Melanorivulus Explained

Melanorivulus is a genus of South American freshwater fish in the family Rivulidae. Most species are endemic to the Río de la Plata, eastern Amazon (west to Tapajós basin), Tocantins–Araguaia and São Francisco basins in Brazil, but a few members of this genus range west into Bolivia, south into Paraguay and Argentina, and east to Parnaíba and Sergipe in northeastern Brazil. Only M. schuncki occurs north of the Amazon River.^{[1] [2] [3] [4]} They inhabit shallow waters, generally deep, at the margins of streams in open or fairly open habitats like the Cerrado or Cerrado–Amazon transition.^[4] Many have tiny ranges and are seriously threatened.^[5]

Similar to closely related genera such as Anablepsoides, Atlantirivulus, Cynodonichthys and Laimosemion, Melanorivulus are jumpers and non-annual killifish.^{[6] [7] [8]}

Melanorivulus are small fish, with the largest species up in total length and the smallest less than .^[2] They are often quite colorful and some are kept in aquariums.^{[2] [4]}

Species

Until 2011, Melanorivulus were included in Rivulus,^[6] and some prefer to maintain them in that genus.^[7]

If recognized as a valid genus, there are currently 60 species in Melanorivulus:

• Melanorivulus amambaiensis Volcan, Severo-Neto & Lanés, 2018
• Melanorivulus apiamici (W. J. E. M. Costa, 1989)
• Melanorivulus atlanticus W. J. E. M. Costa, Bragança & Ottoni, 2015^[2]
• Melanorivulus bororo (W. J. E. M. Costa, 2008)
• Melanorivulus britzkei Nielsen, 2017
• Melanorivulus canesi Nielsen, 2017
• Melanorivulus crixas (W. J. E. M. Costa, 2007)
• Melanorivulus cyanopterus (W. J. E. M. Costa, 2005)
• Melanorivulus dapazi (W. J. E. M. Costa, 2005)
• Melanorivulus decoratus (W. J. E. M. Costa, 1989)
• Melanorivulus egens (W. J. E. M. Costa, 2005)
• Melanorivulus faucireticulatus (W. J. E. M. Costa, 2008)
• Melanorivulus flavipinnis W. J. E. M. Costa, 2017^[9]
• Melanorivulus formosensis (W. J. E. M. Costa, 2008)
• Melanorivulus giarettai (W. J. E. M. Costa, 2008)
• Melanorivulus ignescens W. J. E. M. Costa, 2017^[9]
• Melanorivulus illuminatus (W. J. E. M. Costa, 2007)
• Melanorivulus imperatrizensis D. T. B. Nielsen & C. S. Pinto, 2015^[10]
• Melanorivulus interruptus Volcan, Severo-Neto & Lanés, 2018
• Melanorivulus ivinhemensis Volcan, Severo-Neto & Lanés, 2018
• Melanorivulus jalapensis (W. J. E. M. Costa, 2010)^[11]
• Melanorivulus javahe (W. J. E. M. Costa, 2007)
• Melanorivulus karaja (W. J. E. M. Costa, 2007)
• Melanorivulus kayabi (W. J. E. M. Costa, 2008)
• Melanorivulus kayapo (W. J. E. M. Costa, 2006)
• Melanorivulus kunzei W. J. E. M. Costa, 2012^[5]
• Melanorivulus leali W. J. E. M. Costa, 2013^[12]
• Melanorivulus linearis W. J. E. M. Costa, 2018
• Melanorivulus litteratus (W. J. E. M. Costa, 2005)
• Melanorivulus megaroni (W. J. E. M. Costa, 2010)^[13]
• Melanorivulus modestus (W. J. E. M. Costa, 1991)
• Melanorivulus nelsoni Volcan, Severo-Neto & Lanés, 2017
• Melanorivulus nigromarginatus W. J. E. M. Costa, 2018
• Melanorivulus nigropunctatus Volcan, Klotzel & Lanés, 2017^[14]
• Melanorivulus ofaie Volcan, Klotzel & Lanés, 2017^[14]
• Melanorivulus paracatuensis (W. J. E. M. Costa, 2003)
• Melanorivulus paresi (W. J. E. M. Costa, 2008)
• Melanorivulus parnaibensis (W. J. E. M. Costa, 2003)
• Melanorivulus petrisecundi W. J. E. M. Costa, 2016^[15]
• Melanorivulus pictus (W. J. E. M. Costa, 1989)
• Melanorivulus pindorama W. J. E. M. Costa, 2012^[16]
• Melanorivulus pinima (W. J. E. M. Costa, 1989)
• Melanorivulus planaltinus (W. J. E. M. Costa & Brasil, 2008)
• Melanorivulus polychromus D. T. B. Nielsen, P. A. B. A. Neves, Ywamoto & Passos, 2016^[17]
• Melanorivulus proximus W. J. E. M. Costa, 2018
• Melanorivulus punctatus (Boulenger, 1895)
• Melanorivulus regularis W. J. E. M. Costa, 2017^[9]
• Melanorivulus rossoi (W. J. E. M. Costa, 2005)
• Melanorivulus rubromarginatus (W. J. E. M. Costa, 2007)
• Melanorivulus rubroreticulatus W. J. E. M. Costa, Amorim & Bragança, 2014^[18]
• Melanorivulus rutilicaudus (W. J. E. M. Costa, 2005)
• Melanorivulus salmonicaudus (W. J. E. M. Costa, 2007)
• Melanorivulus scalaris (W. J. E. M. Costa, 2005)
• Melanorivulus schuncki (W. J. E. M. Costa & de Luca, 2011)^[19]
• Melanorivulus spixi W. J. E. M. Costa, 2016^[15]
• Melanorivulus ubirajarai W. J. E. M. Costa, 2012 ^[5]
• Melanorivulus violaceus (W. J. E. M. Costa, 1991)
• Melanorivulus vittatus (W. J. E. M. Costa, 1989)
• Melanorivulus wallacei W. J. E. M. Costa, 2016^[15]
• Melanorivulus zygonectes (G. S. Myers, 1927)

Notes and References

1. Book: van der Sleen, P. . J.S. Albert . 2017 . Field Guide to the Fishes of the Amazon, Orinoco, and Guianas . Princeton University Press . 356 . 978-0691170749 .
2. Costa, W.J.E.M., Bragança, P.H.N. & Ottoni, F.P. (2015): A new miniature killifish of the genus Melanorivulus (Cyprinodontiformes: Rivulidae) from the coastal plains of north-eastern Brazil. Vertebrate Zoology, 65 (1): 31–35.
3. Bragança, P.H.N. . P.F. Amorim . W.J.E.M. Costa . 2012 . Geographic distribution, habitat, colour pattern variability and synonymy of the amazon killifish Melanorivulus schuncki (Cyprinodontiformes: Rivulidae) . Ichthyological Exploration of Freshwaters . 23 . 1 . 51–55 .
4. Costa, W.J.E.M. . P.F. Amorim . R.C. Rizzieri . 2016 . Molecular phylogeny and biogeography of the South American savanna killifish genus Melanorivulus (Teleostei: Aplocheilidae) . Vertebrate Zoology . 66 . 267–273 . 10.3897/vz.66.e31565 . 257198386 . free .
5. Costa, W.J.E.M. (2012): Two new species of Melanorivulus from the Caiapós hill, upper Araguaia river basin, Brazil (Cyprinodontiformes: Rivulidae). Ichthyological Exploration of Freshwaters, 23 (3): 211-218.
6. Costa, W.J.E.M. . 2011 . Phylogenetic position and taxonomic status of Anablepsoides, Atlantirivulus, Cynodonichthys, Laimosemion and Melanorivulus (Cyprinodontiformes: Rivulidae) . Ichthyological Exploration of Freshwaters . 22 . 3 . 233–249 .
7. Huber, J.H. . 2012 . Reappraisal of the Phylogeny of Rivulus and its Allied focused on External Characters . Killi-Data Series . 2012 . 9–25 .
8. Book: Berois, N. . G. García . R.O. de Sá . 2015 . Annual Fishes: Life History Strategy, Diversity, and Evolution . 16–19 . CRC Press . 9781482299717 .
9. Costa, W.J.E.M. (2017): Three new species of the killifish genus Melanorivulus from the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae). ZooKeys, 645: 51–70.
10. Nielsen, D.T.B. & Pinto, C.S. (2015): Melanorivulus imperatrizensis, a new species of killifish (Cyprinodontiformes: Rivulidae) from the rio Tocantins basin, Brazil. aqua, International Journal of Ichthyology, 21 (3): 136-143.
11. Costa, W.J.E.M. (2010): Rivulus jalapensis, a new killifish from the Tocantins River basin, central Brazil (Cyprinodontiformes: Rivulidae). Ichthyological Exploration of Freshwaters, 21 (3): 193-198.
12. Costa, W.J.E.M. (2013): A new killifish of the genus Melanorivulus from the upper Paraná river basin, Brazil (Cyprinodontiformes: Rivulidae). Vertebrate Zoology, 63 (3): 277-281.
13. Costa, W.J.E.M. (2010): Rivulus megaroni, a new killifish from the Xingu River drainage, southern Brazilian Amazon (Cyprinodontiformes: Rivulidae). Ichthyological Exploration of Freshwaters, 20 (4): 365-370.
14. Volcan, M.V., Klotzel, B. & Lanés, L.E.K. (2017): Two new species of Melanorivulus (Cyprinodontiformes: Cynolebiidae) from Rio Verde drainage, Upper Rio Paraná basin, Brazil. Zootaxa, 4236 (1): 82-94.
15. Costa, W.J.E.M. (2016): Comparative morphology, phylogenetic relationships, and taxonomic revision of South American killifishes of the Melanorivulus zygonectes species group (Cyprinodontiformes: Rivulidae). Ichthyological Exploration of Freshwaters, 27 (2): 107-152.
16. Costa, W.J.E.M. (2012): Melanorivulus pindorama, a new killifish from the Tocantins River drainage, central Brazilian Cerrado (Cyprinodontiformes: Rivulidae). Ichthyological Exploration of Freshwaters, 23 (1): 57-61.
17. Nielsen, D.T.B., Neves, P.A.B.A., Ywamoto, E.V. & Passos, M.d.A. (2016): Melanorivulus polychromus, a new species of killifish from the rio São José dos Dourados drainage, middle rio Paraná basin, southwestern Brazil, with a redescription of Melanorivulus apiamici (Cyprinodontiformes: Rivulidae). aqua, International Journal of Ichthyology, 22 (2): 79-88.
18. Costa, W.J.E.M., Amorim, P.F. & Bragança, P.H.N. (2014): A new miniature killifish of the genus Melanorivulus (Cyprinodontiformes: Rivulidae) from the Xingu river drainage, Brazilian Amazon. Vertebrate Zoology, 64 (2): 193-197.
19. Costa, W.J.E.M. & De Luca, A.C. (2011): Rivulus schuncki, a new species of the killifish subgenus Melanorivulus, from eastern Brazilian Amazon (Cyprinodontiformes: Rivulidae). Ichthyological Exploration of Freshwaters, 21 (4): 289-293.