The sawfish lives up to its name. Its elongated body and saw-shaped mouth make this fish highly feared. The scientific name is pristis pristis and, in the modern classification, it is integrated into the Pristidae family within the order Rhinopristiformes (batoids). In this article, we'll take a closer look at this fabulous fish to learn more about it.
You want to learn all the characteristics and way of life of the sawfish?
Key features
The sawfish family includes two genders (Anoxypristis and Pristis). Traditionally there were seven species, but Current taxonomic revisions recognize five living species. They are more related to the stripes than sharks and have a cartilaginous skeleton. The greatest attribute for which they are known is the flattened, saw-like snout (rostrum), flanked by rostral “teeth”.
The snout is covered by sensory and electroreceptor pores (ampullae of Lorenzini) that allow it to detect movements and electrical signals from buried animals. Its sensory capacity is so great that can perceive heartbeats of prey hidden under the sediment, which gives it a decisive advantage in benthic hunting.
Most of the activities are carried out thanks to the face in saw mode, which he uses for both attack and defense. It is a balanced tool with which he can catch, injure, and stun prey to devour them immediately, and also defend against predators like sharks and dolphins. The protruding elements of the snout are not true teeth, but modified dental scales (denticles). In the mouth, like other batoids, they do have small and numerous teeth suitable for your diet.
The muzzle is made up of 23 pairs of teeth in some individuals, and their number varies according to the species and size, generally being between 14 and 25 pairsIt is so big that represents more than a quarter of the total body and moves with precision to direct very fast side blows.
Sawfish can hunt in two ways. The first is to use their snout as a brush or rake, removing the sand where they hide. crustaceans, crabs and shrimpThe second consists of to hit from the side to banks de peces (such as lacerating or mullet), causing wounds that make them easier to catch. However, they are easy prey for sharks when they are young; as they grow, they are capable of defend themselves effectively.
Like other elasmobranchs, it lacks a swim bladder and controls buoyancy with a large, oil-rich liver. Their skin is covered with dermal denticles which give it a rough texture. It breathes through spiracles located behind the eyes that direct water towards the gills, a useful adaptation when resting on sandy bottoms.
Behavior
The sawfish is a nocturnal animal, quite passive, spending the day resting peacefully and being active at night and hunting. Despite its imposing appearance, does not attack people unless he feels threatened or gets caught and struggles with his saw.
It's an animal sedentary and demersal that spends most of its time on sandy or muddy bottoms. It usually lies close to the substrate, where it detects and digs up prey. Like other batoids, it can breathe using the large spiracles located behind the eyes while remaining motionless on the background.
He moves calmly, alternating short movements with periods of rest, and shows a activity marked by the tides in estuaries and bays, taking advantage of the flows to access feeding areas.
In juveniles, some degree of loyalty to specific areas breeding (natural nurseries in coastal or estuarine areas), which influences their conservation and the planning of protection measures.
Habitat and area of distribution
We can find the sawfish in areas tropical and subtropical. They are found in Australia, Africa, Ecuador, Portugal and areas of the CaribbeanTourists can observe them in shallow waters and in some aquarium exhibition agreements, where they occasionally appear in ocean tunnels.
It is able to live both in fresh and salt water. They are commonly located in river mouths, estuaries and bays, where the saline gradient does not cause them stress. Thanks to their temperament and physiology, they thrive in different aquatic environments, choosing places with abundant food and tranquility to rest during the day.
It has been found that some species travel great distances upriver and certain populations can inhabit rivers and lakes for long periods. In particular, juveniles of the largetooth sawfish (pristis pristis) they can remain in fresh water for several years before migrating to estuaries and coastal areas.
Because they spend most of their time on muddy and sandy bottoms, they take advantage of the opportunity to excavate and remove sediment with the saw, finding prey to feed on. The easiest prey are small and medium-sized tropical fish, invertebrates and molluscs, which lack effective defences against the rapid lateral blows of the rostrum.
Its historical distribution included large stretches of the western Atlantic (from areas near United States, such as Florida and Texas, to the Caribbean and northern South America) and other regions of the Indo-Pacific. Currently, populations have noticeably fragmented and survive in areas where suitable habitats and less fishing pressure persist.
Sawfish feeding
His diet is based on larger invertebrates, crustaceans and molluscs, along with benthic and demersal fish. To capture food, it combines the electrosensory detection of buried prey with the use of the rostrum as a rake and cutting weapon.
Even though they share a habitat, it is not common to see them feed on toxic or highly poisonous species; for example, they have not been documented eating a stone fish. In general, select prey that is easier to handle and with low risk.
When a sawfish is caught in artisanal fisheries, it does not usually present complications, although It is not widely consumed like other fish. Its flesh can be salted and eaten in some regions, although contains appreciable levels of mercury, so its frequent intake is not recommended. It often appears as bycatch in shrimp fishing and other trawling or gillnetting techniques.
Reproduction
Not everything is known about the reproduction of the sawfish, but it is known that they are ovoviviparous: the embryos develop inside the mother and she give birth to live young. During mating, males use claspers (copulatory organs located in the pelvic fins) to internally fertilize the female. This process can be vigorous and cause lacerations through the mountains between individuals.
Females reproduce once a year or every two years, with litters that, depending on the species and size of the mother, can vary between 1 and 23 pups (with documented maximums around that range). At birth, the young measure from 60 to 90 cm. While still in the womb, the saw remains soft or with a rubbery cover so as not to harm the mother; this covering is lost shortly after birth.
Sexual maturity is reached in a belated in most species of the genus Pristis (around 7–12 years, depending on the species), while in Anoxypristis may be earlier. To reach sexual maturity they must approach several meters in length. The low reproductive rate and slow development makes them very vulnerable to overfishing.
It has been observed parthenogenesis (asexual reproduction) in the smalltooth sawfish (pristis pectinata), where some offspring are clones of their mother when males are unavailable. This phenomenon is rare, but could represent a strategy of last resort in very decimated populations.
Taxonomy, species and differences with the saw shark
Sawfish belong to the class Chondrichthyesand whale shark, subclass elasmobranchii (sharks, rays and manta rays), superorder Bathoid and order Rhinopristiformes. The family is Pristidae and groups two genres: Pristis y AnoxypristisRecognized living species include pristis pristis, pristis pectinata, Pristis zijsron, Pristis clavata y Anoxypristis cuspidata. They have been described fossil species distributed globally, which shows a long evolutionary history of the group.
Not to be confused with sawfish (Pristidae) with the saw shark (order Pristiophoriformes). Although both have a “saw,” there are key differences: sawfish have gill slits on the ventral side (like stripes), they lack barbels in the mountains and his body is dorsoventrally flattened; saw sharks, on the other hand, have lateral gills and a couple of sensory barbels on the rostrum, with a silhouette more similar to that of a classic shark.
In sawfish, the mouth is in position ventral and has numerous small teeth for holding prey. The number of rostral teeth varies between species and sizes, and the coloration usually ranges from gray to brown or olive green on the back, with a whitish belly.
Conservation, threats and protection
The populations de peces mountain range have suffered declines greater than 90% in large areas of their distribution, and are an example among the endangered fish. All species of Pristidae are listed in the IUCN Red List as Critically EndangeredAmong its main threats are:
- Bycatch in gillnets and trawls: its sawfish tangles easily and makes release difficult.
- Targeted overfishing in the past due to the demand for its saw as a trophy and its use in traditional medicine.
- Habitat loss and degradation, especially of mangroves and estuaries that function as breeding areas.
There are international protection measures: the Pristidae family is included in CITES Appendix I, which prohibits or severely restricts international trade. Different countries have implemented closed seasons, catch bans and national action plans. In some regions, a day dedicated to the sawfish to raise awareness about its conservation.
In practice, conservation combines fisheries surveillance, protection of critical areas (nurseries in estuaries and mangroves), work with fishing communities to improve the safe release of hooked specimens and the use of scientific tools such as the Environmental DNA (eDNA) to detect the presence of populations. In public aquariums, some breeding and maintenance programs under human care contribute to the education and public awareness.
If you encounter this species, the general recommendation is avoid contact, do not attempt to manipulate it and, if it is damaged in fishing gear, apply release protocols that minimize injuries to the animal and people.
Relationship with humans: safety, consumption and sighting
Due to its morphology, the sawfish can be seen threatening, but it is an animal docile which rarely poses a direct danger. Accidents are associated with unwanted interactions, for example, during an accidental capture. Keeping your distance and avoiding stressing the animal is the best safety measure.
Regarding consumption, its meat is not highly appreciated and sawfish are not a priority fishing target. Occasionally they are processed salty, but its frequent intake is not recommended due to the potential metal content like mercury and due to its delicate conservation status. The priority is break free accidentally captured specimens.
For the general public, observe them in public aquariums or in its surroundings with responsible operators can be a way of enjoyment and environmental education, always under respectful practices with animals and current regulations.
Quick Facts and Curiosities
- Size: from 1,5 m to more than 6 m (the largest species reach exceptional sizes).
- rostrum: long and flattened, with pairs of “teeth” (denticles) that vary between 14 and 25 per side depending on species and size.
- Senses: highly developed electroreception to locate buried prey.
- Breathing: through spiracles that direct water to the gills while they rest on the bottom.
- Coloration: grey, brown or olive on the back; whitish belly.
- Behavior: nocturnal and demersal; not aggressive towards humans unless provoked.
- Reproduction: ovoviviparous; young born with soft ridges; internal fertilization; cases of parthenogenesis documented in P. pectinata.
With this information you will be able to learn more about the sawfish. Did you like it? Let us know in the comments :). Beyond its unique appearance, understanding its biology, habitat and threats It is key to ensuring its future: protecting estuaries and mangroves, reducing bycatch, and supporting science and education initiatives are decisive steps to ensure that the "saw" continues to silently plow through the planet's coastal seabed.
