White-fin Swellshark

About the White-fin Swellshark

The Whitefin Swellshark is a species of catshark, belonging to the family Scyliorhinidae, endemic go Southeastern Australia.

Biology and Description:

The Whitefin Swellshark is a stocky species measuring up to 1.1 m long. The head is short, wide and flattened with a rounded snout. The eyes are positioned high on the head followed by tiny spiracles. The mouth is large and arched and the nostrils are preceded by expanded skin flaps. There are around 90-116 upper tooth rows and 97-110 lower tooth rows; each tooth has three central cusps. The first dorsal fin is rounded and originates over the pelvic fin. The second dorsal fin is much smaller and triangular, originated over the anal fin. The pelvic fins are small, males have long claspers. The large caudal fin has a distinct lower lobe and a deep ventral notch near the tip.  Like other members of its genus, the Whitefin Swellshark can swallow water or air to increase its girth as a defence against predators. Its reproduction mode is oviparous; the eggs are enclosed in smooth flask-shaped capsules. Maturity in males and females is reached at 70 cm and 98 cm respectively. Males reach maximum size at 101 cm TL and females at 102.5 cm TL.

Habitat:

The Whitefin Swellshark is found off southeastern Australia from Batemans Bay, New South Wales as far as Western Australia, including Tasmania. It is a bottom dweller that inhabits the outer continental shelf and the upper continental slope at a depth of 126 – 554 m.

Conservation:

The area inhabited by the Whitefin Swellshark is subject to high fishing pressure. Because this is a bottom-dwelling species, this shark is susceptible to capture by trawlers and is a common component of trawl bycatch off southern Australia. As a result, the International Union for Conservation of Nature has assessed this species as Near Threatened and recommend close monitoring. There are no current conservation actions in place for this species.  

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