Family: Squatinidae – Angel Sharks
Common Name– Angel Sharks or Angelsharks
Average Size and Length: They reach at least 2.1 feet. It is possible that one was reported at 114 cm/ 3.7 feet.
Teeth and Jaw: They have expendable necks and trap-like jaws that can rapidly snap upwards and hinge shut. They have long, but small, needle-like teeth in the upper and in the lower jaws used for gripping.
Head: The head is broad, and extends laterally. The snout is very short. The nasal barbels have expanded tips and lobate fringes. There is a concave interorbital space between the eyes.
Demographic, Distribution, Habitat, Environment and Range: The Western angelshark can be found in western Australia. They can be found on the tropical outer continental shelf and uppermost slope between 427-1,017. They are considered benthopelagic.
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 Western angelshark differs from the Ornate angelshark in the color and the patterns. The body shape is that of a skate or a ray, it is vertically compressed with large pectoral and pelvic fins that extend forward. They have the appearance of wings. The dorsal surface is pale to medium brownish or greyish. The pattern is widely spaced blue spots and brown blotches. There are no symmetrical small white spots or ocelli, but instead, a single small white nuchal spot. There are light unpaired fins without dark spots.
Biology and Reproduction: Not much is known about the biology or reproduction of the Western angelshark. They are presumably ovoviviparous. Some suggest they can have up to 20 pups per litter, but this is unconfirmed. It is suggested that males may mature at 75 cm/ 2.5 feet, but this is not confirmed.
Behavioral Traits, Sensing and Intelligence: The Western angelshark lies semi-buried in the sand or on the muddy bottom waiting and ready to ambush prey. They can remain still on the bottom for extremely long and extended periods of time. Research suggest their behavior changes at night, and they are nocturnally active.
Western 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.
Western Angelshark Future and Conservation: There is very little commercial fishing within its range, so they are stable and of least concern currently. There are some areas of Western Australia’s North Coast Bioregion that are closed to trawl fishing through spatial management arrangements and since 2009, there has been a decrease of the quota from the Pilbara Fish Trawl Fishery.
Western Angelshark Recorded Attacks on Humans: Western 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.