Longcomb sawfish

What it is

This species is a large member of the sawfish family. It has a greenish-brown back and white underside. The most distinct feature is its long, narrow rostrum lined with teeth. These teeth extend nearly to the base of the snout. Adults can reach lengths of over seven metres, though six metres is more common today. Its pectoral fins are relatively short compared to similar species. The dorsal fin starts behind the pelvic fins. A small or missing lower tail lobe helps identify it.

Where it lives

It lives in tropical and subtropical zones of the Indo-West Pacific. Historical records show it ranged from South Africa to the Red Sea and Persian Gulf. Its territory extended east through Southeast Asia to Australia. In Australia, it inhabited waters from Shark Bay down to Jervis Bay. It prefers coastal areas with sandy or muddy bottoms. Mangroves and estuaries serve as key habitats. It can venture offshore to depths exceeding seventy metres. Rarely, it enters rivers far inland. It tolerates cooler water better than related sawfish.

How it lives

The animal feeds on fish, crustaceans, and molluscs. It swings its toothed snout side to side to stun prey. This action also digs food out of the seabed. While generally harmless, it can injure humans if caught and threatened. Large sharks and crocodiles may prey on it. Little is known about its full life cycle. Females give birth in shallow inshore areas. Young stay near the coast during early life. Sexual maturity occurs around nine years of age. One captive individual lived for thirty-five years.

Breeding and life cycle

Reproduction is ovoviviparous, meaning eggs hatch inside the mother. Newborns measure between sixty and one hundred and eight centimetres. Litter sizes are often cited as twelve, but this figure lacks clear evidence. Other sawfish species produce between one and twenty young. Females use inshore zones for birthing. Juveniles remain in estuaries and coastal waters for protection. They grow slowly, reaching maturity at roughly three and a half metres. Maximum lifespan is unknown but may exceed fifty years.

Fish and people

Fisheries target this species for its fins, meat, and saw. Fins are used in soup, while the rostrum serves as a novelty item. Parts are also used in traditional Asian medicine. Accidental capture in nets is a major threat. The toothed snout easily tangles in gillnets and trawls. Fishers sometimes kill them before bringing them aboard due to safety concerns. Small numbers exist in public aquariums. Studbooks recorded limited individuals in North America, Europe, and Japan in recent years.

Status and threats

The International Union for Conservation of Nature lists it as Critically Endangered. Populations have dropped by more than eighty percent over three generations. It has vanished from much of its historical range. Only eleven countries still support viable populations. Habitat loss, especially in mangroves, threatens remaining groups. Coastal development and oil extraction disrupt juvenile nurseries. International trade is restricted under CITES Appendix I. Protection laws exist in several nations, but enforcement remains weak.

Relatives and look-alikes

It is often confused with the dwarf, smalltooth, and largetooth sawfish. The knifetooth sawfish is another relative. Differences lie in tooth spacing, rostrum width, and fin placement. The longcomb has teeth closer together near the tip. Its rostrum is narrower than that of the dwarf or largetooth species. Unlike the smalltooth sawfish, which is Atlantic, this species is Indo-Pacific. Historical overlap with the smalltooth sawfish may have occurred in South Africa.

Questions people ask about Longcomb sawfish

Good reading and sources

• Longcomb sawfish on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data