Recently discovered angel shark in eastern Australia
Family: Squatinidae – Angel Sharks
Common Name– Angel Sharks or Angelsharks
Average Size and Length: They are born around 11.8 inches. Mature males are measured at 3 feet and mature females at 3.5 feet. The maximum recorded for a male is 110 cm/ 3.6 feet and 4.3 feet for a female.
Average Weight: The maximum published weight is 17 kg/ 37 pounds.
Teeth and Jaw: The mouth is very wide and placed terminally. They have expendable necks and trap-like jaws that can rapidly snap upwards and hinge shut. They have long, needle-like teeth in the upper and in the lower jaws used for gripping.
Head: The head is broad and extended laterally and strongly depressed. They have a very short snout. The nasal barbels have extended tips and lobate fringes. There are low lateral head folds. There is a concave interorbital space between the eyes. The spiracles are close to the eyes and are wider than eye-length.
Denticles: There are heavy orbital thorns which can be distinguished from Squatina australis, the Australian angelshark. There are strong orbital thorns. No medial row of predorsal thorns are shown. There are dermal denticles densely covering the entire dorsal surface of the body.
Tail: The tail is strongly depressed and even at the origin of the caudal fin.
Demographic, Distribution, Habitat, Environment and Range: The Eastern angelshark can be found in eastern Australia between Cairns, Queensland and Lakes Entrance, Victoria (17°S – 38°S). They can be found on the outer continental shelf and upper slope between 427-1,033 feet. They are considered benthopelagic and can be found in sand or mud. Occasionally they can be found up to 197 feet.
Diet: They probably feed on bony fishes, crustaceans, and cephalopods.
Ram-Suction Index: They have an RSI more towards the suction end of the scale. They lay flat and still on the bottom, when the time comes, they lung at prey and suck it into their mouths with negative pressure.
Aesthetic Identification: The body of the Eastern angelshark is robust and strongly depressed anteriorly and firm. The trunk is similarly depressed and deepest over the abdomen. The abdomen is moderately elongated. They are almost ray-like or skate-like. They look like they have the wings of an angel. The Eastern angelshark is a yellow-brown to a chocolate-brown and has dense patterns of small white dark edged symmetrical spots. They also have many large brownish blotches. It has a white nuchal spot with no ocelli. They also have light unspotted unpaired fins. There is no tapering abruptly at pelvic-fin insertion. The pectoral fins are very large, expanded at the base and very fleshy. The pelvic fins are large and elongated. The dorsal fins are similar in size and shape, somewhat upright and close together.
Biology and Reproduction: They are more than likely ovoviviparous having up to 20 pups per litter.
Vertebrae: 134 – 139.
Behavioral Traits, Sensing and Intelligence: The Eastern angelshark is lethargic by day and lies buried still in the mud or in the sand mud with only their eyes distended out, waiting to ambush prey.
Eastern angelsharks have a unique way of breathing compared to most other benthic sharks and fish. They do not pump out water from the oropharyngeal cavity. Instead, they use gill flaps located on the sides of their body to pump out water during respiration. Doing so also allows them to be more unnoticeable and prevent detection from unwanted predators.
Eastern Angelshark Recorded Attacks on Humans: Eastern angelsharks aren’t dangerous to humans unless provoked. Because of their powerful jaws and sharp teeth, they can inflict injury on anyone or anything that may pose a threat to them. There have been cases of Angel sharks biting divers that have tried to restrain them, approach too close to the head, corner them, or grab their tails.