Common Name and Meaning: Common names include Swordfish and Broad bill. They are named this because of their bill resembling a sword. When was it Discovered: Fossils date back 15 million years ago Related Animals: They are related to other bill fish, such as the Marlin. Evolutionary History: Fossils are hard to come by, the oldest dating back to 15 million years ago. The swordfish has barely changed since they first evolved.
Description
Size and Weight: They commonly reach 3 m (9.8 ft) in length, and the maximum reported is 4.55 m (14.9 ft) in length and 650 kg (1,430 lb) in weight. Symmetry: If you look straight on the swordfish has bilateral symmetry, but if you look at it from the side it is not symmetrical. Color: While all Swordfish are dark above and whitish with silvery sheen below, the upper surface varies from a purplish to a laden blue or even black. Body Covering: Swordfish have skin. They have gills at a young age, but once mature they don't have gills anymore. Eyes/visual: Swordfish have organs near their eyes and brain that heat up their eyes, this allows them to see better at deeper and colder depths of the water. Their eyes grow to be the size of tennis balls. Nostril: The nostril is located near their eyes, where the sword starts. They are no bigger than a dime on a mature fish. Ear: Swordfish hear, but their "ears" are on the inside. Swordfish detect vibration through their "ear stones" called otoliths.