Sawback Angelshark

About the Species

The sawback angelshark is a cartilaginous fish. The species once occurred in waters throughout the central and western Mediterranean Sea and along the eastern Atlantic, from Morocco to Angola. It no longer occurs in many areas of the Mediterranean, including the Adriatic and central Aegean Sea, and is rare throughout the rest of its range. The main threat to the sawback angelshark is commercial fishing, particularly by demersal fisheries (for example, trawl fisheries) that primarily operate in depths where the sawback angelshark occur. In 2016, NOAA Fisheries listed the species as endangered under the Endangered Species Act.

Appearance

Angelsharks are recognized by their batoid shape (similar to a ray or skate). The sawback angelshark can be distinguished from other angelsharks by its row of dorsal spines (sword-like bony structures) down the middle of its body, with spines also located on the snout and above the eyes.

Behavior and Diet

Sawback angelsharks are ambush predators, meaning they lie in wait for prey to pass closely overhead before attacking. They eat small sharks and bony fishes along with benthic invertebrates, including cephalopods and crustaceans.

Where They Live

Sawback angelsharks are found in continental shelf and upper slope sediment habitats in the Mediterranean Sea and eastern Atlantic, but has never been recorded in Atlantic waters north of the Strait of Gibraltar. These sharks are nocturnal bottom dwellers, occurring in depths of 98 to 1640 feet, and prefer to spend most of their time buried in the sand or mud during the day.

Lifespan & Reproduction

Little is known about the growth and reproduction of sawback angelsharks. The species displays sexual dimorphism, with females reaching larger sizes than males of the species. Female sawback angelsharks give birth to live young, with a gestation period that likely lasts around a year. Litter sizes range from 8 to 12 “pups.”

Threats

Commercial and artisanal fishing

The primary threat to the sawback angelshark is overutilization in commercial and artisanal fisheries, particularly demersal fisheries (e.g., trawl fisheries). Historically, angelsharks were so common that fishermen developed a special net designed specifically for catching them. However, over the last 50 years, significant population declines in angelsharks have been observed, with these declines coinciding with the start of trawling activities in the northeast Atlantic and Mediterranean. Because angelsharks are sedentary, bottom-dwelling species, they are highly susceptible to being caught in demersal and trawl fisheries. Consequently, as these fisheries expanded with the use of steam-powered trawlers in the 1890s, angelsharks began to suffer significant declines in abundance throughout their historical range. Evidence of illegal fishing operations have also contributed to declines in sawback angelshark populations. The species is now considered to be extirpated from the Adriatic Sea, central Aegean Sea, Ligurian and Tyrrhenian Seas, off the Balearic Islands and in the Catalan Sea, and is considered rare throughout the rest of its range in the northeast Atlantic and Mediterranean. Because the demersal fisheries that historically contributed to the decline in S. aculeata are still active throughout the species’ range, and primarily operate in depths where these angelsharks occur, the species remains at risk of overutilization.

Scientific Classification

Kingdom	Animalia
Phylum	Chordata
Class	Chondrichthyes
Order	Squaliformes
Family	Squatinidae
Genus	Squatina
Species	aculeata