Simpsonichthys chacoensis, Amato, 1986

History

Simpsonichthys chacoensis was described by Armato from the Chaco plains in Paraguay and as aquarium fish introduced by Dutch aquarists (Vandenberg 1994) after a collecting expedition.

Temporary waterbodies at Charca Topógrafo Acevedo, 14 km from radio command nº2 Americo Picco, 624 km nothwest of Asuncion towards Mariscal Estigarribbia, Nueva Ascunción, Paraguay.

Discovered on 20 August 1952 during the Expedition Estacion Biologia de Donana, Espana.

Replaced northerly by S. filamentosus, north- easterly by S. costai.
Is found together with Papiliolebias bitteri, Neofundulus ornatipinnis and Austrolebias monstrosus.

In Costa's revision(2006) of the genera Nematolebias and Simpsonichthys he devaluated the genus status of Spectrolebias to subgenus. In the same work he assigned 4 other species from the Simpsonichthys clan to this subgenus. These species are: S. reticulatus, S. costai, S. chacoensis and S. filamentosus. Since September 2008 another species is added to this subgenus. This was Simpsonichthys inaequipinnatus.

 
Simpsonichthys chacoensis - male. © Image made by F. Vermeulen.
Simpsonichthys chacoensis - female. © Image made by F. Vermeulen.

Reproduction

The Dutch Killie breeder Jan Willem Hoetmer was the first hobbyist that reported the reproduction of this species.
They seem not to difficult in reproduction and need only some extra attention during the first days as they need very small food as just hatched artemia or infusoria.

The way they spawn is, as most annual species do, by diving completely into the substratum.

 

This is best placed in a small jar or drinking glass at the bottom, filled with peat moss from at least the depth of the body length of the fishes.

After 5-6 weeks the fishes are capable to produce there first eggs if food was given sufficiently. The species is very beautiful if kept above a dark bottom and the light spots on black/blue background makes them look like a dark night under the stars.

Remarks :

 


Variations
Simpsonichthys chacoensis - juvenile male. © Image made by F. Vermeulen.
   

Map
     

Meristics

Max. size 5.0 cm.
Dorsal 20.4,
Anal 24.0,
D/A 5.3,
LL scale count (average)27.2
Pre- dorsal length to % SL – 50.7 %
Depth to % SL – 28.7 %

   

Literature
Armato, L.H. 1986. Seis Especies nuevas del Genero Cynolebias Stdr, 1876, de Uruguay y Paraguay (Cyprinodontiformes, Rivulidae). Com. Zool. Mus. Hist. Nat. Montevideo, 11 (162): 10. pl. 5 (fig.8), pl. 6 (fig.9).   Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae) Zootaxa 21 December 2007.