Stingrays ( lat. Batomorphi [1] ) is one of two superorders [K 1] of plate- gill cartilaginous fish . Contains five units and fifteen families. Skates are characterized by a strongly flattened body and large pectoral fins, fused with the head. The mouth, nostrils and five pairs of gills are located on the flat and, as a rule, the bright underside. Tail shaped. Most stingrays live in sea water , but there are several freshwater species ( motor and others). The upper side of the slopes is adapted in color to a particular living space and can vary from light sand to black. On the upper side there are eyes and holes into which water for breathing penetrates - spatter (the first pair of gill slits).
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 Stingray Taeniura meyeni | |||||||||||||||||||||||||||
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Batomorphi | |||||||||||||||||||||||||||
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Stingrays live in all seas and oceans and live both in the cold waters of the Arctic and Antarctic and in the tropics, the temperature range of their habitats ranges from 1.5 to 30 ° C [3] . These fish are found both in shallow water and at a depth of up to 2700 m. Most species of stingrays lead a benthic lifestyle and feed on mollusks , crayfish and echinoderms . Pelagic species feed on plankton and small fish.
The dimensions of the slopes range from a few centimeters to 6-7 m in length. One of the most famous species of stingrays is manta ray ( Manta birostris ). The slopes of the brackish family reach large sizes, whose fins can reach 2.5 meters and a length of up to five meters; as well as stingrays from the family of stingrays, reaching 2.1 meters in width and up to 5.5 meters in length. A relatively large stingray-tail stingray cat is found in the Black and Azov Seas .
A special “weapon” is endowed with a detachment of electric stingrays , whose representatives, using a special organ from transformed muscles, can paralyze production with electric discharges from 60 to 230 volts and over 30 amperes [ specify ] .
Content
Anatomy and Physiology
Scales
In many species of skates, scales are reduced [4] . Placoid scales characteristic of stingrays among fish are the oldest in phylogenetic terms. Flakes are rhombic plates that end with a spike that protrudes from the skin to the outside. In structure and strength, the scales are close to the teeth , which gives reason to call it skin teeth. These teeth have a wide base, flattened shape and a very sharply defined crown. The spike of placoidal scales is even more durable, since the outside is covered with a special enamel - vitrodentin , formed by cells of the basal layer of the epidermis . Placoid flake has a cavity filled with loose connective tissue with blood vessels and nerve endings . In some species of stingrays, placoid scales are modified and look like large plaques on the body surface (for example, sea fox , Raja clavata ) or spines (for example, blue stingray , Pteroplatytrygon violacea ) [4] .
Nervous system
Three groups of sensory organs are well developed in stingrays (as well as other cartilaginous fish): organs of chemical reception (parallel to the sense of smell and taste of terrestrial animals), photoreception ( vision ), and organs of the acoustic-lateral system ( lateral line organ , Lorenzini ampoules ). In accordance with this, the brain of skates has three distinguished sections: the anterior one, which is responsible for chemical reception (olfactory bulb and olfactory lobe), the middle one, which is responsible for vision ( visual tubercles ) and the posterior part (including the medulla oblongata and cerebellum ), which processes signals, coming from the organs of the acoustic-lateral system. The degree of development of each part of the brain is associated with the ecological role of the corresponding sensory complex for this species.
It should be noted a high degree of autonomy of the spinal cord in skates, as in other aquatic cold-blooded animals [5] .
Electric organs
Skates, like other electric fish, have organs that produce electricity. Electric organs are paired symmetrical structures located laterally , consisting of electric plates assembled in columns. In stingrays, their weight reaches 25% of the mass of fish, in appearance they resemble a honeycomb . One organ consists of approximately 600 vertically placed hexagonal prisms. Each prism, which is a kind of battery, in turn consists of 40 or less electric disk-shaped plates separated by gelatinous connective tissue. In stingrays, electrical organs are located in the tail of the body. Sea slopes generate discharges of lower voltage, but high current strength (40-60 V at a current strength of 50-60 A) [6] .
Life Cycle
Reproduction
Stingrays are dioecious animals.
Stingrays breed either laying eggs enclosed in a capsule or laying them by egg-laying (the fry hatch from the egg at the time of laying). The fecundity of stingrays ranges from one to several dozen fry (in sawfish). From 4.5 to 15 months pass from laying to hatching eggs [7] . In electric stingrays and stingrays in the uterus, special villi, or trophotenia, additionally develop nutrients in the uterus.
Classification
The classification of the over-order of skates is currently undergoing revision, but molecular evidence disproves the hypothesis of the origin of rays in sharks [8] .
| Detachment | A photo | Title | Families | Childbirth | Species | Specifications | Sources | ||||
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| Torpediniformes | Electric ramps | 2 | 12 | 65 | 2 | 9 | Electric skates on pectoral fin discs have an organ that generates an electric current . With it, they immobilize the victim and defend themselves. The current strength is enough to stun a person, the ancient Greeks and Romans used these fish to treat diseases, for example, from a headache [9] | ||||
| Rajiformes | Stingrays or rhombotelic rays | one | ? | ? | four | 12 | 26 | Rajiformes include rhombic stingrays . They are distinguished by the presence of greatly enlarged pectoral fins, which protrude forward on both sides of the head, with a flattened body. They swim in wave-like movements with pectoral fins. The eyes and sprays are located on the dorsal surface of the body, and the gill slits on the ventral. They have flat teeth adapted for crushing prey; in general, these fish are carnivorous. Most species reproduce by live birth, although some lay eggs enclosed in a protective capsule. | |||
| Pristiformes | Sawfish | four | ? | ? | 3-5 | 2 |
Saw-like skates are similar to sharks, they swim with the help of a tail fin, their pectoral fins are smaller in comparison with other skates. The pectoral fins connect with the body above the gill fins, as with the other rays, which makes their head appear very wide. They have a long, elongated and flat snout with protruding lateral teeth. The length of the snout can reach 1.8 m, and the width is 30 cm. With its help, saw-like ramps beat and pierce small fish, and also dig in the mud in search of buried prey. Sawfish can swim in freshwater rivers and lakes. Some species reach 6 m in length. | ||||
| Myliobatiformes | Caudate | ten | 29th | 221 | one | sixteen | 33 | Myliobatiformes include stingray , stingrays , brackets and manti . Previously, they were included in the order Rajiformes , but phylogenetic studies have shown that they are a monophyletic group [11] . | |||
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| Stingray phylogenetic tree [12] |
The following modern families of stingrays are distinguished [13] :
- Squad Torpediniformes - Electric ramps , or gnusoobraznye
- Family Torpedinidae - Gnius
- Family Narcinidae - Daffodils
- Squad Rajiformes - Stingrays , or rhombotelic rays
- Rajidae Family - Rhombus Rays
- Order Pristiformes - Saw - like , or gnusoobraznye
- Family Rhinobatidae - Rukhly stingrays , or guitar
- Rhinidae Family
- Family Rhynchobatidae - Sharktail
- Pristidae Family - Sawlaws
- Order Myliobatiformes - Tailed
- Family Platyrhinidae - Platyrinous , or disk slopes
- Family Zanobatidae - Zanobatovye
- Family Plesiobatidae - Plesiobate
- Urolophidae family - Short - tailed Stingrays
- Hexatrygonidae Family - Six-ramps
- Dasyatididae Family - Stingray
- Potamotrygonidae Family - River Stingray
- Gymnuridae Family - Gymnastics
- Family Urotrygonidae - Stingrays
- Myliobatidae Family - Eagle rays
Differences between sharks and stingrays
| Comparison of sharks, stingrays and stingrays | |||
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| Characteristic | Sharks | Roe slopes | Ramps |
| The form | Spindle-shaped, laterally compressed | Dorsoventrally compressed disc (flattened) | Dorsoventrally compressed disc (flattened) |
| Splatter | Not available for all species | Available in all species. Developed better than sharks [3] . | |
| Habitat | usually feed in pelagic near the surface of the water, although there are bottom species | there are both pelagic and bottom species | usually feed near the bottom |
| Eyes | Usually located on the head laterally. The eyeball is not attached to the orbit. Blinking membrane is not available for all species. | Usually located on the head dorsally | Usually located on the head dorsally . The eyeball is attached to the orbit. No flashing membrane [3] |
| Gill slits | Located laterally | Located ventrally | |
| Teeth | As a rule, sharp and blade-like, but in some species they look like grater | Spike-shaped, strongly flattened and rounded [3] | |
| Pectoral fins | Visibly expressed | Not expressed | Not expressed |
| Tail | Large caudal fin, which serves to move forward | the tail fin can be used to move forward | the form varies from a thick tail, which is an extension of the body, to a thin “whip” coming to naught |
| Anal fin | Generally available, but not available in some species | Missing. | |
| Nature of movement | swim by moving the tail fin from side to side | in fly and pyloric skates, the caudal fin is like a shark | swim, flapping pectoral fins like wings |
Human Interaction
Usage
- In cooking
Stingray wings are a delicacy in Portuguese cuisine. In Korea, stingrays are eaten in the form of hwe (raw): a dish with them is called “honhohwe chomuhchim” ( cor. 홍어회 초무침 ), this is a “ regional specialization ” of the South Korean province of Chollado .
- In industry
The skin of stingrays is durable and has an unusual texture, it is used in the leather industry for the manufacture of wallets , belts , bags , briefcases , etc. The arms of Japanese katan swords are covered with the skin of stingrays.
- In research
- The maintenance of slopes in captivity
Danger to humans
Some types of stingrays are dangerous to humans. The force of the electric current generated by the electric ramps is enough to stun a person, and the stingrays are capable of causing painful wounds. In some cases, they can be life-threatening, - so a stingray-tail sting killed his famous naturalist, "crocodile hunter" Steve Irwin, with his poisonous sting.
Guard Status
All species of sawmill ramps are endangered or endangered.
Comments
- ↑ In some classifications, this group is assigned the systematic rank of “subdivision” (see Nelson, 2009, p. 129) or “department” (see Nelson, Grande, Wilson, 2016, p. 80)
Notes
- ↑ 1 2 3 4 5 6 Nelson J. S. , Grande T. C., Wilson M. V. H. Fishes of the World . - 5th ed. - Hoboken: John Wiley & Sons , 2016 .-- P. 80-82. - 752 p. - ISBN 978-1-118-34233-6 . - DOI : 10.1002 / 9781119174844 .
- ↑ Nelson D.S. Fishes of World Fauna / Transl. 4th rev. English ed. N. G. Bogutskaya, scientific. Ed. by A. M. Nasek, A. S. Gerd. - M .: Book House "LIBROCOM", 2009. - S. 129-132. - ISBN 978-5-397-00675-0 .
- ↑ 1 2 3 4 Animal life. Volume 4. Lancelet. Cyclostomes. Cartilaginous fish. Bone fish / ed. T. S. Rassa , ch. ed. V. E. Sokolov . - 2nd ed. - M .: Enlightenment, 1983. - S. 575. - 300,000 copies.
- ↑ 1 2 Ivanov, 2003 , p. 49.
- ↑ Ivanov, 2003 , p. 37.
- ↑ Ilmast N.V. Introduction to ichthyology. - Petrozavodsk: Karelian Scientific Center of the Russian Academy of Sciences, 2005. - P. 70–72. - ISBN 5-9274-0196-1 .
- ↑ Stingrays . bse.sci-lib.com. Date of treatment April 12, 2019.
- ↑ Douady CJ, Dosay M., Shivji MS, Stanhope MJ Molecular phylogenetic evidence refuting the hypothesis of Batoidea (rays and skates) as derived sharks (Eng.) // Molecular Phylogenetics and Evolution. - 2003. - Vol. 26 , no. 2 . - P. 215-216. - PMID 12565032 .
- ↑ Bullock, Theodore Holmes; Hopkins, Carl D .; Popper, Arthur N .; Fay, Richard R. Electroreception. - Springer, 2005. - S. 5-7. - ISBN 0-387-23192-7 .
- ↑ Faria VV, McDavitt MT, Charvet P., Wiley TR, Simpfendorfer CA and Naylor GJP Species delineation and global population structure of Critically Endangered sawfishes (Pristidae ) // Zoological Journal of the Linnean Society. - 2013 .-- Vol. 167 , no. 1 . - P. 136-164 . - DOI : 10.1111 / j.1096-3642.2012.00.0072.x .
- ↑ Nelson JS Fishes of the World. - 2006. - S. 69-82. - ISBN 0-471-25031-7 .
- ↑ Nelson, Grande, Wilson, 2016 , p. 81.
- ↑ Nelson, Grande, Wilson, 2016 , p. 81-93.
Literature
- A. A. Ivanov. Physiology of fish / Ed. S. N. Shestakh. - M .: Mir, 2003 .-- 284 p. - (Textbooks and teaching aids for students of higher educational institutions). - 5,000 copies. - ISBN 5-03-003564-8 .
- Nelson J. S. , Grande T. C., Wilson M. V. H. Division Batomorphi — rays // Fishes of the World . - 5th ed. - Hoboken: John Wiley & Sons , 2016 .-- P. 80-95. - 752 p. - ISBN 978-1-118-34233-6 . - DOI : 10.1002 / 9781119174844 .
- Gritsenko O.F., Kotlyar A.N., Kotenev B.N. Squat-like squad // Commercial fish of Russia. In two volumes. - M .: VNIRO, 2006. - T. 1. - 656 p. - ISBN 5-85382-229-2 , UDC 597.1 / .5 (470).