Pachypanchax
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Madagascar pike ( Pachypanchax omalonotus ) |
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| Scientific name | ||||||||||||
| Pachypanchax | ||||||||||||
| Myers , 1933 |
Pachypanchax (from " Panchax " and Greek pachys "thick", "rough"), German pike fish, is a genus offish from the order of the toothfish (Cyprinodontiformes)livingon Madagascar and the Seychelles . One species has also been introduced to Zanzibar . The German name " Hechtlinge " is imprecise and can lead to confusion, as the genera Aplocheilus and Epiplatys, some of which are very similar,and the Galaxiidae family arealso named.
habitat
The Pachypanchax species, which only occur in freshwater, inhabit small rivers, streams and shallow tributaries of lakes and mangrove swamps . Their home waters are almost at sea level up to 900 meters above sea level.
Appearance
The maximum total length for the members of this genus is about ten centimeters, but in most cases they remain smaller. The front part of the body is almost round in cross section and flattens out towards the rear. The relatively small fins are rounded. The dorsal fin has fewer fin rays than the anal fin and begins around the middle. Two thirds of the caudal fin is covered with small scales, starting from the base. The bases of the dorsal and anal fin are also scaled. On the top of the head, moved relatively far back, there is a vertex spot. The lower jaw of the upper mouth protrudes over the upper jaw. A row of relatively large conical teeth sit on each of the jaws. The scales along the sidelines are without pores.
Way of life
The surface-oriented animals feed on insects that have fallen into the water, aquatic invertebrates and insect larvae. Their preferred spawning sites are places with a coarse gravel bottom, aquatic plants and flooded roots from land plants standing on the shore. After a violent courtship, males and females take a position next to each other and curve their bodies in an S-shape. For a few moments the partners tremble intensely, then the female suddenly withdraws from the male and the ritual begins again. Relatively few eggs are deposited between aquatic plants during each mating round. The larvae hatch after ten days to two weeks, depending on the water temperature. Little is known about the ripening of juvenile fish in the wild; animals in captivity reach sexual maturity four to six months after hatching. After another year or two, they will have reached their final size.
Systematics
Three types have been recognized for some time:
- Madagascar pike ( P. omalonotus ) (Duméril, 1861) (Syn .: P. nuchimaculatus )
- Tüpfelhechtling ( P. playfairii ) (Guenther, 1866)
- P. sakaramyi (Holly, 1928)
Four more species were described in 2006
- P. varatraza LOISELLE, 2006
- P. patriciae LOISELLE, 2006
- P. sparksorum LOISELLE, 2006
- P. arnoulti LOISELLE, 2006
There are currently two competing hypotheses for the phylogenetic classification of the genus. One classifies Pachypanchax as a sister group to the genus Aplocheilus , the other as a sister group to a clade consisting of Aplocheilus and Epiplatys .
status
The sometimes extremely limited distribution of some Pachypanchax species makes them very susceptible to habitat changes. Several species are therefore classified as endangered by the IUCN .
swell
literature
- Steven M. Goodman, Jonathan P. Benstead: The Natural History of Madagascar , The University of Chicago Press, Chicago 2003, ISBN 0-226-30306-3 .
- Werner Neumann: Pachypanchax. In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. 2 volumes. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 736.
- Paul V. Loiselle: A review of the Malagasy Pachypanchax (Teleostei: Cyprinodontiformes, Aplocheilidae), with descriptions of four new species. Magnolia Press, 2006 ( Download , eng., PDF; 676 kB).
