- A-Z Animals
The frilled shark is a “living fossil”, owing to its primitive physical features and lack of evolutionary changes over the years. Its common name comes from its gill slits which form a fleshy frill.
German naturalist Ludwig Doderlein discovered the first frilled shark, but his findings were lost. So, the official documentation of this species fell to American zoologist Samuel Garman, who named it in 1884. The last part of its scientific name, anguineus, means snake-like or eel-like in Latin.
Size: Length- Males: 5.6 ft (1.7 m) Females: 6.6 ft (2.0 m)
Teeth: The jaws hold over 300 teeth, shaped like miniature tridents. There are 19-28 rows of teeth in the upper jaw, while the lower jaw holds 21-29 rows.
Fins: Frilled sharks haveshort, round pectoral fins and a small dorsal fin with a rounded margin positioned opposite their anal fin. The large broad anal, and pelvic fins, also appearing round like the other fins, lie at the tail end of their body. The caudal fin is huge, triangular in shape, and covered in scales.
Body and Coloration: They have a slender, elongated body giving them an eel-like appearance, alongside a broad, flat head and a short, round snout. Their eyes are relatively large without any protective membrane. These sharks have two slits close to their eyes, functioning as nostrils. There are six gill slits near the throat, with the first one forming a collar and the last five creating a fleshy frill.
They mostly have a chocolate brown appearance, lighter on their undersides.
Though seen worldwide, details of its exact distribution remain unrecorded. Specimens have been found in different locations, including southeast Japan, New Zealand, eastern Australia, Norway, western Ireland, northern Scotland, northern Namibia, northern Chile, South Africa, and southern California.
Like most other deep-sea sharks, the frilled shark is found close to the continental shelf at around a depth of 1640 – 3280 ft but may also dwell at 4900 ft.
They primarily consume cephalopods (mainly squids) and smaller sharks that form 60% of their diet. Other forms of prey include bony fish and sea slugs.
Their estimated lifespan is 25 years.
Do They Attack Humans
They hardly come in contact with humans since they inhabit greater depths. Hence these sharks pose no threat to them.
There are few known predators of the frilled shark, but larger shark species most likely threaten them.
Like all other sharks, the frilled shark undergoes internal fertilization, meaning the male uses his claspers to inject his sperm into the female’s cloaca. There is no seasonal mating period as weather changes on the ocean’s surface do not affect the deep sea.
A litter consists of 2-15 pups, born after a long gestation period of up to 3.5 years. Initially, at birth, the young sharks measure around 15-24 inches in length. Male juveniles reach sexual maturity at 3.3–3.9 ft (1.0–1.2 m), while for females, it’s 4.3–4.9 ft (1.3–1.5 m).
The IUCN lists the frilled shark as “LC” or “Least Concern”. It was initially listed as “Near Threatened” due to the risk caused by overfishing done in their habitat as well its slow reproduction rate, but it was later re-classified to “LC”.
The New Zealand Threat Classification System classified this shark as “At Risk – Naturally Uncommon” in 2018. This is primarily due to the shark’s rarity, making it hard to detect their exact population in the wild.