Garcialebias nachtigalli, (Costa & Cheffe in Costa, 2006)

History

escribed in the genus Austrolebas

Discoverer(s): Wilson J.E.M. Costa, M.I. Landim and C. Moreira, July 19. 1997.

Etymology: in honor of Giovani Nachtigall Mauricio, Brasilian ornithologist, in appreciation of his efforts to collect annual fishes from Rio Grande do Sul, southeastern Brasil.

Comments: Costa & Cheffe (in Costa, 2006c) erect nachtigalli from populations they have previously assigned to nigrofasciatus ; note : Volcan et al. (2021) provisionally confirm that nachtigalli is molecularly subdivided in 2 clades, one of which including A. reicherti, but still maintian the species as valid within a pattern key. (Source: Killi Data Online, J.H. Huber)

Garcialebias nachtigalli (new combination.)

Garcialebias nachtigalli - male. Jaguarao Image made and donated for the use in this site by Olivier Buisson, France.
Garcialebias nachtigalli, male. Image made and donated by Dalton Nielsen, Brasil.
Garcialebias nachtigalli, habitat. Image made and donated by Matheus Volcan, Brasil.

Reproduction in general:

To breed most Austrolebias, you need a tank with about 10 to 25 liter water in it, a small jar or plastic container of about 10 to 15 cm high, a little bit of well-boiled peat moss, or coco-peat, and a water temperature between 18 and 24 C. It is wise to add a small filter to that tank and change the water regularly for 90 %. Bring one male and, if possible, two or more females in the tank and feed the fishes daily with live food like daphnia, red- and black mosquito larvae, and white worms. Austrolebias does not accept dry food quickly, and also, the prepared cow-heart is not preferred if live food is offered. If possible, breed this genus in larger tanks with more than one pair or trio and give some hiding places if you do so. When breeding with more than one male, you should also provide more than one spawning container. Every male must have one, and you will see they show interesting territorial behavior to attract females into their spawning place.

The male "flinders" around the female, displaying his fins high- up with the most intense colors. As the female is willing to spawn, she follows the male, pressing his head towards the layer of peat, and when the female contact the male's belly, both will dive into the peat layer. This layer should have a thickness of at least the length of the largest animal or, better, some deeper so they can dive entirely into it.

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

 

In the wild, Austrolebias live in colder environments during the wintertime. Temperatures in Uruguay, Paraguay, and Argentina can get very low. Incubation time usually is six weeks if stored at high temperatures ( 25 C.) and more extended if kept at lower temperatures. The development can last five to six months also. So it is wise to check the eggs regularly to see if the eyes inside the eggs are fully developed and the iris is well visible. When "eyed-up," put a part of the peat with the eggs in water at cool (ca. 18 C) temperature. If the fry usually hatches- and swims within a few hours, wet the rest of the peat. After hatching, feed the fry immediately with freshly born Artemia nauplii. A day or so later, I pour the water together with the fry off and place them in a well-filtered tank without any peat moss to grow up. Austrolebias are not used to strong currents, and juveniles can die if turbulence is too strong. The remaining peat will still have eggs inside that are not ready to hatch yet. Re-pack the peat and store it for some extra time. This hatching delay is nature's answer to short rain showers that fill pools only temporarily, followed by another dry period. Such an event would kill the entire population of the species in that area if all eggs were hatched with first rains. These (late) eggs will hatch later, sometimes very much later, and the fishes that were born earlier 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 applies to most Austrolebias. However, if the above Austrolebias- species have different behavior or extreme adult size, find these adaptions below in this chapter under <remarks>.

Remarks;

There are no reports yet on the reproduction of this species but it can be assumed that it does not differ from the general breeding method described above.


Variations
   

Map
   

Meristics
Max. size 5.5 cm.
Dorsal 21.0,
Anal 23.5,
D/A 3.0
LL scale count (average) 27.0
Pre- dorsal length to % SL – 52.4 %
Depth to % SL – 40.1 %
 

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): 133, fig. 50.

Volcan, M.V., L.E.K. Lanés & A.C. Gonçalves. 2014. Austrolebias bagual, a new species of annual fish (Cyprinodontiformes: Rivulidae) from southern Brazil. Aqua, Journal of Ichthyology and Aquatic Biology, 20 (4) (October): 161-172, figs.

Alonso F., G.E. Terán, W.S. Serra Alanís, P. Calviño, M.M. Montes, I.D. Carcía, J.A. Barneche, A. Almirón, L. Ciotek, P. Giorgis, J. Casciotta, 2023. From the mud to the tree: phylogeny of Austrolebias killifishes, new generic structure and description of a new species (Cyprinodontiformes: Rivulidae) Zool. Journ. of the Linnean Society, XX, 1-30, Fig. 15, Tab. 2.