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The Whale Shark (Rhincodon typus) is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of 18.8 m. The whale shark holds many records for size in the animal kingdom, most notably being by far the most massive living non-cetacean animal. It is the sole member of the genus Rhincodon and the only extant member of the family Rhincodontidae, which belongs to the subclass Elasmobranchii in the class Chondrichthyes.
Before 1984 it was classified as Rhiniodon into Rhinodontidae. Whale sharks inhabit the open waters of all tropical oceans. They are rarely found in water below 21 °C. 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. 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. They feed almost exclusively on plankton and small fishes and pose no threat to humans.
Whale Shark – Squalo Balena – Rhincodon typus – www.intotheblue.it – www.intotheblue.link
Whale sharks possess a broad, flattened head with a large mouth and two small eyes located at the front corners. Unlike many other sharks, whale shark mouths are located at the front of the head rather than on the underside of the head. A 12.1 m. whale shark was reported to have a mouth 1.55 m. across. Whale shark mouths can contain over 300 rows of tiny teeth and 20 filter pads which it uses to filter feed. The species are located just behind the eyes. Whale sharks have five large pairs of gills.
Their skin is dark grey with a white belly marked with an arrangement of pale grey or white spots and stripes that is unique to each individual. The skin can be up to 15 cm. thick and is very hard and rough to the touch. The whale shark has three prominent ridges along its sides, which start above and behind the head and end at the caudal peduncle. The shark has two dorsal fins set relatively far back on the body, a pair of pectotal fins, a pair of pelvic fins and a single medial anal fin. The caudal fin has a larger upper lobe than the lower lobe.
Whale Shark – Squalo Balena – Rhincodon typus – www.intotheblue.it – www.intotheblue.link
The whale shark inhabits all tropical and warm-temperate seas. The fish is primarily pelagic, and can be found in both coastal and oceanic habitats. Tracking devices have shown that the whale shark displays dynamic patterns of habitat utilization, likely in response to availability of prey. Whale sharks are known to prey on a range of planktonic and small nektonic organisms that are spatiotemporally patchy.
These include krill, crab larvae, jellyfish, sardines, anchovies, mackerels, small tunas, and squid. In ram filter feeding, the fish swims forward at constant speed with its mouth fully open, straining prey particles from the water by forward propulsion. This is also called ‘passive feeding’, which usually occurs when prey is present at low density.
Whale Shark – Squalo Balena – Rhincodon typus – www.intotheblue.it – www.intotheblue.link
This video was made in Oslob, Philippines, where the whale sharks are fed shrimp by the locals. The sharks have become accustomed to showing up every morning and tourist operators have made a business out of it by bringing visitors, divers and scholars to admire and photograph these splendid fish. This daily opportunity lasts a very short time because the sharks resume their pelagic life after the “snack” offered.
(extract from Wikipedia)
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