A 2020 study looked at the growth of whale shark individuals over a 10-year period.
Evidence suggests that whale sharks exhibit sexual dimorphism with regards to size, with females growing larger than males. The whale shark is the largest non- cetacean animal in the world. The mutations thus allow the shark to see well at both ends of its great vertical range. The rhodopsin is stable, however, in the colder environment at 2000 meters below the surface where the shark dives and only blue light reaches.
#Wuala speices full
These mutations make the whale shark's rhodopsin unstable in shallow water where the temperature is higher and the full spectrum of light is present as otherwise the pigment would hinder full color vision. Whale sharks have mutations at sites that in humans cause congenital stationary night blindness. The complete and annotated genome of the whale shark was published in 2017. Their spot markings have also been shown to reform over a previously wounded area. Įvidence suggests that whale sharks can recover from major injuries and may be able to regenerate small sections of their fins. These denticles serve to protect the eye from damage, along with the whale shark's ability to retract its eye deep into its socket. Whale sharks have been found to possess dermal denticles on the surface of their eyeballs that are structured differently from their body denticles. The caudal fin has a larger upper lobe than the lower lobe ( heterocercal). The shark has two dorsal fins set relatively far back on the body, a pair of pectoral fins, a pair of pelvic fins and a single medial anal fin. The whale shark has three prominent ridges along its sides, which start above and behind the head and end at the caudal peduncle.
#Wuala speices skin
The skin can be up to 15 cm (5.9 in) thick and is very hard and rough to the touch. 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. Whale sharks have five large pairs of gills. The spiracles are located just behind the eyes. Whale shark mouths can contain over 300 rows of tiny teeth and 20 filter pads which it uses to filter feed. A 12.1 m (39.7 ft) whale shark was reported to have a mouth 1.55 m (5.1 ft) across. Unlike many other sharks, whale shark mouths are located at the front of the head rather than on the underside of the head. Whale sharks possess a broad, flattened head with a large mouth and two small eyes located at the front corners. In addition, its filter feeding habits are not unlike those of baleen whales. The name "whale shark" refers to the fish's size: it is as large as some species of whale. Andrew Smith, a military doctor associated with British troops stationed in Cape Town, described it the following year. The species was distinguished in April 1828 after the harpooning of a 4.6 m (15 ft) specimen in Table Bay, South Africa. They feed almost exclusively on plankton and small fishes, and pose no threat to humans. 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. Studies looking at vertebral growth bands and the growth rates of free-swimming sharks have estimated whale shark lifespans at 80–130 years. The whale shark is found in open waters of the tropical oceans and is rarely found in water below 21 ☌ (70 ☏). Before 1984 it was classified as Rhiniodon into Rhinodontidae. 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. The whale shark holds many records for size in the animal kingdom, most notably being by far the largest living nonmammalian vertebrate. The largest confirmed individual had a length of 18.8 m (61.7 ft). The whale shark ( Rhincodon typus) is a slow-moving, filter-feeding carpet shark and the largest known extant fish species.
0 kommentar(er)
