The largetooth sawfish (Pristis microdon), also known as the Leichhardt's sawfish or freshwater sawfish, is a sawfish

Sawfish

Sawfish, also known as the Carpenter Shark, are a family of rays, characterized by a long, toothy nose extension snout. Several species can grow to approximately . The family as a whole is largely unknown and little studied...

 of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Pristidae, found in shallow Indo-West Pacific

Indo-Pacific

The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...

 oceans between latitude

Latitude

In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...

s 11° N

11th parallel north

The 11th parallel north is a circle of latitude that is 11 degrees north of the Earth's equatorial plane. It crosses Africa, the Indian Ocean, South Asia, Southeast Asia, the Pacific Ocean, Central America, South America and the Atlantic Ocean....

 and 39° S

39th parallel south

The 39th parallel south is a circle of latitude that is 39 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America....

. As its relatives, it also enters freshwater. This critically endangered

Critically endangered

Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...

 species reaches a length of up to 7 metres (23 ft). Reproduction is ovoviviparous.

Taxonomy

Considerable taxonomic confusion surrounds this species. It is part of the Pristis pristis

Common sawfish

The common sawfish, Pristis pristis, is a sawfish of the family Pristidae, found in tropical and subtropical parts of the Atlantic, Mediterranean, eastern Pacific and in northern Australia. As suggested by its name, it was once plentiful, but has now declined drastically leading to it being...

species complex

Species complex

A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...

, which also includes P. perotteti

Large-tooth sawfish

The large-tooth sawfish, Pristis perotteti, is a sawfish of the family Pristidae, found in tropical and subtropical parts of the Atlantic and east Pacific, but possibly now extirpated from most of the east Atlantic. As its relatives, it also enters freshwater, and there are records as far inland...

. P. microdon has sometimes been considered synonymous

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 with P. perotteti, and uncertainty exists over what species the scientific name P. microdon really belong to (the original description lacked a type locality).

Species description

The largetooth sawfish is a heavy-bodied sawfish with a short massive saw which is broad-based, strongly tapering and with 14 to 22 very large teeth on each side - the space between the last two saw-teeth on the sides are less than twice the space between the first two teeth. The pectoral fins are high and angular, the first dorsal fin

Dorsal fin

A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

 being mostly in front of the pelvic fins, and the caudal fin has a pronounced lower lobe.