Melanorivulus regularis, male holotype.
Melanorivulus regularis, female paratype.
Given the large number of new species descriptions that show only a preserved specimen, we tend to get excited when researchers publish their findings using glorious, full-color photos. Such is the case with the latest work of Wilson JEM Costa, wherein he describes three new species of Melanorivulus killifishes from Brazil. This species are considered by Costa to be part of the M. dapazi species flock.
Even Costa takes a moment to remark on the importance of utilizing true, live coloration, noting, “All the new species are further unambiguously diagnosed by unique combinations of morphological characters, including meristic and morphometric data, and colour patterns. This study reinforces the importance of using live colour patterns to diagnose species and species groups of the genus Melanorivulus…”
Melanorivulus flavipinnis, male holotype
Melanorivulus flavipinnis, female paratype
While perhaps not the most drop-dead gorgeous killifishes the world has found, these small killies, with type specimens seldom measuring over 1 inch in standard length, would probably be welcome additions in any enthusiast’s tanks should they ever make their way into the aquarium hobby.
A quick review of related species suggests that these new fishes would probably be easy to keep and easy to breed, but likely prone to jumping. Similar species are given 2-3 year lifespans in captivity.
Melanorivulus ignescens, male holotype
Melanorivulus ignescens, female paratype
The most exciting part? Costa’s article, “Three new species of the killifish genus Melanorivulus from the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae),” has been published in ZooKeys as an open-access article, meaning you are free to download and read the species descriptions in their entirety!
In a related note, Costa, et. al., have also recently published an open-access article investigating the phylogeny of the genus Melanorivulus. “Molecular phylogeny and biogeography of the South American savanna killifish genus Melanorivulus (Teleostei: Aplocheilidae),” was published in the journal Vertebrate Biology, and is available for download here.
Image Credits:
Wilson JEM Costa, CC-BY-4.0
Reference & Source:
Costa W. JEM (2017) Three new species of the killifish genus Melanorivulus from the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae). ZooKeys 645: 51-70. https://doi.org/10.3897/zookeys.645.10920
Costa et. al (2016) Molecular phylogeny and biogeography of the South American savanna killifish genus Melanorivulus (Teleostei: Aplocheilidae). Vertebrate Biology 66 (3): 267–273. http://www.senckenberg.de/files/content/forschung/publikationen/vertebratezoology/vz66-3/04_vertebrate_zoology_66-3_costa_267-273.pdf
Melanorivulus relatives with aquarium notes at ItRainsFishes.net:
Melanorivulus dapazi
M. apiamici
M. pinima
M. scalaris
M. punctatus
