beak; teeth are massive, up to 13 cm long, adapted to tear large prey.
Body Shape of Orca
The shape of the killer whale body is streamlined and tapering at both ends. This form is energy efficient for swimming. It creates less water resistance when swimming compared to other animals.
Color of Killer Whales
The color of killer whales is their species-specific feature. The back and sides of the animal are black, the lower jaw, throat and belly are white. In the back of the body, a white color with two fangs rises to the caudal stem on the sides up, sometimes reaching the back. Two white spots are located in front of and above the eyes. On the vertical of the dorsal fin, two white spots can be located on the sides, merging behind the dorsal fin into one saddle-shaped spot, which serves researchers to recognize individual animals “in the face.” In the waters of the Arctic of the Antarctic, light areas of the skin of killer whales may have a yellowish-greenish or brown tint due to the diatom algae film covering them.
Killer whales have 10-14 teeth in each half of the upper jaw, and 8-14 in the lower. With a closed mouth, the teeth of the upper jaw enter the gaps between the teeth of the lower, which helps when setting prey or biting off part of it.
Distribution and migration of killer whales
Killer whales are found in almost all areas of the World Ocean, both near the coast and in open waters. Killer whales live everywhere in the Atlantic Ocean: from the shores of Greenland and Svalbard to the Antarctic region. They are ordinary guests in the Mediterranean Sea. The Indian Ocean is inhabited up to Australia, and in summer they are found circumpolar in the waters of the Antarctic, reaching the ice border.
In Arctic waters, they are distributed intermittently: killer whales were not found in the East Siberian Sea and the Laptev Sea, although they are known in the Barents Sea, the western and northwestern parts of the Kara Sea, off the coast of Murman and in the White Sea. In the Far East of Russia, killer whales are often found in the Sea of Japan and Okhotsk, off the coast of Kamchatka, the Kuril and Commander Islands, as well as in the Bering Sea. A.G. Tomilin, back in 1951, noted that in the Kamchatka coastal waters, killer whales were most often observed at Cape Shipunsky, where the Sivucha lodge is located, in the Olyutorsky and Avachinsky bays.
Reproduction and development
Mating killer whales in nature is quite difficult to register, since sexual behavior in dolphins is often observed in the context of social and game activity, including between same-sex individuals. However, studies of dried animals suggest that conception occurs in the summer months and early autumn. The duration of pregnancy is not precisely established, although it is believed that the carrying of the cub lasts 16-17 months. In Canada, baby killer whales are born mainly from October to March. It is possible that the reproductive cycle of killer whales varies in various areas of the World Ocean, since, according to Russian researchers E.I.
Ivanova and V.A. Zemsky, the birth of cubs is timed to summer months, and according to the results of Norwegian scientists – to early autumn. As part of our research, the birth of a cub in early August was once reliably recorded.
The body length of the newborn is 250-270 cm, and by the year it reaches 350 cm. Females grow to about 10 years old, and the first viable offspring are born between the 12th and 18th years of life. Males reach the size of an adult female by the eighth year of life and continue to increase in size up to 15 years. The physical maturity of males occurs at 18-20 years old. Determination of the age of growing males is possible by the HWR coefficient (ratio of height to width of the dorsal fin), each value of which corresponds to a certain age of the male killer whale.
The life expectancy of killer whales has not been precisely established, but in 1987 Olesiuk and his colleagues observed two females whose age was determined to be 77 years old. Calculations of the age of some females, based on the number and age of their descendants, showed that the oldest of them may have reached their 90th birthday. The maximum life expectancy of males cannot be determined, since from the moment of puberty and physical maturity, external changes do not occur to them. But, based on the quantitative sex ratio of animals that have reached thirty-five years, it is assumed that the life expectancy of males is much shorter than the life expectancy of females and does not exceed 50-60 years.
A killer whale’s forelimbs are adapted for swimming. A killer whales uses its rounded, paddlelike pectoral flippers to steer and, with the help of the flukes, to stop. Pectoral flippers have the major skeletal elements of the forelimbs of land mammals, but they are shortened and modified. The skeletal elements are rigidly supported by connective tissue. Blood circulation in the pectoral flippers adjusts to help maintain body temperature.
The pectoral flippers of male killer whales are proportionately larger than those of females. A large male killer whale may have pectoral flippers as large as 2 m (6.5 ft.) long and 1.2 m (4 ft.) wide. A female’s pectoral flippers are significantly smaller.
A killer whale’s pectoral flipper contains 5 digits much like the fingers on a human hand.
Each lobe of the two-lobed tail is called a fluke. Flukes are flat pads of tough, dense, fibrous connective tissue, completely without bone or cartilage.Although killer whales have 50 to 54 vertebrae, no bones extend into the flukes. Without bones or even cartilage in the flukes, it is not unusual to see them curved, especially in larger males. A large male killer whale may have tail flukes measuring 2.75 m (9 ft.) from tip to tip. Longitudinal muscles in the back one-third of the body (both above and below the spine) move the flukes up and down. Like the arteries of the flippers, the arteries of the flukes are surrounded by veins to help maintain body temperature.
Dorsal fin is made of dense fibrous connective tissue, without bones or cartilage. The size and shape of the dorsal fin differs from species to species. The dorsal fin of the male killer whale is proportionally larger than that of the female.
In adult males, the dorsal fin is high and triangular. Reaching a height of up to six feet, in a large adult male, it is the highest dorsal fin of all cetaceans.
In most females, the dorsal fin is slightly posterior and smaller – from about 3 to 4 feet tall.
Like paws and flippers, the arteries in the dorsal fin are surrounded by veins that help maintain body temperature.
The dorsal fin can help stabilize the killer whale when it swims at high speeds, but the fin is not essential to the whale’s balance.
The single opening at top of the head is blocked by a muscular rag. The killer whale breathes through the hole. The blowing-off well is weakened in a closed position, and the shutter provides waterproof consolidation. To open the hole, the killer whale squeezes a muscular rag.
Eyes of killer whales from each side of the head, directly for and over a mouth corner, and before a white eye spot. Eyes of killer whales approximately same size, as eye of a cow. Glands in internal corners of eye-sockets excrete slime, oily, similar to jelly, which greases eyes, washes away fragments and probably helps to order eyes as the killer whale floats.
Ears represent small imperceptible dimples behind each eye, without external rags or a pin at once. These small external ear openings lead to reduction of ear canals which aren’t connected to middle ears.
Physical Differences in Ecotypes
The five forms of Antarctic killer whales look different and are easier to distinguish from each other.
- Type A killer whales have a medium size, a horizontal eye patch and a very weak dorsal saddle. These are the largest ecotypes of killer whales.
- Large killer whales of type B have a very large, horizontal eye patch. The small killer whale of type B has a slightly narrower and inclined eye patch. Both types have a dorsal saddle, a dorsal nappy (dark gray coating on the back), and may have a yellowish cast due to the diatoms layer on their skin.
- Type C killer whales have a small, forward-inclined eye patch and dorsal saddle and often have a yellowish cast due to diatom coating. This is the smallest species of killer whales.
- Type D killer whales have an extremely tiny eye patch, onion melon (forehead) and a very weak saddle.
- Experts note subtle differences between the inhabitants, transitional and marine killer whales of the eastern part of the North Pacific Ocean.
In general, resident killer whales are larger and have a rounded tip on the dorsal fin, which is a falcate (curved backward) in adult females and tall and triangular in males. The dorsal saddle may contain some black areas.
Transient killer whales are usually smaller and have a more pointed dorsal fin. The dorsal saddle does not contain any black areas. Marine killer whales are more similar in appearance to the resident ecotype, although they are smaller than either inhabitants or transitional and have a weak saddle.
Ecotypes of killer whales of the North Atlantic.
Type 1 killer whales are significantly smaller than type 2. They have very distinct white eye spots and a noticeable saddle.
Type 2 killer whales are one of the largest ecotypes, with males reaching 8.5 m (29 feet) of length. They have very distinct white spots, an inclined eye patch and a weak saddle.