Largetooth Sawfish

The largetooth sawfish may mature to 15 ft in total length, though the largest confirmed specimen was a 7 m (23 ft)-long West African individual. A sawfish caught in 1951 near Galveston, Texas, was documented on film but not measured; this fish has been estimated to be of similar size. Today, most individuals are far smaller and a typical length is 2–2.5 m (6.6–8.2 ft). Large individuals may weigh as much as 500–600 kg (1,102–1,323 lb), or possibly even more. The largetooth sawfish is recognized by the forward position of the dorsal fin with its leading edge placed in front of the leading edge of the pelvic fins (when the sawfish is seen from above or the side), the relatively long pectoral fins with angular tips, and the presence of a small lower tail lobe. In all other sawfish species the leading edge of their dorsal fin is placed at, or behind, the leading edge of the pelvic fins, and all other Pristis sawfish species have shorter pectoral fins with less pointed tips and lack a distinct lower tail lobe (very small or none). The rostrum ("saw") of the largetooth sawfish has a width that is 15–25% of its length, which is relatively wide compared to the other sawfish species, and there are 14–24 equally separated teeth on each side of it. On average, females have shorter rostrums with fewer teeth than males. The rostral teeth are large and grooved from base to tip. …

The largetooth sawfish can be found worldwide in tropical and subtropical coastal regions, but it also enters freshwater and has been recorded in rivers as far as 1,340 km (830 mi) from the sea. Historically, its East Atlantic range was from Mauritania to Angola. There are old reports (last in the late 1950s or shortly after) from the Mediterranean and these have typically been regarded as vagrants, but a review of records strongly suggests that this sea had a breeding population. Its West Atlantic range was from Uruguay to the Caribbean and the Gulf of Mexico. Although there are claimed reports from several Gulf Coast states in the United States, a review indicates that only those from Texas are genuine. Other specimens, notably several claimed to be from Florida, were likely imported from other countries. Its East Pacific range was from Peru to Mazatlán in Mexico. Historically it was widespread in the Indo-Pacific, ranging from South Africa to the Horn of Africa, India, Southeast Asia and Northern Australia. Its total distribution covered almost 7,200,000 km2 (2,800,000 mi2), more than any other species of sawfish, but it has disappeared from much of its historical range. The last record taken in the Mediterranean dates back to 1959. …

The largetooth sawfish's maturity is reached once a length of about 2.8–3 m (9.2–9.8 ft) is attained, at roughly 7–10 years old. Breeding is seasonal in this ovoviviparous species, but the exact timing appears to vary depending on the region. The adult females can breed once every 1–2 years, the gestation period is about five months, and there are indications that mothers return to the region where they were born to give birth to their own young. There are 1–13 (average c. 7) young in each litter, which are 72–90 cm (28–35 in) long at birth. They are likely typically born in salt or brackish water near river mouths, but move into freshwater where the young spend the first 3–5 years of their life, sometimes as much as 400 km (250 mi) upriver. In the Amazon basin the largetooth sawfish has been reported even further upstream, and this mostly involves young individuals that are up to 2 m (6.6 ft) long. Occasionally, young individuals become isolated in freshwater pools during floods and may live there for years. The potential lifespan of the largetooth sawfish is unknown, but four estimates suggested 30 years, 35 years, 44 years, and 80 years. The largetooth sawfish is a predator that feeds on fish, molluscs and crustaceans. The "saw" can be used both to stir up the bottom to find prey and to slash at groups of fish. …