The Whitefin swellshark (Cephaloscyllium albipinnum) is a species of catshark, belonging to the family Scyliorhinidae, endemic to southeastern Australia. They can be found on the outer continental slope between 787-1.804 feet. They are critically endangered because of their limited range and that they are taken as bycatch. Like other members of its genus they can inflate their stomachs with water or air to ward off potential predators.
Family: Scyliorhinidae – Catsharks
Genus: Cephaloscyllium
Species: albipinnum
Phylum– Chordata
Class– Chondrichthyles
Common Name– Ground Sharks
Family– Scyliorhinidae
Common Name– Catsharks
Genus– Cephaloscyllium
Species– albipinnum
Status: IUCN Red List CRITICALLY ENDANGERED
Average Size and Length: An egg case measures 11×5 cm. Mature males measure at 70 cm/2.3 feet, and the maximum is at least 94 cm/3.1 feet.
Current Rare Mythical Sightings: In 1994, the Whitefin swellshark was identified as a new species and known provisionally as Cephaloscyllium “sp. A“, until it was formally described by Peter Last, Hiroyuki Motomura, and William White, in a 2008 Commonwealth Scientific and Industrial Research Organisation (CSIRO) publication. Its specific epithet albipinnum comes from the Latin albi meaning “white”, and pinna meaning “fin”, referring to its distinctive white fin margins. The type specimen is a 3.3-foot-long adult male caught near Maria Island, Tasmania.
Teeth and Jaw: The mouth is large and arched, without furrows. The teeth have 3-5 cusps near symphysis of upper jaw. There are 90–116 upper tooth rows and 97–110 lower tooth rows. Each tooth has three central cusps and often 1–2 additional small, lateral cusplets. The upper teeth are exposed when the mouth is closed.
Head: The head is short, broad and flattened, it is between 8.6-13.5% of the total length in height. The snout is broadly rounded its length is between 48.1-52.4% of the total length. There are ridges over the eyes. The slit-like eyes are positioned high on the head, and are followed by tiny spiracles. The nostrils are preceded by laterally expanded flaps of skin that do not reach the mouth. Prenarial is between 4.5-5.1% of total length, in length. The length of the preorbital snout is between 1.4-1.7 times the prenarial length. The width of the nostril is between 2.4-2.7% of the total length. The eye-spiracle space is wide, between 1.0–1.4% of the total length.
Denticles: The skin is thick and rough. There are widely spaced, arrowhead-shaped dermal denticles with three horizontal ridges. There are mainly weak tricuspidate flank denticles. The back is without greatly enlarged denticles.
Tail: The caudal fin is large and has a distinct lower lobe and a deep ventral notch near the tip of the upper lobe.
Demographic, Distribution, Habitat, Environment and Range: The Whitefin swellshark can be found in southeastern Australia from Batemans Bay, New South Wales to the Great Australian Bight as far as Eucla, Western Australia, including southern Tasmania from Maria Island to Point Hibbs, on the upper continental slope between 787-1.804 feet. They are considered temperate bathypelagic.
Ram-Suction Index: Like other members of their genus, they more than likely are high on suction.
Aesthetic Identification: The Whitefin swellshark is large and stalky with a thick body. They have a pattern of broad dark blotches and saddles on a medium greyish or brownish background on the sides and back, which is less apparent in juveniles. They usually have 5 pre-dorsal bars. The fins are mostly dark above with pale margins, and the ventral side is pale. The fourth and fifth pairs of gill slits lie over the pectoral fin bases and are shorter than the first three. The pectoral fins are large and broad, with gently concave posterior margins. It is between 2.5-3.1 in prepectoral length, and between 6.3-6.9 in pre-pelvic length. The first dorsal fin is rounded and originates over the forward half of the pelvic fin bases. The second dorsal fin is much smaller and somewhat triangular, originating over the anal fin. The pelvic fins are small. Males have very long claspers, up to 8.8% of the total length, almost reaching anal fin. The anal fin is larger than the second dorsal fin and is rounded in juveniles, becoming more angular in adults. The interspace about 4.4 in anal-fin base. The trunk is between 16.1-23.8% of the total length in width. The pectoral fin is large, its height is between 12.6-13.6% of the total length. The posterior margin is between 12.0-13.6% of the total length, in length. The anal fin is tall, its height is between 3.8–4.4% of the total length. The anal-caudal space is between 4.0-5.6%. The precaudal length is between 74-78% of the total length. The interdorsal space is between 6.3-7.6% of the total length.
Biology and Reproduction: They are oviparous. The egg cases are purse-shaped or flask-shaped with flanged edges and short horns at the corners that support long, coiled tendrils, and are not ridged. They are light yellowish in color. Other than that, the reproduction is poorly known.
The vertebral centra is between 121-126.
Behavioral Traits, Sensing and Intelligence: Like other members of their genus, they inflate by swallowing water or air (on the surface) to deter predators by increasing its size.
Speed: They are possibly sluggish while swimming.
Whitefin Swellshark Future and Conservation: They are critically endangered. They are taken as bycatch by trawlers, and their limited range is declining.
The Australian South East Trawl Fishery, which operates off New South Wales, over a third of this shark’s range reported that its catch rate dropped over 30% between 1967–77 and 1996–97. The South East Trawl Fishery Observer Program off southern Australia has also reported a slight population decline.
Whitefin Swellshark Recorded Attacks on Humans: Not a threat to humans.