Endangered wing-like shark hidden on the sea floor
The Argentine angelshark (Squatina argentina) is a shark belonging to the family Squatinidae. They can be found in a very limited range in the southwest Atlantic from southern Brazil to Patagonia. Due to their limited range, high commercial value, and slow reproduction rates, the Argentine angelshark is endangered. The Argentine angelshark had beautiful brown hues and patterns used in camouflage as they are ambush predators, lying motionless on the muddy bottom.
Family: Squatinidae – Angel Sharks
Common Name– Angel Sharks or Angelsharks
Status: IUCN Red List ENDANGERED
Average Size and Length: The length of the Argentine angelshark at birth is still unknown. Mature sharks are between 3.3-4 feet. Maximum recorded was 4.5 feet, but research suggests they may reach 5.6 feet.
Teeth and Jaw: The mouths of Argentine angelsharks are large. They have expendable necks and trap-like jaws that can quickly snap upwards and hinge shut. They have long, needle-like teeth in the upper and in the lower jaws used for gripping.
Head: The Argentine angelshark does not have ocelli. They have simple spatulate nasal barbels, and they have slightly fringed or smooth anterior nasal flaps with no triangular lobes on lateral head folds. The area between the eyes is concave. The eyes and spiracles are on the top of the head.
Denticles: They have enlarged thorns on the snout, but not on the back.
Demographic, Distribution, Habitat, Environment and Range: The Argentine angelshark can be found in the southwest Atlantic from southern Brazil down south to Patagonia (19°S – 53°S, 68°W – 38°W). They prefer subtropical climates and are marine demersal. They can be found on the continental shelf and upper slope between 167-1,050 feet, but typically between 394-1,050 feet down.
Diet: They typically feed on demersal fishes, shrimp, and squid.
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 Argentine angelshark is a purplish-brown color with many scattered dark brown spots that are mostly in circular groups around a central spot. There are no white spots. There are no ocelli. The dorsal fins are much paler. The body is flat and broad. The pectoral fins are large, broad, and obtusely angular with a horizontal origin, giving them the appearance of wings. The leading edge is convex forming a very distinct looking shoulder. There are two dorsal fins and no anal fin.
Biology and Reproduction: The Argentine angelshark is ovoviviparous having between 7-11 pups per litter. They have a slow reproduction rate their population doubling time is at a minimum of 14 years.
Behavioral Traits, Sensing and Intelligence: The Argentine angelshark lies buried 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.
Argentine 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 head to pump out water during respiration. Doing so also allows them to be more unnoticeable and prevent detection from unwanted predators.
Argentine Angelshark Future and Conservation: They are targeted by commercial fisheries, and are also bycatch. Due to their very low reproduction rates. Limited range, and commercial value, they are endangered and highly vulnerable.
Argentine Angelshark Recorded Attacks on Humans: Argentine 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.