Atlantic pylori [1] [2] ( lat. Pristis perotteti ) is a species of fish of the family of sawmills of the family of sawn-like rays of the order of the saw-tail. These slopes live in the tropics and subtropics in the Indian and Pacific Ocean between 32 °. sh. and 19 ° S. sh. They are found in brackish and fresh waters at a depth of up to 122 m. The maximum recorded length is 650 cm. The long, flat outgrowth of the Atlantic sawn head is framed on the sides with teeth of the same size and resembles a saw. Externally, sawmills look more like sharks than slopes. They have an elongated body, there are 2 dorsal fins and a caudal fin with a developed upper lobe.
Atlantic sawmill |
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Scientific classification |
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No rank : | Bilateral symmetric |
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International Scientific Name |
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Pristis perotteti JP Müller & Henle , 1841 |
Security status |
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Endangered speciesIUCN 3.1 Endangered : 18176 |
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Like other pylori slopes, Atlantic pylori multiply by egg production . Embryos develop in the womb, feeding on the yolk . In litter up to 13 newborns. The diet consists of benthic invertebrates and small fish. The view is on the verge of extinction [3] [4] [5] .
The Atlantic sawmill was first scientifically described in 1841 [6] . The species is named after the French botanist Georges Samuel Perrotta , who provided a sample for study [7] .
Slopes belonging to the genus of pylori are conventionally divided into two groups with large and small teeth "saws". Sawmills with small teeth form a complex of species Pristis pectinata ( P. clavata , P. pectinata and P. zijsron ), and with large ones - a complex of Pristis pristis ( P. microdon , P. perotteti and P. pristis ), which needs further taxonomic studies . The International Union for Conservation of Nature has removed individual profiles of small-toothed and Atlantic sawmills, combining them with the profile of the European sawmill [5] .
Atlantic pylori live in the tropical and subtropical waters of the Atlantic and Eastern Pacific. Currently, they are no longer found in some previous habitats, for example, in the coastal waters of Florida [8] . Like other members of the sawmill family, they enter freshwater; there is evidence that this species has been found in the area of Santarem and Lake Nicaragua . These slopes stay in shallow water, as a rule, no deeper than 10 m, although there is evidence of their presence in Lake Nicaragua at a depth of 122 m [9] .
The maximum known size is 6.5 m, and the weight is 591 kg [4] . Externally, the Atlantic sawtooth is very similar to the comb sawtooth , with which they divide the range in the western Atlantic and some areas of the eastern Atlantic Ocean. The elongated flat rostrum of the Atlantic pylorus is littered with dent-like projections on both sides. The teeth are firmly and deeply fixed in hard cartilage tissue and do not grow back, being damaged [10] . A long, lamellar snout, gradually narrowing from the base to the end, has from 14 to 21 pairs of teeth on each side, in contrast to the comb sawn, in which the number of teeth ranges from 23 to 34 [8] . In Atlantic sawmills, large teeth comparable in size only to teeth of fine-toothed sawtooth [11] .
The body is long and slightly flattened. The mouth, nostrils and gill slits, like other rays, are located on the ventral surface of the body. There are small teeth in the mouth. Behind the small eyes are sprinklers that pump water through the gills and allow the stingrays to lie motionless on the bottom. There are 2 fairly large dorsal fins of approximately the same size, wide pectoral and triangular-shaped pelvic fins inferior to them, caudal fin with a developed upper lobe. Anal fin absent. The skin is covered with small placoid scales [10] . Scales lie less dense compared to the comb sawmills. In Atlantic pylori, the base of the first dorsal fin is located in front of the base of the ventral fins, whereas in the comb, it is at the same level vertically [8] . The dorsal surface of the body is dark gray or golden brown in color; individuals living in fresh water are mouse-gray with a reddish tinge of some parts of the body (back, sides, second dorsal fin and lateral sides of the caudal fin). The dorsal fin is pale yellow with a reddish tip. The reddish tint is due to a network of blood vessels that translucent through the skin. In the mouth there are 12 rows of functional dull teeth. The number of teeth increases with age: about 70 in newborns, and 80–90 in adult skates [8] .
Atlantic pylori are benthic fish feeding on crustaceans, molluscs, and small fish. With the help of a snout in search of food, they dig up the ground, injure their prey, and also defend against enemies, which in their natural environment are sharks, for example, narrow-toothed , blunt and tiger , and pointed crocodiles [8] . Their “saw” is littered with electro-receptors that help detect prey in turbid water [10] .
Like other pylori slopes, Atlantic pylori multiply by egg production. Fertilization is internal, embryos develop in the womb and feed on the yolk . These stingrays slowly grow and ripen, they have a small offspring. In litter 1-13 newborns (average 7-9). The rostrum teeth are covered with a soft shell so as not to injure the mother. In Lake Nicaragua, their length is approximately 76 cm. For saws belonging to this population, the mating season is from June to July, and the offspring are born from October to December. The breeding cycle is probably annual. Sexual maturity occurs with a length of about 300 cm. Life expectancy is estimated at 30 years [8] .
Monogenei Dermopristis paradoxus [12] , Erpocotyle caribbensis , Pristonchocotyle intermedia [13] , Nonacotyle pristis and Pristonchocotyle papuensis [14] , the cestodes Anthobothrium pristis , Phyllobothrium pristines , 14 Phylobothrium pritis , and Phyllobothrium prites , are parasitic on Atlantic pylori , and they are parasitic . , nematodes Terranova circularis and Terranova pristis [17] and copepods Caligus furcisetifer [18] and Ergasilus sp. [14] .
Pylorrhills have been commercially owned for a long time. The meat of these fish, especially the fins, which are an ingredient in the famous soup , is highly valued [19] . Liver fat is used in traditional medicine. The price for the rostrum can reach $ 1,000 or more [20] . A jagged rostrum makes them very vulnerable - they can become entangled in nets and debris floating in the water. The International Union for Conservation of Nature has removed a separate profile of the Atlantic sawmill, merging it with the profile of the European sawmill, which has the “On the Verge of Disappearance” conservation status due to environmental degradation and overfishing . Since 2007, trade in all types of sawflies, including their fins, meat, organs, skin, rostrum and rostral teeth, is prohibited [21] . Despite this, the poaching industry continues to threaten the livelihood of these fish.