Draughtsboard Shark: Cephaloscyllium isabella

Family: Scyliorhinidae

Common names

Draughtsboard Shark, New Zealand Carpet Shark, New Zealand Swellshark.

Binomial

cephaloscyllium isabella.

Synonyms

Cephaloscyllium isabellum, Cephaloscyllium sabella, Scyllium lima, Scyllium sabella, Squalus isabella.

Identification

A relatively large swell shark. Snout short and bluntly rounded. Brow ridges prominent. Mouth width much greater than snout length. First dorsal origin approximately level with middle of pelvic fin base. Second dorsal fin origin midway along anal fin base. Second dorsal fin slightly shorter than anal fin. Upper caudal subterminal notch well defined.

Dorsal surface greyish brown with dark brown diffuse blotches. Ventrum pale.

Size

Maximum length at leat 92cm; possibly to 150cm. Size at birth 16cm.

Draughtsboard Shark, Cephaloscyllium isabella. Aka New Zealand Carpetshark or New Zealand Swell Shark. Port Gore, Marlborough Sounds, South Island, New Zealand, South Pacific Ocean.

Conservation Status

LEAST CONCERN

The New Zealand Carpetshark (Cephaloscyllium isabella) population is listed as ‘Least Concern’ by the IUCN, but there is no evidence to support this criteria. Fishing pressure throughout its range remains high.

A 2015 assessment for New Zealand’s chondrichthyans by Ford et al noted that this species is one of two species with the highest risk from fishing on account of intensive fishing across its entire range year round

Habitat

Temperate water on sandy substrates, rocky reefs, and kelp. From close inshore to 690m. Mostly shallower than 400m

Distribution

Southwest Pacific Ocean. The Draughtsboard Shark is confined to the coastal waters of New Zealand.

Reproduction

Oviparous. Eggs are deposited year round, more commonly during the summer.

Diet

The New Zealand Swell Shark consumes crabs, worms, and other invertebrates. Probably also consumes bony fishes.

Behavior

Inflates its stomach by ingesting water or air as a threat response.

Reaction to divers

Easy to approach when resting on the reef. Not known to respond to chum.

Diving logistics

Encounters with New Zealand Carpetsharks are relatively common at numerous dive sites around New Zealand, but sightings are generally more common towards the south end of the country.

The General Lermontov wreck in Marlborough Sounds is a reliable spot to see this species. Other reputedly good places to look for draughtsboard sharks include the Horoirangi Marine Reserve near Nelson, and at dive sites in Fiordland.