Angel sharks grow up to and can weigh around , While the anterior part of the angel shark's body is broad and flattened, the posterior part retains a muscular appearance more typical of other sharks. The eyes and
spiracles are dorsal and the five
gill slits are on its back. Both the pectoral and
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. Some angel sharks have deformities that have been described in elasmobranchs. These can include skeletal deformities, as lateral spinal curvature (scoliosis), humpback curvature (khyphosis), axial spinal curvature (lordosis), missing fins, additional fins, deformed snout, and more. These abnormalities have only been found in a few sharks, but the causes of these deformities have been found to be from dietary nutritional imbalance, genetic factors, parasites, traumatic injuries, or stress in the specimen. In 2015, two sharks were captured and examined, and both showed a lateral spinal curvature (scoliosis) and also a humpback curvature. Both the animals had the curvature in the middle of their pectoral fins, but the deformity did not affect their swimming capacity. Landings of Pacific angel shark increased through the mid-1980s and reached over 1,125 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 loose sediment 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 pups from predators. Angel sharks usually reside in depths of and can be seen on muddy or soft benthic substrata where they can easily blend in as they lie in wait. Members of the family Squatinidae have a unique camouflage method, which relates to how they obtain their food, involving 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. ==Species analysis==