Angel shark

The angelsharks are a group of sharks in the genus Squatina in the family Squatinidae, which are unusual in having flattened bodies and broad pectoral fins that give them a strong resemblance to rays. This genus is the only one in its family and order Squatiniformes. They occur worldwide in temperate and tropical seas. Most species inhabit shallow temperate or tropical seas, but a few species inhabits deeper water, down to 1,300 m (4,300 ft). Angel sharks are sometimes called monkfish, although this name is also applied to members of the genus Lophius. While some species occur over a wide geographic range, the majority are restricted to a smaller area. Restriction in geographic range might be as a result of the behavior of Squatina species, which are ambush predators with a corresponding stationary bottom-dwelling habit. Thus, trans-ocean migration is extremely unlikely, even though large-scale coastal migratory patterns have been reported in species such as S. squatina. While the forward part of the angel shark's body is broad and flattened, the rear part retains a muscular appearance more typical of other sharks. The eyes and spiracles are on top and the five gill slits are on its back. Both the pectorals and the pelvic fins are large and held horizontally. There are two dorsal fins, no anal fin and unusually for sharks, the lower lobe of the caudal fin is longer than the upper lobe. Most types grow to a length of 1.5 m (5 ft), with the Japanese angel shark, known to reach 2 m. While they may grow very large, some angel sharks develop spinal abnormities which include scoliosis. Landings of Pacific Angel Shark increased through the mid-1980s and reached over 1125 tonnes in 1986, becoming the shark species with the highest total reported landings off the US West coast that year. Angel sharks possess extensible jaws that can rapidly snap upwards to capture prey and have long, needle-like teeth. They bury themselves in sand or mud lying in wait for prey, which includes fish, crustaceans and various types of mollusks. They are ovoviviparous, producing litters of up to 13 pups. Pacific Angel Shark pups are born from March to June in deep water — generally 180 to 300 feet (55 and 90 metres) — possibly to protect the tiny pups from predators. Angel Sharks usually reside in depths of 1–200 m and can be seen on muddy or soft bottom substrata where they can easily blend in as they lie on the bottom. Areas with the greatest habitat suitability consist of ideal temperature, chlorophyll, salinity, and depth levels. Since Members of the family Squatinidae have a unique camouflage method, it goes hand in hand with how they obtain their food, by lying still on the sea floor, making rapid lunges at passing prey,and using negative pressure to capture prey by sucking it into their mouths. Morphological identification in the field can be difficult due to discontinuity and similarity of species. In this specific circumstance, the sharks' place within the class Squatina comprises three species in the southern part of the western Atlantic. The three species observed were Squatina Guggenheim, S. occulta and the Brazilian guitarfish Pseudobatos horkelii. These three species are listed in the IUCN Red List as threatened, and they are now protected under Brazilian law, which makes angling and exchange illegal. To prevent landing and trade of these endangered specie along the Sao Paulo, DNA barcoding was used. DNA barcoding revealed fishing and trafficking of these protected species. Although this shark is a bottom-dweller and appears harmless, it can inflict painful lacerations if provoked, due to its powerful jaws and sharp teeth. It may bite if a diver approaches the head or grabs the tail. Angelsharks have a unique way of breathing compared to most other benthic fish. They do not pump out water from the oropharyngeal cavity like other fish. Instead they use gill flaps located under their body to pump out water during respiration. Doing so also allows them to be more discreet and prevent detection.