Adult male killer whales are larger overall than their female counterpart including features such as pectoral flippers, dorsal fins, tail flukes, and girth. The largest recorded male killer whale was 9.8 m (32 ft.) in length and weighed 10,000 kg (22,000 lbs.) The largest recorded female was 8.5 m (28 ft.) and weighed 7,500 kg (16,500 lbs.). Data from Icelandic killer whales (North Atlantic type 1) indicate that an average-size male is about 5.8 to 6.7 m (19 to 22 ft.) long, while females averaged 4.9 to 5.8 m (16 to 19 ft.) long. Killer whale sizes vary significantly between different ecotypes.
Male Antarctic type A killer whales can reach lengths of 9.2 m (30 ft.) making them the largest known killer whales. The smallest killer whale ecotype is the Antarctic type C killer whales in which adult females average 5.2 m (17 ft.) and adult males average 5.6 m (18 ft.) in length and can reach a maximum of 6.1 m (20 ft.). At SeaWorld, average size for adult males is 6.6 m (21.7 ft.) Two of the largest adult male killer whales at SeaWorld weigh 4,340 kg (9,570 lbs.) and 5,380 kg (11,860 lbs.).
At SeaWorld, average size for females is 5.5 m (18 ft.) and 2,442 kg. (5,384 lbs.) SeaWorld's adult female whales range in weight from 2,313 kg (5,100 lbs.) to 3,719 kg (8,200 lbs.). The general body shape of a killer whale is roughly cylindrical but tapering at both ends. This characteristic fusiform shape is quite energy efficient for swimming. Â Killer whales are black and white, with a gray patch called a "saddle" or a "cape" on the back, just behind the dorsal fin. 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. 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. Like the flukes, the dorsal fin is made of dense, fibrous connective tissue, without bones or cartilage. A killer whale has an indistinct rostrum (snout-like projection).
A single blowhole on top of the head is covered by a muscular flap. A killer whale breathes through its blowhole. The blowhole is relaxed in a closed position, and the flap provides a water-tight seal. To open its blowhole, a killer whale contracts the muscular flap.
A killer whale's eyes are on each side of its head, just behind and above the corner of its mouth, and in front of its white eyespot.
A killer whale's large teeth are conical and interlocking. Toothed whales have only one set of teeth; they are not replaced once lost. The number of teeth varies among individuals. There are usually 10 to 14 teeth on each side of each jaw (40 to 56 teeth total). A killer whale's blubber layer lies beneath the dermis and measures from 7.6 to 10 cm (3 to 4 in.) thick. Blubber is a layer of fat reinforced by collagen and elastic fibers. In general, blubber has a number of important functions: A killer whale's dermis (skin) is smooth. The outer layer continually and rapidly renews itself, and the old skin sloughs off. The increased skin cell turnover increases swimming efficiency by creating a smooth body surface which reduces drag.
Facts:
1) The name killer whale derives from their original name ‘whale killers’ given to them by sailors who saw them hunting whales. Over time, the name eventually switched around.  The name ‘orca‘ comes from their Latin species name Orcinus orca, where orcinus translates to mean ‘Kingdom of the dead’.
2.  Despite their name, killer whales are actually a dolphin – the largest species of oceanic dolphin!
3.Whilst they can and do eat prey such as finfish and marine mammals, New Zealand orca have become specialised at hunting sharks and rays. They can often be seen up around rocky reefs and in the shallows of beaches while they are hunting.
4.The average life span of an orca is not too dissimilar to a human, at 50-80 years for females and slightly less for males at 29-60 years.
5.Orca can be seen in every ocean on the earth. They are one of the most successful marine mammals in terms of range.
