Overview
The Green Sawfish (Pristis zijsron), celebrated as the Darget or Longcomb Sawfish, is a colossal, prehistoric ocean giant and the longest of all living sawfish species on Earth. Stretching up to an incredible twenty-three feet in total length, this magnificent creature looks like a living weapon from the dawn of time. Belonging to the batoid order Rhinopristiformes (flattened rays), it navigates tropical estuaries and coastal bays armed with an enormous, tooth-studded saw rostrum that functions simultaneously as a sensory antenna and an underwater scythe.
Biology and Physical Characteristics
Pristis zijsron possesses a robust, shark-like body structure with a flattened head and pectoral fins, olive-green to yellowish-brown dorsal coloration, and a pale white underside. Its defining evolutionary crown is its monumental rostrum (saw), which accounts for more than a quarter of the animal’s total length. This long, narrow blade is studded along both margins with 23 to 37 pairs of large, deeply embedded rostral teeth that grow continuously throughout its life. The rostrum is packed with thousands of electroreceptive Ampullae of Lorenzini that detect the minuscule electric fields generated by heartbeats of crabs and fish hidden beneath the sand. Its mouth and gill slits are located on its underside, typical of true rays.
Behavior and Ecology
Primarily nocturnal and benthic, the Green Sawfish cruises slowly over sandy and muddy substrates. When hunting, it uses its rostrum with astonishing speed and violent precision: sweeping its toothed blade sideways through schools of mullet and bream in rapid slashing arcs, impaling or stunning fish before pinning them to the seafloor to swallow whole. It also uses the saw as a biological rake to excavate buried shrimp and crabs from the sediment. Reproduction is aplacental viviparity: developing embryos inside the mother’s uterus grow soft, rubbery sheaths over their rostral teeth to protect the mother’s birth canal during delivery, which quickly harden upon exposure to seawater.
Conservation and Human Impact
The Green Sawfish is classified as Critically Endangered on the IUCN Red List and is listed on CITES Appendix I. Historically abundant from the Persian Gulf to the South China Sea, it has suffered a catastrophic global population collapse exceeding 80%, becoming functionally extinct across almost its entire Asian and African range. The primary driver of its collapse is its toothed rostrum, which becomes hopelessly entangled in commercial gillnets and prawn trawls. Today, the pristine, sparsely populated tropical coastlines of northern Australia (Queensland, Northern Territory, and Western Australia) represent the world’s last viable genetic stronghold for the species.
Interesting Factoid
The Green Sawfish is the longest sawfish on Earth at up to 23 feet long, and baby sawfish are born with soft, rubbery caps over their sharp saw teeth so they don’t accidentally cut their mother from the inside during birth!