Sawshark

Lore & Background

Sawsharks have a pair of long barbels about halfway along the snout, two dorsal fins, and lack anal fins. The genus Pliotrema has six gill slits, while Pristiophorus has five. Their rostral teeth typically alternate between large and small. The body is covered in tiny placoid scales, and coloration—often yellow-brown with dark spots—helps them blend with the sandy ocean floor. Females tend to be slightly larger than males. These sharks feed on small fish, squid, and crustaceans. The function of the barbels is not well understood, nor is the exact method of using the rostrum; it may be used in side-to-side swipes to cripple prey, or defensively. The saw is covered with ampullae of Lorenzini, sensory organs that detect electric fields from buried prey. Sawsharks are ovoviviparous, with eggs hatching inside the mother; pups are born at 30 cm after 12 months, with rostral teeth angled backward to avoid harming the mother. Life expectancy is poorly understood but thought to be 10 years or more. Sawsharks are found in many areas worldwide, most commonly from the Indian Ocean to the southern Pacific Ocean. They are normally at depths of 40–100 m, but can be found much lower in tropical regions. Mating season occurs seasonally in coastal areas, with litters of 3–22 pups every 2 years.

Reader's Guide

Sawsharks represent a distinct order of sharks, Pristiophoriformes, notable for their elongated, tooth-edged rostrum that sets them apart from other elasmobranchs. Their significance lies in their unique morphology and sensory adaptations, including barbels and ampullae of Lorenzini, which allow them to detect buried prey. Despite their distinctive appearance, much of their life history remains poorly understood, including how they use their saw and the function of their barbels. The ten known species are distributed across two genera, with fossil genera also known from the Eocene to Pleistocene of New Zealand, Late Miocene of Chile, and Late Cretaceous of Lebanon. Their conservation status and limited interaction with humans underscore the need for further research into their ecology and population dynamics.

Did You Know?

• Sawsharks have a pair of long barbels about halfway along the snout.
• The saw is covered with ampullae of Lorenzini that detect electric fields from buried prey.
• Pups are born at 30 cm after 12 months of pregnancy, with rostral teeth angled backward to avoid harming the mother.

Common Misconceptions (Editorial)

Some people mistake sawsharks for sawfish, but they are distinct: sawsharks have barbels on their snout and gill slits on the side of the head, while sawfish lack barbels and have gill slits on the underside. Another common misconception is that sawsharks use their saw primarily for digging or stirring sediment; however, the facts indicate the rostrum may be used in side-to-side swipes to cripple prey or defensively, and the exact method is not well understood.

Why It Matters (Editorial)

Sawsharks endure as a compelling example of evolutionary specialization, with their unique saw-like rostrum and sensory barbels allowing them to thrive in ocean-floor environments. Understanding these often-misunderstood creatures helps highlight the diversity of shark adaptations and the importance of protecting deep-sea habitats where many remain poorly studied.