Honey gourami
| Honey gourami | ||||||||||||
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Honey gourami ( Trichogaster chuna ) ♂ |
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| Trichogaster chuna | ||||||||||||
| ( Hamilton , 1822) |
The honey gourami or honey thread fish ( Trichogaster chuna ) is a freshwater fish from South Asia belonging to the labyrinth fish. It is the smallest representative of the " Western thread fish ".
distribution
The distribution area is in the northeastern part of the Indian subcontinent in the lower reaches and deltas of Brahmaputra and Ganges . Honey threadfish have been identified in the Indian states of Uttar Pradesh , Bihar , Jharkhand , West Bengal and Assam as well as in Bangladesh .
features
Gouramfish are the smallest gourami with a total length of about five centimeters. Within the genus Trichogaster (until recently they were classified in the genus Colisa , but newer assignments led to the renaming; the previous Trichogasters are now in Trichopodus ) they take due to their fin formula (more hard rays in the dorsal and anal fin), the missing vertical Body drawing and the coloring of the larvae have a special position. Outside the breeding season, both sexes have an ocher-brown basic color on which there is a brown longitudinal band that runs from the upper lip to the base of the caudal fin and is more or less pronounced depending on the mood. In the splendid coloring of territory-forming or brood-tending males, the hard-radiating part and the upper edge of the dorsal fin are lemon yellow, the head, throat and chest area up to the first third of the anal fin are blue-black to black and the body is brown-red to orange-red. Females grow slightly larger than males.
Fins formula : dorsal XVII – XIX / 6–9, anal XVII – XXII / 11–15.
ecology
Few reports of field observations indicate shallow bank and floodplain areas with dense vegetation as habitat . Krause names the months of August to October as the breeding season. The water temperatures at this time are between 26 and 30 ° C. Outside of the breeding seasons and in open water, honey threadfish form swarm-like associations. A large proportion of their food consists of flying insects, which they ingest from the surface of the water or shoot from locations above the water with targeted spitting movements.
Reproduction
In contrast to all other thread fish of the genus Trichogaster , male honey thread fish build a large, very loose foam nest consisting of only one layer of bubbles , under which they spawn with a female lured after intensive courtship . The colorless and transparent eggs, which are relatively large for such a small fish with a diameter of almost a millimeter, are collected by the male with his mouth and brought together in a so-called spawning lump . After just a few hours, the eggs first turn light yellow and turn dark gray as the larvae develop . Depending on the water temperature, the black colored larvae hatch after 24 to 48 hours. For one or two days she will keep the male close together and defend the nest. Then the fry swim free and the male's brood care system goes out.
Cultivated form
In addition to the wild-colored honey gourami, there is also a lemon-yellow (“golden”) cultivated form in which the beige basic color of the body is replaced by bright yellow. Probably due to a mutation, the melanophores are greatly reduced, which is why the longitudinal ligament is much less pronounced than that of the wild form. Even during the courtship phase, the males do not get a black breast. The cultivated form probably originated in the late 1980s or early 1990s. Since the late 2000s there has been another special form of the golden cultivated form, “FireRed”. It largely corresponds to the gold shape, the red tones in the softly radiating parts of the dorsal and anal fin appear stronger. It is still unclear whether this can really be explained by the cultivated form or whether this is due to a special diet. The biggest difference to the gold form is that the males develop their splendid coloration at half size and show it permanently.
Importance to humans
In their homeland, honey thread fish are used as dried fish or as fish meal for human consumption. Since they were first imported to Europe (1962), honey thread fish have been popular aquarium fish , from which two color deficiency mutations were formed as breeding breeds (a yellow and a red-orange form).
Systematics
The honey threadfish was described by Hamilton in 1822 as Trichopodus chuna . The first description is not based on a type specimen , only a drawing and a brief morphometric description in the "Gangetic Fishes". The type locality is also not known; Hamilton indicates the " Ganges ". Hamilton had described the species twice in the same work. One female as Trichopodus chuna , one male as Trichopodus sota . The Indian ichthyologist Menon was the first revising author to establish the species name Colisa chuna and put Colisa sota in the synonymy . The genus and species names are taken from the local language. In fact, it turned out that Trichopodus was preoccupied and therefore the next valid name had to be used, Trichogaster . Menon could not act as the first revising author either because he made false assumptions.
Synonyms : Colisa chuna , Colisa sota , Polyacanthus chuna , Trichogaster chuna , Trichopodus chuna , Trichopodus sota , Trichopodus soto . The naming Trichogaster for this genus is now widely recognized and is only rejected by a few aquarists.
literature
- Michael Kokoscha: Labyrinth Fish . Ulmer Verlag, Stuttgart 1998, ISBN 3-8001-7431-6 .
Web links
- Honey gourami on Fishbase.org (English)
- Colisa chuna in the "Catalog of Fishes"
Individual evidence
- ↑ J. Krause: Observations on the foam nest function in the home of Trichogaster lalius and Trichogaster chuna . In: AT . 1976, p. 387 .
- ↑ Wolfgang Löll: A new honey gourami, In: Aqualog News 98, pp. 15-16
- ^ Francis Buchanan-Hamilton: An account of the fishes found in the river Ganges and its branches . i-vii + 1-405, pls. 1-39. Edinburgh and London 1822.
- ^ AGK Menon: Check list - fresh water fishes of India . In: Records of the Zoological Survey of India (Ed.): Miscellaneous Publication, Occasional Paper . No. 175: i-xxviii +1-366, 1999.
- ↑ Hans-Joachim Paepke: Colisa chuna or Colisa sota . For the scientific naming of honey gourami (Teleostei: Acanthopterygii: Perciformes: Belontiidae). In: State Museum for Animal Science in Dresden (Ed.): Zoological treatises . Vol. 49, No. 11 , 1997, pp. 185-192 .