Longcomb sawfish

The longcomb or green sawfish (Pristis zijsron) is a sizable species characterized by a robust, heavily-set body and a distinctive rostrum, adorned with 23-37 paired rostral teeth that are more closely spaced at the tip than at the base. The rostrum measures approximately 23-33% of the total body length. The first dorsal fin's origin is notably posterior to that of the pelvic fins, and the dorsal posterior margins are either straight or slightly concave. The pectoral fins are elongated and narrow, with anterior margins that are mildly convex and posterior margins that are straight. The caudal fin exhibits a weakly convex posterior margin in juveniles, which becomes straight in adults, and lacks a distinct lower caudal lobe and secondary lateral keel beneath the primary caudal keel at its base.

The dorsum of the green sawfish is typically greenish-brown or olive, while its ventrum and rostral teeth are white. This species predominantly inhabits coastal marine, mangrove, and estuarine environments, extending to depths exceeding 70 meters and exhibiting some presence far offshore. It can reach a maximum length of 7.3 meters, with newborns measuring approximately 80 centimeters.

Historically, the green sawfish was widespread across the 🌊 Indian Ocean and southwestern Pacific. However, it is now seldom encountered and potentially extinct in many areas of its former range. Remaining populations are found in the Gulf of Arabia, the 🌊 Red Sea, and throughout Southeast Asia and northern 🇦🇺 Australia.

The species reproduces via aplacental lecithotrophic viviparity, with litters averaging around 12 individuals. Its diet likely comprises crustaceans and other benthic invertebrates, while its largely sedentary nature has been observed through tagging studies in Northern 🇦🇺 Australia's Gulf of Carpentaria, where individuals traverse less than 200 meters in a 24-hour period.

Encounters with the green sawfish by divers or snorkelers are exceedingly rare, with the species generally elusive and difficult to approach, particularly due to poor visibility and the presence of saltwater crocodiles in Northern 🇦🇺 Australia.

Conservation Status: Critically Endangered

The green sawfish is listed as Critically Endangered due to its low rates of population increase and significant susceptibility to fishing pressures, particularly from gillnets and demersal trawl nets. The species has experienced drastic population declines across its range, exacerbated by historical commercial fishing activities. Though some protective measures have been implemented, such as no-take zones in several range states (including 🇦🇺 Australia, Bahrain, and 🇮🇳 India) and inclusion in CITES Appendix I, these efforts are insufficient to guarantee its survival globally. The population is suspected to have declined by over 80% in the past three generations (~44 years), with possible localized extinctions in certain regions. Despite a lack of precise quantitative data, available evidence suggests the species is now considerably rarer throughout its range, with 🇦🇺 Australia hosting some of the last viable populations.