Austrolebias paranaensis, Costa, 2006

History

Austrolebias paranaensis was discovered by J.N. Taylor & G.R. Smith on August 26 1979 in the lower rio Parana in southern Paraguay at the border with Argentina. The description was released on may 26 2006 and done by Dr. Wilson Costa in his review of the genus.

Austrolebias paranaensis forms a speciesgroup with A. affinis, A. alexandri, A. carvalhoi, A. cyaneus, A. duraznensis, A. ibicuiensis, A. juanlangi, A. litzi, A. luzardoi, A. nigripinnis, A. patriciae, A. periodicus, A. toba and A. varzeae.

The exact location of terra typica is given as: 2 km east of Ayolas, Misiones, Paraguay. The types are stored at UFRJ Rio de Janeiro.

 

Austrolebias paranaensis - preserved male. Image taken from the original description.
Austrolebias paranaensis - preserved female. Image taken from the original description.

Reproduction

To breed most Austrolebias you need a tank that has about 10 to 25 litre water in it, a small jar or plastic container of about 10 to 15 cm high , a little bit of well boiled peatmoss or coco-peat and a watertemperature between 18 and 24 C. It is wise to add an small filter to that tank and change water on a regularly weekly basis for 90 %. Bring 1 male and, if possible, 2 or more females in the tank and feed the fishes daily with life food like daphnia, red- and black mosquito larvae and white worms. Austrolebias does not accept dry food easily and also heart is not taken if other live food is offered. If possible breed this genus in bigger tanks with more than one pair or trio and give some hiding places if you do so. In case of breeding with more than one male you also should provide more than one spawning container. Every male must have one and you will see they show nice territorial behaviour to attract females into there own spawning place.

The spawning take place during the whole fertile life of the fishes, starting at 5 to 6 weeks of age till they become old and weak or die by the lack of water in there natural environment. This will be within 8 to 11 months, depending on the temperature . Higher temperatures will trigger more rapid aging.

In the wild Austrolebias lives in cool environments during the wintertime. Temperatures in Uruguay, Paraguay and Argentina can get very low. Incubation time is normally 6 weeks if stored at high temperatures ( 25 C.) and longer if kept at lower temperatures. The development can take that 5 tot 6 months also. So it is wise to check the eggs on a regularly basis to see if the eyes inside the eggs are fully developed and the iris is good visible. If eyed- up, put a part of the peat with the eggs in water that has an cool (ca. 18 C) temperature. If the fry hatches normally and swim within a few hours you also wet the rest of the peat. After hatching I feed the fry immediately with Artemia nauplii. A day or so later I pour the water together with the fry off and place them in well filtered tank without any peatmoss to grow up. Austrolebias are not used to strong currents and juveniles can die if turbulece is to strong.The remaining peat will still have eggs inside that are not ready to hatch. You can repack the peat and store it for some extra time. This is nature's answer on short rain showers that fill pools only temporarily followed by another dry period. Such an event would kill the complete population of the species in that area if all eggs would have hatched with first rains. These (late) eggs will hatch later, sometimes very much later, and the older ones will eat these youngs.

As stated before, young’s are growing fast and will produce their first eggs after 5 to 6 weeks already, if not even sooner. This breeding information is applicable to most Austrolebias. If the above Austrolebias- species do have an different behaviour you will find below in this chapter under <remarks>.

Remarks;

 


Variations
   

Map
   

Meristics

Max. size 4.0 cm.
Dorsal 24.0,
Anal 23.0,
D/A 1.5,
LL scale count (average)26.0
Pre- dorsal length to % SL – 46.3 %
Depth to % SL – 34.1 %

Vertebrae count average 27.0

 

Literature
Costa, W.J.E.M. 2006. The South American annual Killifish Genus Austrolebias (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic Relationships, descriptive Morphology and Taxonomic Revision. Zootaxa, (1213): 69, fig. 28.