This species was originally described as Simpsonichthys harmonicus.

W. Costa (2006) assigned many members of the genus Simpsonichthys to the subgenus Hypsolebias (Costa 2006). Hypsolebias was subsequently elevated to a genus (Costa 2011). According to some scientists, the separation of Hypsolebias from the genus Simpsonichthys is insufficiently substantiated and, therefore, debatable.

Discoverer(s): 

Wilson J.E.M. Costa, M.A. Barbosa, L. Alexandre and A. Oliveira, May 8. 2009.

Type locality: 

road BR-349, ca. 12 km of the left bank of São Francisco river, municipio de Bom Jesus da Lapa, Bahia state, altitude 437 m, (eastern) Brasil.

Etymology: 

harmonious (from Latin: harmonicus), in reference to the male color pattern.

Diagnosis: 

only separated from related components by minor morphometric characters.

Superspecies-components: 

H. adornatus, alternatus, brunoi, caeruleus, carlettoi, delucai, fasciatus, flammeus, fulminantis, gardneri, hamadryades, harmonicus, hellneri, longignatus, lopesi, magnificus, multiradiatus, ocellatus, picturatus, shibattai, splendissimus, tocantinensis, trifasciatus.

Hypsolebias harmonicus is described from the left floodplains of the middle Sao Francisco River about 12 km of the left river bank, close to the road BR-349, Bom Jesus de Lapa, Bahia, north- eastern Brazil. The habitat was a seasonal pool, surrounded by a typical vegetation of the Caatinga semi- arid region, about 50 cm deep and with turbid, brownish - yellow water. The species is considered to be close related to Hypsolebias magnificus and H. picturatus that also occur in the same region. The H. calettoi is also a member of this clade. The new species is distinguished from H. magnificus and H. picturatus by the combination of pectoral fin that reaching a vertical between bases of the fourth and fifth anal-fin ray in males: 21-22 caudal fin rays; caudal fin length 31.2-33.2 % SL in males; pre- pelvic length 44.2-47.6 % SL in males; 5-7 transverse rows of dots on dorsal fin, 6-8 on anal fin and 6-8 on caudal fin; bleu stripes on the distal portion of the dorsal finin males; and 13-16 bars on the flank in females.

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:

If this species shares also the breeding specific data it will be hard to bring eggs to development whitin less than 4 months. For H. magnificus I had expirienced a development time of at least 6 months and ocasionally more than one year. Only if stored under high temperatures of 28 C. or higher it was possible to get that done in a shorter time.

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Size approx. 4.5 cm. SL.
Dorsal 22-24 in males, 14-16 in females.
Anal 19-21 in males, 17-19 in females.
Caudal 21-22,
Pectorals 12-13,
Pelvic rays 5,
D/A 0.0,
LL scale count 26 - 27
Pre- dorsal length to % SL – 45.9 %
Depth to % SL – 35.9 %

Costa W.J.E.M, 2010. Simpsonichthys harmonicus, a new seasonal killifish from the Sao Francisco River basin, northern Brazil. (Cyprinodontiformes: Rivulidae)Ichthyol. Explor.Freshwaters, Vol. 21, No. 1, pp. 73-78, 2 figs., 1 tab. March 2010.

Costa, W.J.E.M. 2010e. Historical Biogeography of cynolebiasine annual Killifishes inferred from Dispersal-Vicariance Analysis. Journal of Biogeography (J. Biogeogr.), 37: 1995-2004.

Nielsen, D.T.B., M. Martins, L.A. Medeiros & R.R. Suzart. 2014. Hypsolebias shibattai, a new species of annual fish (Cyprinodontiformes: Rivulidae) from the rio São Francisco basin, northeastern Brazil. Aqua, Journal of Ichthyology and Aquatic Biology, 20 (1) (January): 27-34, figs.