Simpsonichths alternatus was described by Costa & Brasil (1994) originally as Cynolebias alternatus and later by him transferred into Simpsonichthys.

Costa (2006) assigned this taxon to the subgenus Hypsolebias (Costa 2006) and after that Hypsolebias is then elevated to genus status (Costa 2011).

The genus classification of Hypsolebias is discussed because of unstable diagnoses. Huber considers Hypsolebias a subgenus of Simpsonichthys.

Hypsolebias alternatus is part of a group called the Flammeus species group.

It was found in a swamp close to the Rio Paracatú, part of the Rio Sao Francisco Basin, near Joao Pinheiro, Minas Gerais state, Brazil. It is possible that this location is connected to the river as it had non- annual fishes living in it at the time the discovery was made.

Coordinates approx: 17° 6'0.55"S 46° 2'46.87"W

This species can be productive, and the fry is small. Immediately after hatching, the fry should be fed with freshly hatched Artemia nauplii (brine shrimp) or better Paramecium. As most annual species do, they spawn by diving entirely into the substrate. It is best to provide a container with a lid on top in which a hole is made to allow the fish access. That container will need to have enough peat in it for the fish to dive completely into it. For most Hypsolebias species, egg development is complete after 8-10 weeks. However, it is wise also to check a few weeks earlier to see if any eggs have fully developed. Do not let the peat dry too far because the Hypsolebias like it moist. The development will be slower at storage temperatures between 21 and 24 Celsius and speed up at 25-29 Celsius. Before watering the eggs, put some eggs in the water of about 18-20 degrees Celsius to see if the eggs hatch

correctly. That usually happens within 2-6 hours. Then, if eggs hatched well and fry, swim correctly, bring all remaining peat in the water. You may need to re-pack the peat after pouring over the first group of fry to a larger tank. With regular water changes and sufficient food, the young will grow quickly, and after about 5-6 weeks, they can already produce their first eggs. Since this genus has an annual life cycle, the expected life span in captivity is not much more than 10 to 12 months. Their life expectancy is limited to when their pool still has water in the wild. This period can vary from 6 to 8 months.

Remark:

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Max. size 5.0 cm.
Dorsal 20.1,
Anal 22.5,
D/A 4,
LL scale count (average)23.5
Pre- dorsal length to % SL – 52.1 %

Costa, W.J.E.M. & G.C. Brasil. 1994. Trois nouveaux Poissons annuels de Genre Cynolebias (Cyprinodontiformes: Rivulidae) du Bassin du Rio Sao Francisco, Bresil. Rev.fr.Aquauriol. Herpetol., 21 (1-2): fig. 4.

Costa, W.J.E.M. 2006b. Descriptive Morphology and phylogenetic Relationships among species of the Neotropical annual Killifish genera Nematolebias and Simpsonichthys (Cyprinodontiformes: Aplocheiloidei: Rivulidae). Neotropical Ichthyology (Neotrop. ichthyol.), 4 (1), 1-26, 22 figs.

Nielsen, D.T.B., M. Martins, L.A. Medeiros, F.L. Origuela & A.M. Faour. 2014. Hypsolebias trifasciatus, a new species of annual fish (Cyprinodontiformes: Rivulidae) from the rio Preto, rio São Francisco basin, northeastern Brazil. Aqua, Journal of Ichthyology and Aquatic Biology, 20 (3): 131-138, figs.