Common sawshark

Pristiophorus cirratus

FAMILY

Pristiophoridae

TAXONOMY

Pristis cirratus Latham, 1794, Australia (Port Jackson, New South Wales).

OTHER COMMON NAMES

English: Longnose sawshark; French: Requin scie à long nez; Spanish: Tiburòn sierra trompudo.

PHYSICAL CHARACTERISTICS

Common sawsharks are uniquely pigmented, with a reddish brown background pattern; numerous irregular darker brown saddles along the trunk, fins, and head; dark brown stripes across rostral saw; as well as numerous small spots (smaller than the eye) scattered on body; the rostral spines have dark margins. Ventrally uniform creamy white. Rostral saw is relatively long and slender when compared to the other Australian species, P. nudipinnis, and the rostral barbels are located at about the center of the rostral saw, as opposed to slightly closer to the eyes as in the latter species.

DISTRIBUTION

Common sawsharks occur off southern and western Australia (reaching to about 30°S), including around Tasmania.

HABITAT

These sharks are found on the continental shelf and upper slope, from 131–1,017 ft (40–310 m), usually on sandy bottoms. They are also reported to occur in bays and estuaries, but are believed to be more abundant from 121–479 ft (37–146m). Although present in the same general area as P. nudipinnis, P. cirratus apparently occupies deeper waters.

BEHAVIOR

Common sawsharks are believed to form schools (perhaps for feeding) and are abundant in trawls for benthic fishes. This species has been filmed swinging its saw from side to side in an attempt to injure small fishes. They commonly rest on the bottom, with the rostral saw slightly elevated and supported in a tripodlike stance by the rostral barbels. Common sawsharks are not frequently observed in the wild.

FEEDING ECOLOGY AND DIET

These sharks feed on fishes, including cornetfishes (Fistulariidae), and on invertebrates, particularly crustaceans.

REPRODUCTIVE BIOLOGY

Mostly unknown, but they are reported to breed during winter months. Their size at birth is about 15 in (38 cm), and males are sexually mature at about 3.3 ft (1 m) in length.

CONSERVATION STATUS

These fishes are listed as Lower Risk/Near Threatened by the IUCN.

SIGNIFICANCE TO HUMANS

Common sawsharks are captured as bycatch by trawlers and are available regularly in fish markets. The flesh is reported to be very good. The elongated rostral saw is sometimes coveted for its value as an ornament. ◆