Trachipterus trachypterus
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Trachipterus trachypterus |
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| Trachipterus trachypterus | ||||||||||||
| ( Gmelin , 1789) |
Trachipterus trachypterus (English: Mediterranean dealfish, Ribbon Fish) is a rare, worldwide occurring species of fish of the family of scythes ( Trachipteridae ) within the order of the glossy fish ( Lampriformes ). He is at home in all oceans of tropical and subtropical waters. It lives at depths of 100 to 600 meters, in some cases there are reports of up to 1000 meters depth.
morphology
Trachipterus trachypterus can reach a length of 300 cm. Its body shape is elongated in the shape of a band and flattened at the sides. Generally the appearance of T. trachypterus is elongated, laterally flattened and behind the short head lies the highest point of its silvery body. In addition to its silvery color, it has 3–4 dark spots along the side line and 1–2 spots on the ventral side. In addition, the front facet of the head is colored black at the level of the upper jaw and at the front end of the lower jaw. The fins are red-orange, often transparent, and connected by a membrane . A continuous dorsal fin reaching from head to tail consists of 145-185 dorsal fin rays. The anal fin is not present and the pectoral fins are only reduced. Large, round eyes are located near the top of the body in the adult animal. A jaw with small, backward protruding teeth is present in a forward small mouth. Although the species is scaly, it has bony tubercles . These become more and more visible on the lateral line organ in the direction of the caudal fin . The swim bladder is greatly reduced, if it is still there.
Compared to the adult animals, the young animals are shorter and the eyes are in the middle of the head instead of on the upper side of the body. The head is also steeper in the juveniles. The 5-6 rays of the dorsal fins and the 3–9 rays of the pelvic fins are longer with appendages at the end and give the appearance of jellyfish tentacles. When the fish reach a body length of 10 cm, the dorsal and pelvic rays shorten. The caudal fin becomes fan-shaped and has two parts: an upper one with longer rays directed upwards and a lower one with rays below the midline .
Trachipterus trachypterus is often confused with the northern sister species Trachipterus arcticus (Brünnich 1788). T. trachypterus has its highest point directly behind the head, whereas in T. arcticus it is further behind the head. Another distinguishing feature can be seen in the caudal fin, since the upper part is less present in T. arcticus . From further studies it is known that there are also differences in the number of vertebrae . T. trachyptus has 84-96 vertebrae, while T. arcticus has 99-102 vertebrae.
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distribution
These bony fish are found all over the world in the open water of the epi-mesopelagial zone, in tropical and sub-tropical waters. They have already been detected at depths of up to 1000 meters in some cases. Between 1962 and 1973 specimens were even caught at 1130–1355 meters during a measurement off Senegal .
However, juveniles can also be found near the coast, near the surface of the water and often in macro-plankton .
In the regions of the east Atlantic and the west coast of Africa as far as South Africa , on parts of the east and west coast of South America and the west coast of the USA, in the west and south Pacific as well as the Mediterranean area , the rare bony fish occurs. In the Mediterranean, however, it has been detected at depths of 100 - 600 meters and occurs there widespread in the Adriatic and Aegean Seas .
Although the fish are mainly brought to the surface as bycatch , there is no risk of extinction for T. trachypterus according to the International Union for Conservation of Nature ( IUCN ) .
Development and way of life
The main spawning season is from November to May, but can extend over the whole year. The eggs of T. trachypterus usually float near the surface in open water and are colored red. The morphology is characterized by a transformation from juvenile to adult fish.
Young animals are usually found near the surface of the water. These use their extended dorsal and ventral fins similar to a sail, so that they can passively carry themselves with the current and counteract the sinking movement. The animals swim upright in an upright posture while their dorsal fin moves in waves. Since the fish do not have a swim bladder and would otherwise sink continuously, this movement is very important.
Not much is known about a more precise swimming mode of T. trachypterus itself, but more precise observations have been made on the sister species T. arcticus . In the normal case, they take the typical vertical swimming style, without threat or stressful situations. If danger threatens, however, the fish are able to escape over short stretches in horizontal and eel-like movements. This movement takes place through the upper body flank and the wave-like movement of the dorsal fin. This is more pronounced in adult animals than in young animals.
nutrition
As a food source, especially demersal fish or small fish from the open water, serve squid , cuttlefish and squid . Among other things, an examination of the stomachs found plant parts, algae and plastic waste such as cigarette filters. These were presumably eaten through passive ingestion of the prey, but do not form a natural food source.
Systematics
The species was first described in 1789 as Cepola trachyptera by the German scientist Johann Friedrich Gmelin . The species Trachipterus trachypterus belongs to the genus Trachipterus , within the family of the scythes ( Trachipteridae ). Scythe fish belong to the order of the glossy fish ( Lampriformes ), within the ray fins ( Actinopterygii ), which forms a class of the bony fish ( Osteichthyes ).
Individual proof
- ↑ Borme, Diego .: On the occurrence of ribbon fish Trachipterus trachypterus (Gmeli, 1789) in the Gulf of Trieste (northern Adriatic Sea) . 2006, OCLC 450416505 .
- ↑ a b Trachipterus trachypterus summary page. Retrieved May 5, 2020 .
- ↑ a b c d e f g h Borme, Diego .: On the occurrence of ribbon fish Trachipterus trachypterus (Gmeli, 1789) in the Gulf of Trieste (northern Adriatic Sea) . 2006, OCLC 450416505 .
- ↑ a b c Marine Species Identification Portal: Deal fish - Trachipterus trachypterus. Retrieved May 5, 2020 .
- ^ A b Patrick Louisy: Europe and Mediterranean Marine Fish Identification Guide . Ulmer, 2015.
- ^ I. Farias, T. Moura, I. Figueiredo, AR Vieira, B. Serra-Pereira: Northernmost occurrence of the ribbonfish Trachipterus trachypterus (Gmelin, 1789) in the NE Atlantic: the Portuguese continental shelf . In: Journal of Applied Ichthyology . tape 26 , no. 1 , 2010, ISSN 1439-0426 , p. 143-144 , doi : 10.1111 / j.1439-0426.2009.01294.x .
- ↑ Dr Tony Ayling: Trachipterus trachypterus (Ribbon fish). 1982, accessed May 5, 2020 .
- ↑ Гурьева Светлана: Русский: Trachipterus trachypterus, экспонат в музее. June 11, 2015, accessed May 5, 2020 .
- ^ A b c d William F. Smith-Vaniz (??): IUCN Red List of Threatened Species: Mediterranean Dealfish. May 7, 2013, accessed May 5, 2020 .
- ↑ Quéro, JC: Poissons des côtes nord-ouest africaines (campagnes de la "Thalassa" 1962, 1968, 1971 et 1973) saccopharyngiformes, anguilliformes, beryciformes, zeiformes, lampridiformes et gasterosteiformes . Institut scientifique et technique des pêches maritimes, 1982, OCLC 853049980 .
- ↑ a b IUCN Red List of Threatened Species: Mediterranean Dealfish. November 16, 2007, accessed May 5, 2020 .
- Jump up ↑ Moritz, T., Stümer, D., Jakobsen, K., & Jakobsen, J .: Observations on two live specimens of Trachipterus arcticus (Lampriformes: Trachipteridae) from the Azores. 2015, p. 78-80 .
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