Northern Sawfish

Facts about the Northern Sawfish, it is a sawfish that belongs to the genus Pristis of the Pristidae family. The scientific name of this fish is Pristis microdon and it is also called the Largetooth Sawfish, River Sawfish, Freshwater Sawfish, or Leichhardt's Sawfish. This fish is usually found in shallow waters of Indo-West Pacific oceans, but it can also be seen in the freshwater.

Features

The Northern Sawfish is a heavy-bodied sawfish that is capable of attaining a maximum body length of 23 feet (7 meters), when fully grown. The Northern Sawfish is seen with a short gigantic saw that is broad-based, powerfully tapering with 14 to 22 extremely big teeth on both sides, such that the gap between its last two sawteeth on its sides are less than two times the gap between the initial two teeth. The pectoral fins of the Northern Sawfish are elevated and angular, the primary dorsal fin being more often than not facing its pelvic fins, and its caudal fin has a distinct lower lobe.

As the Northern Sawfish is a sea or estuary species, it spends its initial three to four years in the freshwater. Sub-adults and juvenile fish mostly occur in estuaries and rivers, whereas big matured fish are inclined to occur more frequently in offshore and coastal waters up to a depth of 82.5 feet (25 meters). In the northern parts of Australia, the Northern Sawfish appears to be restricted to freshwater drainages and the higher reaches of estuaries, sometimes being found as remote as 400 km from the ocean. Some adult fish occur in fresh or weak salty water. The fish class inclines to move up streams during the time of floods and small fish, typically with the body length less than 5 feet (150 cm), have been caught in distant lagoons where they have been secluded for numerous years between floods.

The preferred home of the Northern Sawfish is sludge bottoms of estuaries and river embayments, but they can also be seen well upstream. However, they cannot be seen close to riparian vegetation, but they are generally found in muddy channels of large streams over soft sludge bottoms at a depth of 3.3 feet (1 meter). However, the Northern Sawfish species will move into shallow waters while hunting prey or while travelling upstream.

Northern Sawfish fish species with diverse age classes will partition home, with new occupants, remaining in the shallow waters for the majority part of the day when compared to the bigger ones that are more than one year old, will rarely move into the extreme shallow waters. Bigger fish will move to deeper water at sunrise and into shallower waters during the afternoon. Home stratification may be associated with foraging activities and, or predator prevention.

The Northern Sawfish species perform well in a bigger aquarium, filled with less alkaline water, with the temperature ranging from 22 degrees Centigrade to 28 degrees Centigrade.

Diet

The Northern Sawfish chiefly feeds on benthic invertebrates and fishes. The saw is exercised to shock schooling fish, like mullet, and for extracting small crustaceans and molluscs from the benthic residue.

The lifespan of the Northern Sawfish is considered to be 51 years.