Bleher's redhead tetra

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Bleher's redhead tetra
Brilliant rummy nose.jpg

Bleher's red head tetra ( Petitella bleheri )

Systematics
Sub-cohort : Ostariophysi
Otophysa
Order : Tetras (Characiformes)
Family : True tetras (Characidae)
Genre : Petitella
Type : Bleher's redhead tetra
Scientific name
Petitella bleheri
( Géry & Mahnert, 1986)

Bleher's Rotkopftalmler ( Petitella bleheri ; synonym : Hemigrammus bleheri ) is a fish from the family of the real tetra . Its original home is in northwestern Brazil and in southern Colombia on the Amazon . The German name "Rotkopfsalmler" was coined in 1967 by the wholesaler Otto Schulze.

Natural habitat

Petitella bleheri
Petitella rhodostomus

The extremely lively and peaceful schooling fish feels particularly at home in textured and darker surroundings. Preferred environments are habitats in which vegetation does not prevail, but some denser plant hiding places are available. The ichthyologist Rüdiger Riehl (1949–2012) stated in 2004 that Bleher's red-headed tetra is to be regarded as a blackwater fish. Ulrich Schliewen , ichthyologist and section head of the Zoological State Collection in Munich , on the other hand, identified clear and black water streams as the original home waters in 2011 , while the biologist Jürgen Schmidt had already written in 2001 that Bleher's red-headed tetra inhabits all types of water, preferably small side streams and oxbow lakes. Thus white water brooks can also belong to his refuge. This finding also shows how wide the range of habitats of the Hemigrammus bleheri can be. Most of the Amazonian waters are black water biotopes and are formed by rainwater. They have pH values in the acidic to extremely acidic range and are very poor in dissolved minerals. This means that their electrical conductivity and the overall and carbonate hardness are extremely low. Since the lack of minerals in black water is often only slightly removed from the salt content of distilled water , the chemistry of the two types of water hardly differs.

The Rio Negro , especially the middle Rio Negro in Brazil , is often given as the type locality of the species . It can also be found on its right tributary , the Río Vaupés , which comes from Colombia and flows into the Rio Negro on Brazilian territory. In addition, the red-headed tetra lives in parts of the catchment areas of the upper Colombian Orinoco and the Río Meta, which flows into the Orinoco . The biologist Wolfgang Staeck also observed the fish in the catchment of the lower Rio Inirida , which also drains into the Orinoco via the Río Guaviare .

Real aquatic plants are not found very often in black water, since the light usually cannot penetrate far into the water. Due to the precipitation, however, the water is enriched with organic substances from the jungle soils, which have high humic and tannin contents. Many tetra species therefore tend to live in areas where clear and black water mix. These mixed waters are not uncommon in the tropics. The clear water biotopes of Amazonia, which are often strongly acidified, are also poor in nutrients, similar to the black water. Their water, which has no turbidity and hardly any organic components, comes from areas in which it was unable to absorb any or only very few minerals from the soil or rock. The few dissolved minerals mean that this type of water is also very reminiscent of distilled water. Typical pH values ​​are in the range from 4.4 to 6.6, with the extremely low nitrogen content showing the high purity of the water. The Amazon itself is a white water river with a very low hardness, the pH of which fluctuates between 6.5 and 6.9 and sometimes also reaches the neutral value of 7. The total and carbonate hardness of the river often reaches values ​​of 1–2 ° dGH. Sunlight penetrates the sediment-rich, cloudy water only a few centimeters deep, so that real aquatic plants are missing. Swamp and floating plants take their place. The white water comes from geologically young areas and carry a variety of dissolved substances.

features

Bleher's red-headed tetra has a characteristic, signal-colored drawing with a blood-red head and a black-and-white banded tail. The iris is also red in color. It is believed that this pattern serves to communicate changes in direction of the swarm in the murky water. It shares these colors with Petitella rhodostomus from the Lower Amazon and the slightly larger Georgies red-headed tetra ( Petitella georgiae ), which is also known under the name "Peru-red-headed tetra" and lives mainly in the Peruvian Upper Amazon region. Bleher's red head tetra is slim and at least up to 4.5 centimeters long, with the females being plump. Schmidt (2001) gave the final size of the fish five centimeters and Schliewen (2017) even 5.5 centimeters.

Bleher's red head tetra looks very similar to Petitella rhodostomus (Ahl's red mouth tetra ) and Petitella georgiae (Georgie's red head tetra ). However, the red mouth tetra has a dark longitudinal ligament on the body. In Bleher's red-headed tetra, the red markings extend beyond the gill cover.

Behaviors

Like the species of the genus Hemigrammus, it spawns freely in pairs between slender aquatic plants, whereby Bleher's redhead tetra also likes to appear as spawning predators. However, the spawning mother is ready to defend her brood. It chases away other fish that approach the spawn. The fry hatch after 30 to 36 hours and are free swimming after the fourth day. The importance of constant fresh water for spawning becomes clear when it is taken into account that the fish in its native environment apparently settles the spawn in flowing waters. In contrast to the artificial parameters that prevail in aquariums and the possible range of temperatures and pH values ​​in natural habitats, there are also some important values ​​that may only be exposed to minor fluctuations. This applies in particular to the content of hardness-forming salts and the contamination caused by humans. This makes it clear that Bleher's redhead tetra is not very adaptable when it comes to the hardness and cleanliness of the water. The Swiss breeder Hugo Benninger had very good experiences with the reproductive behavior and the development of spawn and larvae with strongly flowing, unpolluted and very clean water with the lowest possible conductivity (20 μS / cm). As with most tetra, the behavior and habits of the red-nosed fish cannot be compared with those of real schooling fish, such as herring .

Systematics and taxonomy

The species first described by the French ichtyologist Jacques Géry (1917-2007) and the Austrian entomologist Volker Mahnert (1943-2018) in 1986 was named after the German ichthyologist Heiko Bleher , who discovered the fish in 1965. For a long time Bleher Rummy with the 1924 by the German ichthyologists Ernst Ahl (1898-1945) first described rummy-nose tetra equated and visual differences as natural variety seen before realized through further research that Rotnasen particular by differences in color and skull morphology as independent type are to be seen. Even today, the original equation of the species still leads to confusion, especially if parts of the older literature are used.

In a phylogenetic investigation of the internal systematics of the Characidae, the research in connection with a revision of the genus Astyanax and a study published in mid-2020 on the closer relationship of the neon fish ( Paracheirodon ), it was found that Bleher's red- headed tetra is closely related to Georgie's red-headed tetra ( Petitella georgiae ) and represents its sister species. Bleher's Rotkopfsalmler and Ahls Rotmaulsalmler, originally belonging to Hemigrammus , were then placed in the genus Petitella .

Aquaristics

Keeping and care

Preliminary information

The German Animal Welfare Act (TierSchG) requires that all animals to be cared for must be fed, cared for and housed appropriately according to their species and needs. No one should inflict pain, suffering, or harm on an animal for no good reason. In addition, keepers must have the knowledge and skills required for adequate nutrition, care and behavioral accommodation of the animal. In a similar way, the Animal Welfare Act in Austria stipulates that no animal may be inflicted unjustifiably pain, suffering or harm, or that it may be terrified. There animals are to be kept in such a way that their bodily functions and behavior are not disturbed and their adaptability is not overwhelmed. In Switzerland, in addition to similar aspects, the dignity, the intrinsic worth of an animal, comes into play. Animals are not toys and therefore do not belong in the hands of children.

Before buying an aquarium, sufficient information on keeping it must be available. Mere brief information from the retailer or often contradicting information from the Internet is not enough, so specialist literature should be acquired for each type before buying. For a large part of the aquatic animals kept by humans, the smaller an aquarium is planned, the more complicated it is to keep them, since a stable balance of the complex biological-ecological structures and functions of the abiotic and biotic processes is more difficult to achieve. In community aquariums in particular, it quickly becomes clear how fragile and unstable an otherwise intact habitat can become in the event of human failure. Here beginners' mistakes can be avoided with appropriately acquired information.

Dealing with the fish

Bleher's red-headed tetra, which is now on the market as offspring and has a sturdier stature than wild-caught fish, is a very active fish and, like almost all tetra, needs to be cared for in larger groups in order to feel really good. Nevertheless, the red noses only form groups when they feel insecure or threatened. This almost always happens when people come too close to the aquarium or when work has to be done in the tank. Otherwise, the animals like to separate and swim their own way. Under no circumstances should a tank with red-headed tetras be in a hectic environment, because the fish need a somewhat more secluded environment with a lot of peace for a long, healthy life in order to feel safe and comfortable. Therefore, the aquarium must be set up in such a way that it is safe from other pets such as cats, but also from small children. Nor should it be in places where there is constant back and forth. In addition to sufficient free space for swimming, species-appropriate hiding places in the pool are absolutely necessary, as red-headed tetra, even as young animals, are very jumpy and, for example, there is always the risk of animals jumping out of the aquarium when the water is changed too hectically or when cleaning the aquarium. If red-headed tetra feel uncomfortable, have just been relocated or have only just awakened, the red color of the animals is usually very pale. If the animals do not recover and if the pale color is retained, something is wrong. As is clear from the descriptions of its natural environment, Bleher's redhead tetra receives constant fresh water in nature. This fact can be simulated by regular water changes. Since Petitella bleheri can live up to eight years, keepers should prepare accordingly.

Aquarium

Schliewen stated that the minimum size for a species aquarium in 2011 was 80 × 35 × 40 centimeters. In doing so, he had corrected his minimum information from 1998 upwards, since at that time he still considered a 60 centimeter long pool to be sufficient. In 2001, Schmidt also needed an aquarium with a side length of 80 centimeters or more. According to Schmidt, the basin should at least be able to hold 100 liters of water. In 2011 Schliewen considered a minimum number of ten animals to be necessary. The aquarium facility should be loosely planted and dark, with a slight current being part of the natural habitat. Floating plants can help to reduce the incidence of light. Roots also enhance the fish's habitat. The colors of the animal are emphasized with a dark substrate. A community pool should have a size of 100 centimeters or more.

Water values

For the keeping of the red noses, experts sometimes recommend quite different values. According to Schmidt (2001), the German total hardness should be 2–16 ° dGH. The pH value is set at 5.0–7.0 by Schmidt (2001), 6.0–6.5 by Riehl (2004) and 6.0–7 by the authors Oliver Knott and Chris Lukhaup (2013) , 0 specified. Riehl defines the carbonate hardness as "harder than 4 ° KH". According to Schmidt (2001) and Schliewen (2017), the necessary water temperature is 22–26 ° C. The zoologist Heinz Mehlhorn and the biologist Günter Schmahl (both 1992) named 23–26 ° C, Knott and Lukhaup (2013) said it was 25–27 ° C; specified. Riehl, however, was of the opinion that a temperature of 25–28 ° C was appropriate. In 2001 Benninger assumed that there are also temperature and pH fluctuations in the fish's natural habitats. This explains the good adaptability of these animals. Since excessive nitrate values ​​are harmful to Bleher's redhead tetra, regular water changes should be ensured.

feeding

Feeding can take place with all common small types of food. Bleher's red-headed tetra gladly accepts dry food , but frozen food should always be given as a high-quality nutritional supplement for successful keeping , whereby mosquito larvae are very welcome and have an optimal nutritional value. Also live food is welcome to be given is at the Rotnasen but not a must. Overfeeding must be avoided, as otherwise not only could the vital water values ​​drop, but the fish also suffer, as they have no natural brake on food intake and there is a risk that the animals will overeat. Aquarium fish can become overweight and lose their health.

Socialization

Bleher's red head tetra is easy to socialize with other tetras. The specialist book author Bernd Degen can also imagine discus fish as partners for the red noses. In addition to the discus fish, Schliewen also regards dwarf cichlids as ideal community fish , whereby for the latter two species the aquarium must have a minimum size of 100 centimeters. Armored catfish and ear lattice armor catfish are possible as further partners in the community pool.

Offspring

According to Schmidt (2001), offspring is already successful in a small species aquarium from 40 centimeters for a pair. As equipment, it is a spawning grate as well as some Java moss on. Due to the already mentioned frightfulness and the possible danger of jumping out of the rearing containers of young animals, make sure that the water level is at least two to three centimeters below the upper edge of the aquarium. The young have to be fed the smallest type of freshwater plankton as they are really very small. As already mentioned, they should not come together with the adult animals as they like to be eaten. Benninger stated that the breeding temperature was between 26 and 30 ° C, saw a variable pH value between 5.5 and at least 7 as possible and recommended the use of an ion exchanger or a reverse osmosis system . Bleher's red head tetra is a "night spawner" that spawns before dawn. The spawn is not sensitive to light, but it should still be darkened as the lavas avoid the light.

Legal regulation in Austria

In Austria, the minimum requirements for keeping fish are defined in Regulation 486 in Section 7 and its Annex 5. See also the Wikipedia entry ornamental fish . The following also applies specifically to red-headed tetra: At least 5 animals of this species must be kept and the following limit values ​​must be observed:

value annotation
Minimum size of the aquarium 80 × 35 × 40 Length × width × height in [cm]
Area for the water temperature 22-29 Degrees Celsius [° C]
Area for the water hardness 0-15 Degree of German total hardness [⁰dGH]
PH range 5.0 - 8.0 Acidity
Maximum value of nitrate 50 [mg / l]

Web links

Commons : Blehers Rotkopfsalmler ( Hemigrammus bleheri )  - Collection of images, videos and audio files

literature

  • Jacques Géry , Volker Mahnert : A new rummy-nose tetra from the Rio Negro, Brazil: Hemigrammus bleheri n. Sp. (Characidae, Tetragonopterinae), with comments on Paracheirodon . In: Tropical Fish Hobbyist 34, No. 11 (1986), pp. 37-52.
  • Jürgen Schmidt : Tetrao. The fascination of aquarium fish farming. Bede, Ruhmannsfelden 1998, ISBN 3-931-792-41-2 .
  • Jürgen Schmidt: Salmler (= your hobby ) Bede, Ruhmannsfelden 2001, ISBN 3-931-792-74-9 , p. 66.
  • Heiko Bleher : The story of the real redhead tetra "Hemigrammus bleheri" . In: Aquarium heute 7, No. 1 (1989), pp. 49-51.
  • Heiko Bleher: The Most Spectactular Rummy-nose - An odyssey in search of the fiery Hemigrammus bleheri . In: Tropical Fish Hobbyist (April). TFH Publication, New Jersey 1987. pp. 10-21.
  • Rüdiger Riehl : Aquarien Atlas 3. Mergus, Melle 1997, ISBN 3-88244-114-3 .
  • Hugo Benninger: Is it difficult to breed the redhead tetra? In: The aquarium and terrarium magazine 54 No. 5 (2001), pp. 16-18.
  • Ulrich Schliewen : Aquarium fish from A to Z. Portrait of over 300 popular freshwater fish . Gräfe and Unzer, Munich 2017, ISBN 978-3-8338-5578-8 .
  • Wolfgang Staeck : Tetra from South America. Habitats and care in the aquarium. Daehne, Ettlingen 2008, ISBN 978-3-935175-41-8 .
  • Wolfgang Staeck: Observed in nature: red head tetra. In: The Aquarium and Terrarium Magazine 72, No. 10 (2019), pp. 28–31.

supporting documents

  1. ↑ a b Petitella bleheri in the Catalog of Fishes (English)
  2. ↑ a b c d e Birgit Mehlhorn, Heinz Mehlhorn , Günter Schmahl : Health for ornamental fish. Recognize and fight parasites . Springer, Berlin / Heidelberg 1992, ISBN 978-3-540-55535-3 , p. 150.
  3. ↑ a b c d Ulrich Schliewen : Practical Guide Aquarium. With over 400 species of fish, amphibians and invertebrates in portrait . Gräfe and Unzer, Munich 2017, ISBN 9783833861390 , p. 181.
  4. ↑ Heiko Bleher : The Most Spectactular Rummy-nose - An odyssey in search of the fiery Hemigrammus bleheri . In: Tropical Fish Hobbyist (April). TFH Publication, New Jersey 1987. pp. 10-21.
  5. ↑ a b c d e Oliver Knott , Chris Lukhaup : Aquascaping. Design aquarium landscapes. Gräfe and Unzer, Munich 2013, ISBN 978-3-8338-2411-1 , p. 251.
  6. ↑ a b c d e f g h i Rüdiger Riehl : Aquarien Atlas 3, Mergus, Melle 2004, ISBN 3-88244-053-8 ; P. 130.
  7. ↑ a b c d e f g h i j Jürgen Schmidt : Salmler (= your hobby ) Bede, Ruhmannsfelden 2001, ISBN 3-931-792-74-9 , p. 66.
  8. ^ A b Wolfgang Staeck : Tetra from South America. Habitats and care in the aquarium. Daehne, Ettlingen 2008, ISBN 978-3-935175-41-8 . P. 30.
  9. ↑ a b c d e Jürgen Schmidt : Salmler. The fascination of aquarium fish farming. Bede, Ruhmannsfelden 1998, ISBN 3-931-792-41-2 . P. 10.
  10. ↑ Wolfgang Staeck: Observed in nature: Rotkopfsalmler. In: The Aquarium and Terrarium Magazine 72, No. 10 (2019), pp. 28–31.
  11. ↑ Wolfgang Staeck: Observed in nature: Rotkopfsalmler. In: The Aquarium and Terrarium Magazine 72, No. 10 (2019), pp. 28–31.
  12. ^ A b Wolfgang Staeck : Tetra from South America. Habitats and care in the aquarium. Daehne, Ettlingen 2008, ISBN 978-3-935175-41-8 . P. 31.
  13. ^ Wolfgang Staeck : Tetra from South America. Habitats and care in the aquarium. Daehne, Ettlingen 2008, ISBN 978-3-935175-41-8 . P. 33.
  14. ↑ Joachim Stengert: Care and breeding of the Peru red head tetra . In: The aquarium and terrarium magazine 5, 1990, p. 281 ff .; here: p. 281.
  15. ^ Günther Sterba : Freshwater fish of the world . Ulmer, Stuttgart 1987, ISBN 3‐8001‐7165‐1, p. 119.
  16. ↑ a b c d e f Ulrich Schliewen: Aquarium fish from A to Z. Over 300 popular freshwater fish. With beautiful small fish for the nano . (= The Great Compass ) Gräfe and Unzer, Munich 2011, ISBN 978-3-8338-2191-2 , p. 42.
  17. ↑ a b c d Hugo Benninger: Is it difficult to breed the red head tetra? . In: The aquarium and terrarium magazine 54 No. 5 (2001), pp. 16-18; here: p. 16.
  18. ↑ Jacques Géry , Volker Mahnert : A new rummy-nose tetra from the Rio Negro, Brazil: Hemigrammus bleheri n. Sp. (Characidae, Tetragonopterinae), with comments on Paracheirodon . In: Tropical Fish Hobbyist 34, No. 11 (1986), pp. 37-52.
  19. ↑ Juan Marcos Mirande (2018): Morphology, molecules and the phylogeny of Characidae (Teleostei, Characiformes). Cladistics, June 2018. doi: 10.1111 / cla.12345
  20. ↑ Terán, GE, Benitez, MF & Mirande, JM (2020): Opening the Trojan horse: phylogeny of Astyanax , two new genera and resurrection of Psalidodon (Teleostei: Characidae). Zoological Journal of the Linnean Society: zlaa019. April 2020. doi: 10.1093 / zoolinnean / zlaa019
  21. ↑ Bittencourt, PS, Machado, VN, Marshall, BG, Hrbek, T. & Farias, IP (2020): Phylogenetic relationships of the neon tetras Paracheirodon spp. (Characiformes: Characidae: Stethaprioninae), including comments on Petitella georgiae and Hemigrammus bleheri. Neotropical Ichthyology, 18 (2): [1-11]. doi: 10.1590 / 1982-0224-2019-0109
  22. ↑ Petitella rhodostomus in the Catalog of Fishes (English)
  23. ^ Federal Ministry of Justice and Consumer Protection / Federal Office of Justice: Animal Protection Act.
  24. ↑ Federal Act on the Protection of Animals (Animal Protection Act - TSchG)
  25. ^ Animal Welfare Act of December 16, 2005 (TSchG)
  26. ↑ a b Joachim Stengert: Care and breeding of the Peru red head tetra . In: The aquarium and terrarium magazine 5, 1990, p. 281 ff .; here: p. 282.
  27. ↑ a b c [1] ; Harro Hieronimus : Portrait of the red head tetra at www.zooroyal.de
  28. ^ Ulrich Schliewen: How to Care for Them, Feed Them, and Understand Them (= Family Pet Series ) Barron's Educational Series, 1998, ISBN 0-7641-5084-7 , p. 16.
  29. ^ Ulrich Schliewen : Aquarium fish from A to Z. Portrait of over 300 popular freshwater fish . Gräfe and Unzer, Munich 2017, ISBN 978-3-8338-5578-8 , p. 42.
  30. ↑ Jörg Vierke : Small aquariums. Extra: nano aquariums . Kosmos, Stuttgart 2010, ISBN 978-3-440-12126-9 , p. 44.
  31. ^ Ulrich Schliewen: How to Care for Them, Feed Them, and Understand Them (= Family Pet Series ) Barron's Educational Series, 1998, ISBN 0-7641-5084-7 , p. 91.
  32. ↑ Bernd Degen: The great discus book . Bede, Ruhmannsfelden 2008, ISBN 978-3-89860-159-7 , p. 283.
  33. ↑ Hugo Benninger: Is it difficult to breed the red head tetra? . In: The aquarium and terrarium magazine 54 No. 5 (2001), pp. 16-18; here: p. 18.
  34. ↑ BGBl II No. 486, 2nd Animal Husbandry Ordinance. Retrieved January 24, 2019 .
  35. ↑ a b BGBL II No. 486 Annex 5, minimum requirements for keeping fish. Retrieved January 24, 2019 .