longcomb sawfish or narrowsnout sawfish or green sawfish

Critically endangered sawfish over 20 feet long

The Longcomb sawfish, Narrowsnout sawfish or Green sawfish (Pristis zijsron) is a species of sawfish in the family Pristidae, found in tropical and subtropical waters of the Indo-West Pacific. It is more than likely the longest species of sawfish, reaching lengths of 24 feet in the past; however, today they are usually around 20 feet in length. It may live more than 50 years.

 

Family: pristidae – sawfish

Genus: Pristis 

Species: zijsron

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

SubclassElasmobranchii

Super Order– Batoidea

OrderRhinopristiformes

Common Name– Rays

Family– Pristidae

Common NameSawfish

GenusPristis

Specieszijsron

Status: IUCN Red List CRITICALLY ENGANGERED

Average Size and Length: The Longcomb sawfish reaches a total length of up to 24 feet, but rarely more than 20 feet.

Teeth and Jaw: The Longcomb sawfish has teeth near the base of the rostrum (unlike the Knifetooth sawfish). It has 23–37 teeth on each side of the rostrum (18–24 in the Dwarf sawfish, 20–32 in Smalltooth sawfish, and 14–24 in Largetooth sawfish). The teeth towards the tip of the rostrum are closer to each other than those at its base (unlike the Dwarf, Smalltooth and Largetooth sawfish where either equally spaced or only marginally closer to each other towards the tip of the rostrum).

Head: The rostrum is narrow with a width equaling 9%–17% of its length (typically wider in Dwarf and Largetooth sawfish) and is 23%-33% of its total length (20%–25% in Dwarf sawfish).

Tail: The Longcomb sawfish has a very small or no lower tail lobe (there is one present in the Knifetooth and Largetooth sawfish).

Demographic, Distribution, Habitat, Environment and Range: The Longcomb sawfish can be found in tropical and subtropical waters in the western and central Indo-Pacific. Historically its distribution covered over 2,300,000 square miles and it ranged from South Africa, north to the Red Sea and Persian Gulf, east to the South China Sea, through Southeast Asia to Australia. In Australia, it ranged from Shark Bay, along the northern part of the country, and south to Jervis Bay on the eastern coast. Nowadays, it has disappeared from much of its past range. It can live in colder waters than its relatives.

The Longcomb sawfish is mainly found in coastal marine, mangrove and estuarine habitats, even in very shallow waters, but can also be found far offshore to a depth of more than 230 feet. Some records confirm that the Longcomb sawfish will inhabit rivers far inland, but this is out of the ordinary. It prefers sandy, silty or muddy bottoms.

Check out this interactive map courtesy of the Florida Museum, a University of Florida accredited resource. 

Diet: The Longcomb sawfish feeds on fish, crustaceans and mollusks.

Longcomb sawfish can fall prey to large sharks and crocodiles.

Aesthetic Identification: The Longcomb sawfish is greenish-brown to olive above, while counter-shaded whitish below. It has short pectoral fins (unlike the Knifetooth and Largetooth sawfish), a leading edge of the dorsal fin that is located behind the leading edge of the pelvic fins (in front of in Largetooth sawfish and above in Smalltooth sawfish).

Biology and Reproduction: The Longcomb sawfish is ovoviviparous. The young are between 2 and 3.5 feet long at birth. Research suggests that there are around 12 young in each litter, but this is unconfirmed. Other sawfish species range from 1 to 20 on each litter size.

Females give birth in inshore areas, and the young stay near the coast and in estuaries in the first part of their lives. Sexual maturity is reached at an age of about 9 years, and a length of 11–12 feet. The maximum age is unknown, but it might be in surplus of 50 years. One Longcomb sawfish was caught young, and kept in an aquarium and lived for 35 years.

Behavioral Traits, Sensing and Intelligence: The Longcomb sawfish whips its rostrum from side-to-side to dislodge prey from the seabed and to stun groups of fish.

Longcomb Sawfish Future and Conservation: The Longcomb sawfish has declined radically and is listed by the IUCN as “Critically Endangered”. Both the fins and the saw are highly valuable. The fins of the Longcomb sawfish are used for shark fin soup and the saw as a novelty item. In Asia, some parts are used in traditional medicine, and the meat is consumed.

Fishing is the main threat, but it is also threatened by habitat loss. Some ignorant humans fear its saw, and therefore kill it before it is even brought onboard. The saws are susceptible to to becoming tangled in fishing nets.

Small numbers are kept in public aquariums listing a total of 13 individuals (7 males, 6 females) in North America in 2014, 6 individuals (3 males, 3 females) in Europe in 2013, and 2 individuals in Japan in 2017.

Longcomb Sawfish Recorded Attacks on Humans: Not a threat to humans. It will however defend itself by thrashing its saw back and forth if caught. This will cause injury.