SOUTHERN AFRICAN FRILLED shark

Mythical, serpent-looking shark with a frilled appearance

The Southern African Frilled shark (Chlamydoselachus africana) is a species of shark in the family Chlamydoselachidae, described in 2009. It is found in the deep waters off southern Angola to southern Namibia. It is difficult to distinguish from the more well-known Frilled shark (C. anguineus) but is smaller at maturity and differs in several proportional measurements including head length and mouth width.

 

Family: Chlamydoselachidae – Frilled sharks

Genus: Chlamydoselachus 

Species: africana

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

SubclassElasmobranchii

OrderHexanchiformes

Common Name– Cow and Frilled Sharks

Family– Chlamydoselachidae

Common Name– Frilled Sharks

GenusChlamydoselachus

Speciesafricana

Status: IUCN Red List NOT EVALUATED

Average Size and Length: The largest known female is the immature 46-inch-long holotype, and the largest known males measure 39 inches long.

Current Rare Mythical Sightings: The existence of a second Chlamydoselachus species off southern Africa was first suspected from a specimen caught off Lüderitz, Namibia in February 1988, by the South African research ship FRS Africana (after which this species would eventually be named). The specimen was an adult male smaller than other known mature C. anguineus, and subsequent investigations revealed other consistent differences between frilled sharks in this region and C. anguineus. The new species was termed Chlamydoselachus “sp. A”, before being formally described in 2009 by David Ebert and Leonard Compagno, in a paper for the scientific journal Zootaxa. The holotype was a 46 inches long immature female caught at a depth of 1,342 feet off the Cunene River, Namibia, by the research vessel Benguela.

Teeth and Jaw: The sizable mouth of the Southern African Frilled shark is placed terminally on the blunt snout, containing around 30 tooth rows in the upper jaw and 27 tooth rows in the lower jaw. Each tooth has 3 slender, smooth, recurved cusps, with tiny cusplets between them, and a base that interlocks with the tooth behind it.

Head: It has a broad, flattened head, with eyes are large and rounded.

Compared to the Frilled shark, the Southern African Frilled shark has several proportional differences, including a longer head and gill slits, more widely spaced eyes and nares, broader mouth.

Tail: The caudal fin is low and somewhat triangular, without a lower lobe.

Demographic, Distribution, Habitat, Environment and Range: The Southern African Frilled shark has only been confirmed to occur from off southern Angola to southern Namibia. Frilled sharks have also been captured off South Africa, at 4,040–4,590 feet deep off Eastern Cape Province, and at 980 feet deep off KwaZulu-Natal Province; it is uncertain whether these specimens are C. africana. Little is known of its habitat preferences; one known specimen was caught 1,394 feet down in a zone of low dissolved oxygen and high nutrients, over a soft substrate.

Diet: From stomach contents, the Southern African Frilled shark seems to feed mainly on smaller sharks such as the African Sawtail Catshark (Galeus polli). Its jaws, buccal cavity, and abdomen are all highly distensible, suggesting that this shark is specialized for capturing and swallowing whole large prey, with its rows of needle-like, recurved teeth preventing escape. One 36-inch-long specimen was found to have swallowed a Ghost Catshark (Apristurus sp.) that measured 40% of its body length. (Ebert, D.A. & L.J.V. Compagno (2009). “Chlamydoselachus africana, a new species of frilled shark from southern Africa (Chondrichthyes, Hexanchiformes, Chlamydoselachidae)”.

Ram-Suction Index: Presumably similar to the Frilled shark.

Aesthetic Identification: The Southern African Frilled shark looks very similar to the Frilled shark, with a long eel or snake-like body. In life the shark is dark gray but covered with a thin membrane that gives it a uniform dark brown color. There are six pairs of long gill slits, with the first pair meeting over the throat. The pectoral fins are broad and rounded, originating just behind the sixth gill slit. The pelvic and anal fins are large with long bases and curved margins. The single dorsal fin is set far back on the body over the anal fin and has a short base.

Compared to the Frilled shark, the Southern African Frilled shark has a greater distance between the head and the pectoral fins.

Biology and Reproduction: Thought to be ovoviviparous. Males mature sexually at a length of 36 inches.

Behavioral Traits, Sensing and Intelligence: Unknown.

Speed: Presumably similar to the Frilled shark.

Southern African Frilled shark Future and Conservation: Not evaluated.

Southern African Frilled shark Recorded Attacks on Humans: Not a threat to humans.