Pachypanchax patriciae

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Pachypanchax patriciae
Superordinate : Earfish relatives (Atherinomorphae)
Order : Toothpies (Cyprinodontiformes)
Subordination : Aplocheiloidei
Family : Aplocheilidae
Genre : Pachypanchax
Type : Pachypanchax patriciae
Scientific name
Pachypanchax patriciae
Loiselle , 2006

Pachypanchax patriciae is afish that livesin Madagascar . It is named after the environmentalist Patricia Yazgi.

distribution and habitat

The range of the species extends over two different types of landscape, the monsoon forest in the area of ​​the Sambirano in the northwest and the deciduous forest in the far north of Madagascar. The two habitats are separated by the Ifasy .

In the Sambirano forest , P. patriciae inhabits small rivers such as the Ampandra and Manehoko. Their water is colored by tannins and is relatively acidic with a pH of five to six. It is very soft with less than one degree of German hardness (<18  ppm ) and has a very low conductance value , between 19 and 24 μS / cm². The bottom of the water consists of compacted clay or sand and is covered with detritus . In the shallow water there are large populations of an arum family ( Typhonodorum lindleyanunm ) and water lilies ( Nymphaea ), but otherwise hardly any aquatic plants.

The northern habitat of P. patriciae is characterized by the three large rivers Ifasy, Mahavavy du Nord and Mananjeba . Their water balance is subject to strong seasonal fluctuations and they have extensive floodplains with a large number of shallow ponds and lakes ( Matsabory ). These waters can be both clear and cloudy, but they are not tannic in color. Their pH is in the weakly acidic range between 6.5 and 7.2. With two to four degrees of German hardness and a conductivity of 38 to 74 μS / cm², they are a bit harder and more conductive than the habitats in the Sambirano area. P. patriciae can only be found in these lakes and small tributaries of the three rivers; it does not inhabit the large rivers themselves.

In both habitats, the species shares its habitat with juvenile specimens of Oreochromis mossambicus , a species of cichlid . In the deeper water there are also the Madagascar glitter cichlid ( Paratilapia polleni ), the flat-headed goby ( Glossogobius giuris ), Ptychochromis oligacanthus and a representative of the river eels , Anguilla bicolor .


This Pachypanchax species, with the shape typical of the genus, reaches a standard length of about 52 millimeters. The dorsal fin begins over the middle between the ninth and tenth or the tenth and eleventh ray of the anal fin . The caudal fin has white iridescent edges, the anal fin is also bordered in white. Nine to eleven gill trap processes are located on the first gill arch. There is a red and a blue color form which are only expressed through the males. The proportion of the population of the red form decreases towards the north. P. patriciae has 30 to 32 scales along the lateral line .

Fin formula :

  • Dorsal II – IV / 8–11
  • Anal II-III / 14-17
  • Pectorals 13-15
  • Ventral I / 5

Way of life

P. patriciae feeds on approach food as well as the larvae and nymphs of aquatic insects. Its predators are mainly piscivorous birds and dragonfly larvae , and other fish such as the Madagascar glitter cichlid and the flat-headed goby also prey on it. The breeding season probably extends over the entire rainy season.


In contrast to some other Pachypanchax , P. patriciae is not threatened by the pursuit of predatory neozoa . However, the clearing of the catchment areas of Ifasy, Mahavavy du Nord and Mananjeba endangers their water balance and thus the refuge areas of the species.



  • 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)

Individual evidence

  1. Four killifish described in review , Practical Fishkeeping, December 19, 2006 ( Memento of the original from December 6, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot /

Web links