Melanorivulus
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, 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. They inhabit shallow waters, generally deep, at the margins of streams in open or fairly open habitats like the Cerrado or Cerrado–Amazon transition. Many have tiny ranges and are seriously threatened.
Similar to closely related genera such as Anablepsoides, Atlantirivulus, Cynodonichthys and Laimosemion, Melanorivulus are jumpers and non-annual killifish.
Melanorivulus are small fish, with the largest species up in total length and the smallest less than. They are often quite colorful and some are kept in aquariums.
Species
Until 2011, Melanorivulus were included in Rivulus, and some prefer to maintain them in that genus.If recognized as a valid genus, there are currently 60 species in Melanorivulus:Melanorivulus amambaiensis Volcan, Severo-Neto & Lanés, 2018Melanorivulus apiamici Melanorivulus atlanticus Wilson [José Eduardo Moreira da Costa|W. J. E. M. Costa], Bragança & Ottoni, 2015Melanorivulus bororo Melanorivulus britzkei Nielsen, 2017Melanorivulus canesi Nielsen, 2017Melanorivulus crixas Melanorivulus cyanopterus Melanorivulus dapazi Melanorivulus decoratus Melanorivulus egens Melanorivulus faucireticulatus Melanorivulus flavipinnis Wilson José [Eduardo Moreira da Costa|W. J. E. M. Costa], 2017Melanorivulus formosensis Melanorivulus giarettai Melanorivulus ignescens W. J. E. M. Costa, 2017Melanorivulus illuminatus Melanorivulus imperatrizensis D. T. B. Nielsen & C. S. Pinto, 2015Melanorivulus interruptus Volcan, Severo-Neto & Lanés, 2018Melanorivulus ivinhemensis Volcan, Severo-Neto & Lanés, 2018Melanorivulus jalapensis Melanorivulus javahe Melanorivulus karaja Melanorivulus kayabi Melanorivulus kayapo Melanorivulus kunzei W. J. E. M. Costa, 2012Melanorivulus leali W. J. E. M. Costa, 2013 Melanorivulus linearis W. J. E. M. Costa, 2018Melanorivulus litteratus Melanorivulus megaroni Melanorivulus melanopterus Nielsen & Ohara, 2024Melanorivulus modestus Melanorivulus nelsoni Volcan, Severo-Neto & Lanés, 2017Melanorivulus nigromarginatus W. J. E. M. Costa, 2018Melanorivulus nigropunctatus Volcan, Klotzel & Luis Esteban [Krause Lanés|Lanés], 2017Melanorivulus ofaie Volcan, Klotzel & Lanés, 2017Melanorivulus paracatuensis Melanorivulus paresi Melanorivulus parnaibensis Melanorivulus petrisecundi W. J. E. M. Costa, 2016Melanorivulus pictus Melanorivulus pindorama W. J. E. M. Costa, 2012Melanorivulus pinima Melanorivulus planaltinus Melanorivulus polychromus D. T. B. Nielsen, Pedro Alvaro [Barbosa Aguiar Neves|P. A. B. A. Neves], Ywamoto & Passos, 2016Melanorivulus proximus W. J. E. M. Costa, 2018Melanorivulus punctatus Melanorivulus regularis W. J. E. M. Costa, 2017Melanorivulus rossoi Melanorivulus rubromarginatus Melanorivulus rubroreticulatus W. J. E. M. Costa, Amorim & Bragança, 2014Melanorivulus rutilicaudus Melanorivulus salmonicaudus Melanorivulus scalaris Melanorivulus schuncki Melanorivulus spixi W. J. E. M. Costa, 2016Melanorivulus terena Volcan, Severo-Neto & Lanés, 2024Melanorivulus ubirajarai W. J. E. M. Costa, 2012 Melanorivulus violaceus Melanorivulus vittatus Melanorivulus wallacei W. J. E. M. Costa, 2016