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Rhincodontidae is a shark family which includes the whale shark, the sole extant member and the largest living fish. A single extinct genus, Palaeorhincodon , is known from the Paleocene as well. [ 1 ]
Unlike traditional scales, sharks have placid scales, known as denticles. Denticles are V-shaped and are made of layers of dentine and a surface of enamel. [24] Riblets are sockets in the shark's skin which hold the denticles. [22] These denticles on the skin allow for the shark to move quietly, swiftly, and almost effortlessly.
A spiracle is a small hole found behind each eye. These can be tiny and circular, such as found on the nurse shark (Ginglymostoma cirratum), to extended and slit-like, such as found on the wobbegongs (Orectolobidae). Many larger, pelagic species, such as the mackerel sharks (Lamnidae) and the thresher sharks (Alopiidae), no longer possess them.
Sharks range in size from the small dwarf lanternshark (Etmopterus perryi), a deep sea species that is only 17 centimetres (6.7 in) in length, to the whale shark (Rhincodon typus), the largest fish in the world, which reaches approximately 12 metres (40 ft) in length. They are found in all seas and are common to depths up to 2,000 metres (6,600 ...
Whale sharks' lifespans are estimated to be between 80 and 130 years, based on studies of their vertebral growth bands and the growth rates of free-swimming sharks. [ 9 ] [ 10 ] [ 11 ] Whale sharks have very large mouths and are filter feeders, which is a feeding mode that occurs in only two other sharks, the megamouth shark and the basking shark .
English: The size and growth of the whale shark (Rhincodon typus), represented by various individuals reported in the literature.A small 55 centimetres (22 in) pup, a 5.62 metres (18.4 ft) juvenile, a generic 9 metres (30 ft) young adult, a large 12.1 metres (40 ft) adult, and an exceptionally large adult with a precaudal length of 15 metres (49 ft).
Due to their primitive anatomy, hexanchiforms were previously considered the most basal group of sharks. However, more recent phylogenetic studies indicate that while primitive, they in fact belong to the superorder Squalomorphii, which also contains dogfishes, angelsharks, and sawsharks, although they are thought to be the most basal member of the group.
Sharkbook is a global database for identifying and tracking sharks, particularly whale sharks, using uploaded photos and videos.In addition to identifying and tracking sharks, the site allows people to "adopt a shark" and get updates on specific animals.