Pristiophoriformes

## Defining Features

Also known as "Sawsharks", Pristiophoriformes are characterized by flattened snouts that have a row of thin, loosely attached teeth along the edge. Pristiophoriformes typically have 5 or 6 pairs of gill slits located on the side of their heads. Pristiophoriformes have spiracles, which are additional breathing apparatuses which take in water to ventilate the gills, behind their eyes. They are oviparous.

## Habitat and Range

Sawsharks are usually found in the deep waters off the coast of the Pacific and Indian oceans. Most Pristiophoriformes tend to be found between 40-100 m, but some species in the Bahamas can be found between 640-914 m. Some types of sawsharks can move up and down the water column in response to temperature changes. They are also mostly found in temperate, subtropical and tropical ocean climates.

## Fisheries Conservation and Concern

Sawsharks are overall not a very threatened order, and have no real ongoing conservation projects. There are some particular species, such as the Lana's Sawshark, which are near threatened due to overfishing as well as harvesting of aquatic resources. There are also a couple species, such as the Kaja's Sixgill Sawshark, where there isn't enough information or research on the shark to determine conservation status.

## Example Species in Pristiophoriformes

### **Common Sawshark**

#### ***Pristiophorus cirratus***

Defining Features: The common sawshark, or longnose sawshark, is a slender species of shark with an average length of around 125 cm. It is white on its underside and either gray or brown on top with two brown stripes running along either side of the snout. It has a large mouth with rows of small teeth along with 19 to 25 larger teeth on each side of its mouth. It has a pair of barbels which are closer to the tip of its snout than they are to its mouth.

Range & Habitat: The common sawshark is found in temperate waters off the coast of southern Australia. It resides in continental shelf and slope waters at depths between 100 and 650 meters.

IUCN Concern: The common sawshark is listed as being of least concern, though it is sometimes caught as bycatch.

### Lana's Sawshark

#### *Pristiophorus lanae*

Defining Features: Lana's sawshark is a recently discovered species of shark named for its Dave Ebert's (its discoverer) shark-loving niece. The few sharks found have been pretty small, all being around 75 cm in length. The species has a relatively long snout with barbels closer to its mouth than to the tip of its snout. It has a brown top and white underside.

Range & Habitat: Lana's sawshark has only ever been found off the coast of the Philippines, but researchers suspect that its range may extend around Southeast Asia. The shark is found in tropical waters at depths between 230 and 590 m.

IUCN Concern: Lana's sawshark is listed as near threatened by the IUCN. It may be occasionally caught as bycatch, but very few Lana's sharks have been found so its difficult to estimate their numbers or find out why their numbers may be decreasing.

## References

Saw Shark Facts: Thoughtco.com

Chondrichthyan Tree of Life: sharksrays.org

Pristiophoriformes: Elasmo-research.org

Fishbase: https://www.fishbase.in/summary/67529

Australian Museum: https://australian.museum/learn/animals/fishes/common-sawshark-pristiophorus-cirratus/

IUCN Redlist: https://www.iucnredlist.org

California Academy of Sciences: https://www.calacademy.org/explore-science/lana’s-sawshark