Melanorivulus

 

Untergattung Costa 2006 / Gattung Costa 2011 / Untergattung Huber 2012 / Gattung Costa 2017

 

 

 

Type species:  Melanorivulus punctatus 

 

Verbreitung: Brasilien, Bolivien, Paraguay und Argentinien. 

 

 

 

 

 

 

 

 

 

 

 

 

Melanorivulus kayabi  

Phylogenetic position and taxonomic status of Anablepsoides, Atlantirivulus, Cynodonichthys, Laimosemion and Melanorivulus (Cyprinodontiformes: Rivulidae)

Wilson J. E. M. Costa 2011

A maximum parsimony analysis of a combined set of mitochondrial and morphological data available in the literature for 33 rivuline taxa and three outgroups confirms Rivulus as a paraphyletic assemblage. In order to adjust a generic classification to our present phylogenetic knowledge on rivuline relationships, the following taxonomic changes are proposed: Rivulus, restricted to two species endemic to Cuba, is hypothesized to be the most basal rivuline lineage, distinguished from all other non-annual rivulines by having all hypurals fused into a single plate, neural prezygapophysis of caudal vertebrae rudimentary, fourth ceratobranchial teeth absent, about 50 % of the anterior portion of the caudal fin covered by scales, four neuromasts on the anterior supraorbital series, and a black round spot with white margin on the dorsoposterior portion of the caudal peduncle in females; Anablepsoides, Atlantirivulus, Laimosemion, Melanorivulus and Cynodonichthys, previously classified as subgenera of Rivulus, are considered as valid genera; Laimosemion, including 24 species from northern South America, constitutes the sister group to a clade comprising Melanorivulus, Cynodonichthys, Anablepsoides, Atlantirivulus, and all annual rivuline genera, which is supported by a well-developed dorsal process of the urohyal and an expanded lateral articular facet of the first hypobranchial; Melanorivulus, comprising 34 species from central and northeastern South America, Cynodonichthys with 27 species from Central America and Trans-Andean South America, Anablepsoides with 42 species from northern and northeastern South America and Smaller Antilles, and Atlantirivulus, with 11 species endemic to the eastern Brazilian coastal plains are diagnosed by combinations of morphological characters, including osteology, cephalic laterosensory system and colour patterns.

Huber, J.H., Reappraisal of the Phylogeny of Rivulus and its Allied focused on External Characters. Killi‐ Data Series 2012, 9‐25, 3 figs., 2 tabs.

Abstract: In the present study all known to date phylogenetic lineages encompassing the genus Rivulus in the large sense and its relatives, 44 in total, are benchmarked against a very long list of external characters involving global and detailed morphology of each, plus some characters related to biology, behavior and ecology, plus a few characters concerning the vertebrae counts and their structure. The parsimony analysis for these 144 characters results in 3 trees only, very much in line with the global stability of major lineages and the consensus tree produces bootstrap values that are much higher than previously released studies with morphological and osteological characters. In the resulting tree, outside Kryptolebias already separated in 2004, the genus Rivulus in the large sense is shown as a monophyletic assemblage like in the molecular study by Murphy, Thomerson & Collier (1999), with annual and non‐ annual species separated, but unlike Costa (2011) who used both morpho‐osteological and molecular combined characters. Apart from the coherence of the genus Rivulus in a large sense, the analysis newly suggests the primitive position of Millerichthys, the monophyly of major annual subclades, and the phylogenetic relationship of a clade of 3 subgenera of Rivulus, namely Prorivulus, Atlantirivulus, Melanorivulus in line with a previous palaeo‐bridge hypothesis and the minor osteological diagnostic characters that were forwarded for these 3 taxa should be deepened and re‐evaluated. Two other subunits of Rivulus, namely Anablepsoides and Oditichthys, are atypically placed in the tree, but their 2 type species were not studied by Costa (2011) and that too would need re‐evaluation. Finally several phylogenetic lineages belonging to the huge ‐and very poorly known‐ Amazon basin ends up in an unstable position and more material and characters are thought necessary for further research of this very difficult group of fish.

 

 

Melanorivulus Arten

 

Melanorivulus apiamici (W. J. E. M. Costa, 1989) 

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), pp. 79-88 (aqua)

Abstract:

A new species of Melanorivulus is described from the middle rio Paraná basin, São Paulo state, Brazil. Melanorivulus polychromus, new species, is found in a tributary of the left bank of the rio Paraná basin, the rio São José dos Dourados. It differs from all congeners by the combination of a metallic green to light green ground colour in males, with 6-8 oblique red bars forming chevronlike rows, the chevron tips along the midline of the body pointing toward the head, and irregular narrow red lines and incomplete red bars along the lower half of the body. Melanorivulus apiamici, also endemic from the middle rio Paraná basin, is redescribed.

 

Melanorivulus atlanticus W. J. E. M. Costa, Bragança & Ottoni, 2015 

A new miniature killifish of the genus Melanorivulus (Cyprinodontiformes: Rivulidae) from the coastal plains of north-eastern Brazil (Senckenberg)

Abstract:

Melanorivulus atlanticus, new species, is described on the basis of specimens collected in the coastal plains of north-eastern Brazil, constituting the first record of the genus for the Atlantic Forest biogeographical province. The new species together M. decoratus and M. jalapensis form a clade of small species, not surpassing 20 mm SL, mainly diagnosed by the presence of five branchiostegal rays. Melanorivulus atlanticus differs from those two species by a narrow black border along the entire caudal fin in males and the presence of 2+1 neuromasts in the mandibular series, besides differing from all congeners by having sexually dimorphic pelvic fin, which is pointed and with seven rays in males, elliptical and with five rays in females. The description of M. atlanticus expands in 670 km to east the known geographic range of the genus.

 

Melanorivulus bororo (W. J. E. M. Costa, 2008)

Rivulus bororo and R. paresi, two new killifishes from the upper Paraguay River basin, Brazil (Teleostei: Rivulidae). Ichthyol. Explor. Freshwat. 18(4):351-357.

 

Melanorivulus crixas (W. J. E. M. Costa, 2007)

Five new species of the aplocheiloid killifish genus Rivulus, subgenus Melanorivulus, from the middle Araguaia River basin, central Brazil (Teleostei: Cyprinodontiformes: Rivulidae).

 

Melanorivulus cyanopterus (W. J. E. M. Costa, 2005)

Seven new species of the killifish genus Rivulus (Cyprinodontiformes: Rivulidae) from the Paraná, Paraguay and upper Araguaia river basins, central Brazil. Neotrop. Ichthyol. 3(1):69-82.

 

Melanorivulus dapazi (W. J. E. M. Costa, 2005)

Seven new species of the killifish genus Rivulus (Cyprinodontiformes: Rivulidae) from the Paraná, Paraguay and upper Araguaia river basins, central Brazil. Neotrop. Ichthyol. 3(1):69-82.

 

Melanorivulus decoratus (W. J. E. M. Costa, 1989)

Descricao de cinco Especies de Rivulus das Bacias dos Rios Parana e Sao Francisco (Cyprionodontiformes, Rivulidae).Revta. Bras. Zool., 6 (3): 530, figs. 6-6a.

 

Melanorivulus egens (W. J. E. M. Costa, 2005)

Seven new Species of the Killifish Genus Rivulus (Cyprinodontiformes: Tivulidae) from the parana, Paraguay and upper Araguaia River basins, central Brasil. Neotropical Ichthyology, 3 (1). 80, fig. 11.

 

Melanorivulus faucireticulatus (W. J. E. M. Costa, 2008)

Type locality: Überflutungsebene des Bonfim River, obere Claro River Drainage, oberes Parana River Becken. Straße Go-516, 10 km westlich der Stadt Perolandia. ( 17° 31´31´´ S; 52° 07´52´´W )

 

Melanorivulus flavipinnis W. J. E. M. Costa, 2017 

Three new species of the killifish genus Melanorivulus from the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae)

Abstract:

Three new species are described from the Neotropical region comprising the Cerrado savannas of the central Brazilian plateaus, which is among the most important biodiversity centres in the world. These species are considered closely related to M. dapazi from the same region, with which they share the presence of a rudimentary interarcual cartilage and a dark reddish brown distal margin on the male anal fin. The group comprising M. dapazi and the three new species is here named as the M. dapazi species group. Melanorivulus ignescens sp. n., from the upper Rio Araguaia basin, is distinguished from all other species of the M. dapazi group by the anal-fin colour pattern in males; M. flavipinnis sp. n. and M. regularis sp. n. from the Rio Paraguai basin are distinguished from all other congeners of the M. dapazi group by the colour pattern of the caudal fin and number of scales in the longitudinal series, respectively. 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, but also indicates that osteological characters may be informative for species diagnosis. This study confirms the high diversity of species of Melanorivulus in the central Brazilian Cerrado plateaus already reported in previous studies, indicating that endemic species are often restricted to short segments of a single river drainage.

 

Melanorivulus formosensis (W. J. E. M. Costa, 2008)

Rivulus formosensis, a new aplocheiloid killifish from the upper Corrente River drainage, upper Paraná River basin, central Brazil (Cyprinodontiformes: Rivulidae) 

Abstract:

Rivulus formosensis, new species of the subgenus Melanorivulus, is described from the upper Corrente River drainage, a part of the Paranaíba River drainage of the upper Paraná River basin, central Brazil. It is considered a member of the R. pictus clade, which is diagnosed by the flank being intense greenish blue, to purplish blue above anal-fin base in males. It is distinguished from other species of Melanorivulus by a unique color pattern consisting of Y-shaped red marks on the flank in males. 

 

Melanorivulus giarettai (W. J. E. M. Costa, 2008)

Rivulus giarettai, a new killifish from the Araguari River drainage, upper Paraná River basin, Brazil (Cyprinodontiformes: Rivulidae)

Abstract:

Rivulus giarettai, new species, from the Araguari river drainage, upper rio Paraná basin, Brazil, is described. This is the first record of a rivulid in tributaries of the left bank of the Paranaíba river. Rivulus giarettai differs from all other species of the subgenus Melanorivulus by possessing a unique color pattern on flank in males, in which red pigmentation is arranged to form a vermiculate pattern. It is similar to species endemic to the central Brazilian plateau in having ventral process of angulo-articular vestigial, first epibranchial curved, and flank intense greenish blue or greenish golden, to purplish blue above anal-fin base in males; it differs from central Brazilian plateau species by a combination of reduction of black pigmentation on head and humeral region in males, 34-36 scales on the longitudinal series, 30-32 caudal-fin rays, 3-4 vomerine teeth, and caudal fin with bars in both sexes. 

 

Melanorivulus ignescens W. J. E. M. Costa, 2017 

Three new species of the killifish genus Melanorivulus from the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae)

Abstract:

Three new species are described from the Neotropical region comprising the Cerrado savannas of the central Brazilian plateaus, which is among the most important biodiversity centres in the world. These species are considered closely related to M. dapazi from the same region, with which they share the presence of a rudimentary interarcual cartilage and a dark reddish brown distal margin on the male anal fin. The group comprising M. dapazi and the three new species is here named as the M. dapazi species group. Melanorivulus ignescens sp. n., from the upper Rio Araguaia basin, is distinguished from all other species of the M. dapazi group by the anal-fin colour pattern in males; M. flavipinnis sp. n. and M. regularis sp. n. from the Rio Paraguai basin are distinguished from all other congeners of the M. dapazi group by the colour pattern of the caudal fin and number of scales in the longitudinal series, respectively. 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, but also indicates that osteological characters may be informative for species diagnosis. This study confirms the high diversity of species of Melanorivulus in the central Brazilian Cerrado plateaus already reported in previous studies, indicating that endemic species are often restricted to short segments of a single river drainage.

 

Melanorivulus illuminatus (W. J. E. M. Costa, 2007)

Rivulus illuminatus, a new killifish from the serra dos Caiapós, upper rio Paraná basin, Brazil (Teleostei: Cyprinodontiformes: Rivulidae). Ichthyol. Explor. Freshwat. 18(3):193-198.

 

Melanorivulus imperatrizensis D. T. B. Nielsen & C. S. Pinto, 2015 

Melanorivulus imperatrizensis, a new species of killifish (Cyprinodontiformes: Rivulidae) from the rio Tocantins basin, Brazil, pp. 136-143

Abstract:

Melanorivulus imperatrizensis, new species, collected in a small spring, at the middle rio Tocantins basin, northeast Brazil, is described. Melanorivulus imperatrizensis differs from all other species of the genus Melanorivulus by possessing all fins orange (vs. orange fins absent in other species of Mel­anorivulus or orange distal stripe on M. dapazi). The hypothesized close relationship between M. imperatrizensis and M. parnaibensis suggests a historical biogeographic relationship between Southern Amazonian tributaries and Rio Parnaíba.

 

Melanorivulus jalapensis (W. J. E. M. Costa, 2010) 

Rivulus jalapensis, a new killifish from the Tocantins River basin, central Brazil (Cyprinodontiformes: Rivulidae)

Abstract:

Rivulus jalapensis, new species, from the Sono River drainage, Tocantins River basin, central Brazil, is described. It is hypothesized to be closely related to R. decoratus from the São Francisco River basin by both species sharing the presence of five branchiostegal rays and small maximum size as adult. Sister group species of the Rivulidae occurring in small sections of the Tocantins basin and in eastern tributaries of the São Francisco River may have been originated by the uplift of the eastern terrains of the São Francisco basin during the early Cenozoic. Rivulus jalapensis is distinguished from all other species of the subgenus Melanorivulus by the color pattern of the unpaired fins in females, in which there are alternating dark gray bars and transverse series of light gray or white round spots. Rivulus jalapensis is distinguished from R. decoratus by the presence of a dark red stripe on the distal margin of the anal fin and the absence of a broad dark gray stripe on the ventral margin of the caudal fin in males.

 

Melanorivulus javahe (W. J. E. M. Costa, 2007)

Five new species of the aplocheiloid killifish genus Rivulus, subgenus Melanorivulus, from the middle Araguaia River basin, central Brazil (Teleostei: Cyprinodontiformes: Rivulidae). Aqua Int. J. Ichthyol. 13(2):55-68.

 

Melanorivulus karaja (W. J. E. M. Costa, 2007)

Five new species of the aplocheiloid killifish genus Rivulus, subgenus Melanorivulus, from the middle Araguaia River basin, central Brazil (Teleostei: Cyprinodontiformes: Rivulidae). Aqua Int. J. Ichthyol. 13(2):55-68. 

 

Melanorivulus kayabi (W. J. E. M. Costa, 2008)

Rivulus kayabi, a new killifish from the Tapajós river basin, southern Brazilian Amazon (Cyprinodontiformes: Rivulidae). Ichthyol. Explor. Freshwat. 18(4):345-350. (Ref. 76937)

 

 

 

Melanorivulus kayabi  "Nova-Mutum-Rio-Tapajos HvdB 2015/18"

 

 

Melanorivulus kayapo (W. J. E. M. Costa, 2006)

Rivulus kayapo n. sp. (Teleostei: Cyprinodontiformes: Rivulidae): a new killifish from the serra dos Caiapós, upper rio Araguaia basin, Brazil. Zootaxa 1368:49-56.

 

Melanorivulus kunzei W. J. E. M. Costa, 2012 

Two new species of Melanorivulus from the Caiapós hill, upper Araguaia river basin, Brazil (Cyprinodontiformes: Rivulidae)

Abstract:

Melanorivulus ubirajarai, new species, and Melanorivulus kunzei, new species, are described from the upper Araguaia river basin, central Brazil; both are considered as closely related to other species endemic from the same area. Melanorivulus ubirajarai shares with M. litteratus a unique colour pattern of caudal fin in females (short grey stripe between caudal spot and bar on the middle of the fin). Melanorivulus kunzei shares with M. kayapo a unique colour pattern of flank in males (irregular horizontal rows of red dots forming reticulate pattern). Melanorivulus ubirajarai is mainly distinguished from M. litteratus by having a distinct colour pattern of flank and dorsal fin in males, consisting of not overlapping chevron-like red oblique bars on the flank and rows of light grey spots on the dorsal fin in males, dorsal fin at vertical through the base of the 9th anal-fin ray, and 33-35 scales on the longitudinal series. Melanorivulus kunzei mainly differs from M. kayapo by having 29-30 caudal-fin rays and the presence of dark grey dots on the sub-distal portion of the dorsal fin and middle of caudal fin in males. The discovery of the two new species supports the recent report of a unique high species diversity of Melanorivulus in the area drained by rivers originating in the Caiapós hill. The combination of high species diversity with quick habitat loss makes rivulid species endemic to the Caiapós hill area highly threatened with extinction, deserving special concern.

 

Melanorivulus leali W. J. E. M. Costa, 2013 

A new killifish of the genus Melanorivulus from the upper Paraná river basin, Brazil (Cyprinodontiformes: Rivulidae)

Abstract:

 Melanorivulus leali, new species, from the Grande river drainage, south-eastern Brazil, is described. It differs from all other congeners by possessing a unique colour pattern, comprising red dots on body side arranged in chevron shaped rows, a broad dark grey stripe along the whole flank, flank light blue in males, dorsal and ventral portions of the caudal fin light orangish red in males, conspicuous orangish red bars on the middle of the caudal fin in males, and dorsal portion of the caudal-fin base with a small vertically elongated black spot. The presence of a black bar on the anterior and another on the posterior portion of the iris almost in contact with the pupil and the shape of the chevron-like rows of red spots on the flank, in which the angle is placed on the midline of the flank indicate that M. leali is more closely related to congeners endemic to the Paraná-Paraguay river system than to congeners endemic to the Amazonas river basin. This first record of the genus Melanorivulus from the Grande river drainage suggests that it may have formerly occupied a larger region of this basin, presently under severe process of deforestation and aquatic habitat decline.

 

Melanorivulus litteratus (W. J. E. M. Costa, 2005)

Seven new Species of the Killifish Genus Rivulus (Cyprinodontiformes: Rivulidae) from the Paraná, Paraguay and upper Araguaia River Basins, central Brazil. Neotropical Ichthyology, 3 (1), 75, figs. 6-7.

Type locality: Córrego do Sapo, upper rio Araguaia basin, road MT-100, 31 km south Alto Araguaia, município de Alto Araguaia, estado de Mato Grosso, altitude 750 m, (central) Brasil.

Melanorivulus megaroni (W. J. E. M. Costa, 2010) 

Rivulus megaroni, a new killifish from the Xingu River drainage, southern Brazilian Amazon (Cyprinodontiformes: Rivulidae)

Abstract:

Rivulus megaroni, new species, is described from the Xingu River drainage, southern Amazonas River basin, central Brazil. It is similar to other species of Melanorivulus endemic to the southern Amazonian tributaries of central Brazil by having a unique color pattern of flank in males, consisting of red marks arranged in a chevronlike pattern, in which the chevron vertex is placed on the ventral portion of the flank. The new species is distinguished from all other species sharing that color pattern by a combination of 34-36 scales in the longitudinal series, seven well-developed pelvic-fin rays, chevron marks of flank arranged as oblique bars, absence of red pigmentation on the tip of the lower jaw, a horizontal series of white spots on the dorsal portion of the caudal fin in females, and caudal fin pink in males.

 

Melanorivulus modestus (W. J. E. M. Costa, 1991)

Redescriçào do Gênero Rivulus, com Notas sobre R. stellifer e R. compactus e a Descriçao de duas novas Especies do Brasil central. Revta. Brasil Biol., 51 (2): 329, figs. 1 A-B.

Type locality: rio Mutum, lower rio Tapajos, Municipio Comodoro, Mato Grosso (tributary to rio Mutum, when crossed by BR-364 road, 51 km from Vilhena, subseq.), Brasil.

 

Melanorivulus nigropunctatus (Volcan, Klotzel & Lanès, 2017)

and

Melanorivulus ofaie (Volcan, Klotzel & Lanès, 2017)

Melanorivulus nigropunctatus & M. ofaie • Two New Species of Melanorivulus (Cyprinodontiformes: Cynolebiidae) from Rio Verde drainage, Upper Rio Paraná Basin, Brazil

Abstract                               Zootaxa, 4236 (1): 82-94. 

Two new species of the genus Melanorivulus are herein described from the middle Rio Verde drainage, upper Rio Paraná basin, Mato Grosso do Sul, Brazil. Both new species are members of the Melanorivulus pictus clade, diagnosed by having ventral process of angulo-articular vestigial and flanks intense greenish blue or greenish golden to purplish blue above anal fin base in males. Melanorivulus nigropunctatus, new species, from wetlands of a small drainage tributary of right side of the Rio Verde, differs from all other congeners by possessing black dots over the head and body in both sexes and pectoral fin orange with a dark grey margin in males. Melanorivulus ofaie, new species, is found in a similar environment, but at the opposite margin of the Rio Verde. It is distinguished by males presenting flank greenish blue to light blue, with seven to nine oblique chevron-like red bars, ventral portion of head whitish with dark brown spots, dorsal fin yellow with two to three transverse broad red oblique stripes and distal region red, anal fin light orangish yellow, basal area light blue with short red bars and distal portion with a dark red margin, and caudal fin yellow or orangish yellow with three to four vertical red bars in the dorsal and middle portions, sometimes with a orange distal margin. Both new species are considered endangered due to the loss and degradation of their habitat.

 

Melanorivulus paracatuensis (W. J. E. M. Costa, 2003)

Rivulus paracatuensis n. Sp. (Cyprinodontitormes: Rivulidae): a new rivuline species from the Rio Sao Francisco basin, Brazil. Aqua, Journal of Ichthyology and Aquatic Biology, 7 (1): 41, fig. 2.

Type locality: near Brasilândia de Minas, road MG 181, Rio aracatu floodplains, Rio Sao Francisco basin, Estado de

 

Melanorivulus paresi (W. J. E. M. Costa, 2008)

Rivulus bororo and R. paresi, two new killifishes from the upper Paraguay River basin, Brazil (Teleostei: Rivulidae). Ichthyol. Explor. Freshwat. 18(4):351-357

 

Melanorivulus parnaibensis (W. J. E. M. Costa, 2003)

A new Species of the Genus Rivulus Poey, 1860 from the Parnaiba River Basin, northeastern Brazil (Teleostei,Cyprinodontiformes, Rivulidae). Boletim Do Museu Nacional, Nova Série, Rio De Janeiro - Brasil, Zoologia, 511 (Sept. 22): 2, figs. 1-2.

Type locality: close to the road BR-135, 18km northeast of Sao Dimas, Parnaiba river basin, Piaui, (northeastern) Brasil.

 

Melanorivulus petrisecundi W. J. E. M. Costa, 2016 

Comparative morphology, phylogenetic relationships, and taxonomic revision of South American killifishes of the Melanorivulus zygonectes species group (Cyprinodontiformes: Rivulidae)

Abstract:

This study includes the first phylogenetic analysis for the M. zygonectes species group, a clade of small rivulid killifishes, endemic to an area comprising the transitional zone between the Amazon rain forest and the Cerrado savannah, in central and northeastern Brazil. The phylogenetic analysis integrating 59 morphological characters and DNA sequences highly supports monophyly of the group. Fourteen species are considered valid, including eleven previously described, of which most had their distribution areas and diagnoses revised on the basis of recent new collections, and three new species: M. kayabi from the Rio Tapajós and middle Rio Xingu drainages; M. rubroreticulatus from the lower Rio Xingu drainage; M. modestus from the upper Rio Tapajós drainage; M. megaroni from the upper and middle Rio Xingu drainage; M. salmonicaudus, M. spixi, new species, M. rubromarginatus, M. crixas, M. javaeh, M. karaja, and M. zygonectes, M. petrisecundi, new species, and M. wallacei, new species, from the Araguaia-Tocantins drainage system; and M. parnaibensis from the Rio Parnaíba basin. All clades contained in the M. zygonectes group have at least part of their members occurring in the Araguaia-Tocantins drainage system, a distribution pattern that is interpreted as evidence of a possible past distribution restricted to that area. This study once again supports the importance of using colour pattern characters of live specimens in systematics of aplocheiloid killifishes, since they were useful to diagnose species and sub-clades of the M. zygonectes group, besides increasing clade support when added to molecular data.

 

Melanorivulus pictus (W. J. E. M. Costa, 1989)

Descriçào de cinco Espécies de Rivulus das Bacias dos Rios Paranà e Sào Francisco (Cyprinodontiformes, Rivulidae). Revta. Bras. Zool., 6 (3): 525, figs. 2-2a.

Type locality: Fumal creek at road crossing, Formosa, Districto Federal, Brasil.

 

Melanorivulus pindorama W. J. E. M. Costa, 2012

Melanorivulus pindorama, a new killifish from the Tocantins River drainage, central Brazilian Cerrado (Cyprinodontiformes: Rivulidae)

Abstract:

Melanorivulus pindorama, new species, from the upper Tocantins River drainage, southern Amazonas River basin, central Brazil, is described. It is distinguished from all other congeners by having a unique colour pattern of flank and unpaired fins, consisting of pale grey spots overlapped by red reticulations on the flank and transverse rows of light grey spots on the dorsal fin in both sexes, and the presence of pale blue spots on the posterior portion of the anal fin, and caudal fin bluish grey without bars in males. Phylogenetic relationships of the new species are still unclear, but a possible close relationship with M. paracatuensis is hypothesized because of a superficial similarity in colour patterns, including the presence of a pale ground colour on flank with red pigmentation arranged in a reticulate pattern

 

Melanorivulus pinima (W. J. E. M. Costa, 1989)

Descriçào de cinco Espécies de Rivulus das Bacias dos Rios Paranà e Sào Francisco (Cyprinodontiformes, Rivulidae). Revta. Bras. Zool., 6 (3): 528, figs. 4-4a.

Type locality: município de Rio Verde, 37 km east of Jatai, BR 364 towards Goiânia, estado de Goiás, central Brasil.

 

Melanorivulus planaltinus (W. J. E. M. Costa & Brasil, 2008)

A new pelvicless killifish species of the genus Rivulus, subgenus Melanorivulus (Cyprinodontiformes: Rivulidae), from the upper Tocantins River Basin, Central Brazil. Copeia 2008(1):82-85.

 

Melanorivulus polychromus Nielsen,  Neves, Ywamoto & Passos, 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), pp. 79-88

 

Melanorivulus punctatus (Boulenger, 1895)

Viaggio del Dottor Alfredo Borelli nella Republica Argentina e nel Paraguay. Boll.Mus.Zool.Torino, 10 (196):3.                                                                                Type species:  Melanorivulus

Type locality: Colonia Risso, Paraguay.

 

Melanorivulus regularis W. J. E. M. Costa, 2017 

Three new species of the killifish genus Melanorivulus from the central Brazilian Cerrado savanna (Cyprinodontiformes, Aplocheilidae)

Abstract:

Three new species are described from the Neotropical region comprising the Cerrado savannas of the central Brazilian plateaus, which is among the most important biodiversity centres in the world. These species are considered closely related to M. dapazi from the same region, with which they share the presence of a rudimentary interarcual cartilage and a dark reddish brown distal margin on the male anal fin. The group comprising M. dapazi and the three new species is here named as the M. dapazi species group. Melanorivulus ignescens sp. n., from the upper Rio Araguaia basin, is distinguished from all other species of the M. dapazi group by the anal-fin colour pattern in males; M. flavipinnis sp. n. and M. regularis sp. n. from the Rio Paraguai basin are distinguished from all other congeners of the M. dapazi group by the colour pattern of the caudal fin and number of scales in the longitudinal series, respectively. 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, but also indicates that osteological characters may be informative for species diagnosis. This study confirms the high diversity of species of Melanorivulus in the central Brazilian Cerrado plateaus already reported in previous studies, indicating that endemic species are often restricted to short segments of a single river drainage.

  

Melanorivulus rossoi (W. J. E. M. Costa, 2005)

Seven new Species of the Killifish Genus Rivulus (Cyprinodontiformes: Rivulidae) from the Paraná, Paraguay and upper Araguaia River Basins, central Brazil. Neotropical Ichthyology, 3 (1), 74, fig. 5.

Type locality: 21.5 km southwest from Campo Grande on road BR-060, rio Inhanduí drainage, rio Paraná basin, município de Campo Grande, estado de Mato Grosso do Sul, (central) Brasil.

  

Melanorivulus rubromarginatus (W. J. E. M. Costa, 2007)

Five new species of the aplocheiloid killifish genus Rivulus, subgenus Melanorivulus, from the middle Araguaia River basin, central Brazil (Teleostei: Cyprinodontiformes: Rivulidae). Aqua Int. J. Ichthyol. 13(2):55-68.

 

Melanorivulus rubroreticulatus W. J. E. M. Costa, Amorim & Bragança, 2014 

A new miniature killifish of the genus Melanorivulus (Cyprinodontiformes: Rivulidae) from the Xingu river drainage, Brazilian Amazon

Abstract:

 Melanorivulus rubroreticulatus, new species, is described on the basis of material collected in the lower section of the Xingu river drainage, Brazilian Amazon. It is a member of a group endemic to the region encompassing the southern Amazonas river tributaries and the Parnaíba river basin. The new species is distinguished from other congeners of this group by the presence of broad red bars on the caudal fin in males, bars often interconnected to form reticulations, and short red bars contrasting with intense light blue ground colour on the anal-fin base. It represents the northern-most record for the group, besides being the only species occurring in the Amazon rain forest and possibly is also the smallest one, barely surpassing 25 mm of standard length.

 

Melanorivulus rutilicaudus (W. J. E. M. Costa, 2005)

Seven new Species of the Killifish Genus Rivulus (Cyprinodontiformes: Rivulidae) from the Paraná, Paraguay and upper Araguaia River Basins, central Brazil. Neotropical Ichthyology, 3 (1), 77, figs. 8-9.

Type locality: road BR-060, município de Serranópolis, rio Verde floodplains, rio Paraná basin, estado de Goiás, altitude 531 m, (central) Brasil.

 

Melanorivulus salmonicaudus (W. J. E. M. Costa, 2007)

Five new species of the aplocheiloid killifish genus Rivulus, subgenus Melanorivulus, from the middle Araguaia River basin, central Brazil (Teleostei: Cyprinodontiformes: Rivulidae). Aqua Int. J. Ichthyol. 13(2):55-68. 

 

Melanorivulus scalaris (W. J. E. M. Costa, 2005)

Seven new Species of the Killifish Genus Rivulus (Cyprinodontiformes: Rivulidae) from the Paraná, Paraguay and upper Araguaia River Basins, central Brazil. Neotropical Ichthyology, 3 (1), 78, fig. 10.

Type locality: tributary to the upper rio Sucuruí drainage, rio Paraná basin, altitude 810 m, município de Costa Rica, estado de Mato Grosso do Sul, (central) Brasil.

 

Melanorivulus schuncki (W. J. E. M. Costa & de Luca, 2011) 

Rivulus schuncki, a new species of the killifish subgenus Melanorivulus, from eastern Brazilian Amazon (Cyprinodontiformes: Rivulidae)

Abstract:

Rivulus schuncki, new species, is described from the Anauerapucu River drainage, lower Amazonas River basin, northern Brazil. It is distinguished from all other species of the subgenus Melanorivulus by its pointed snout in lateral view, 12 rows of scales around the caudal peduncle, bright green bars on the flank and caudal fin in males, flank dark brown with small light gray spots on ventral part in females, pelvic fin without dark gray or black anterior margin in females and by the absence of red bars or dots arranged in chevron-like pattern on flank. Rivulus schuncki constitutes the first record of the subgenus Melanorivulus north of the Amazonas River.

 

Melanorivulus spixi W. J. E. M. Costa, 2016 

Comparative morphology, phylogenetic relationships, and taxonomic revision of South American killifishes of the Melanorivulus zygonectes species group (Cyprinodontiformes: Rivulidae)

Abstract:

This study includes the first phylogenetic analysis for the M. zygonectes species group, a clade of small rivulid killifishes, endemic to an area comprising the transitional zone between the Amazon rain forest and the Cerrado savannah, in central and northeastern Brazil. The phylogenetic analysis integrating 59 morphological characters and DNA sequences highly supports monophyly of the group. Fourteen species are considered valid, including eleven previously described, of which most had their distribution areas and diagnoses revised on the basis of recent new collections, and three new species: M. kayabi from the Rio Tapajós and middle Rio Xingu drainages; M. rubroreticulatus from the lower Rio Xingu drainage; M. modestus from the upper Rio Tapajós drainage; M. megaroni from the upper and middle Rio Xingu drainage; M. salmonicaudus, M. spixi, new species, M. rubromarginatus, M. crixas, M. javaeh, M. karaja, and M. zygonectes, M. petrisecundi, new species, and M. wallacei, new species, from the Araguaia-Tocantins drainage system; and M. parnaibensis from the Rio Parnaíba basin. All clades contained in the M. zygonectes group have at least part of their members occurring in the Araguaia-Tocantins drainage system, a distribution pattern that is interpreted as evidence of a possible past distribution restricted to that area. This study once again supports the importance of using colour pattern characters of live specimens in systematics of aplocheiloid killifishes, since they were useful to diagnose species and sub-clades of the M. zygonectes group, besides increasing clade support when added to molecular data.

 

Melanorivulus ubirajarai W. J. E. M. Costa, 2012 

Two new species of Melanorivulus from the Caiapós hill, upper Araguaia river basin, Brazil (Cyprinodontiformes: Rivulidae)

Abstract:

Melanorivulus ubirajarai, new species, and Melanorivulus kunzei, new species, are described from the upper Araguaia river basin, central Brazil; both are considered as closely related to other species endemic from the same area. Melanorivulus ubirajarai shares with M. litteratus a unique colour pattern of caudal fin in females (short grey stripe between caudal spot and bar on the middle of the fin). Melanorivulus kunzei shares with M. kayapo a unique colour pattern of flank in males (irregular horizontal rows of red dots forming reticulate pattern). Melanorivulus ubirajarai is mainly distinguished from M. litteratus by having a distinct colour pattern of flank and dorsal fin in males, consisting of not overlapping chevron-like red oblique bars on the flank and rows of light grey spots on the dorsal fin in males, dorsal fin at vertical through the base of the 9th anal-fin ray, and 33-35 scales on the longitudinal series. Melanorivulus kunzei mainly differs from M. kayapo by having 29-30 caudal-fin rays and the presence of dark grey dots on the sub-distal portion of the dorsal fin and middle of caudal fin in males. The discovery of the two new species supports the recent report of a unique high species diversity of Melanorivulus in the area drained by rivers originating in the Caiapós hill. The combination of high species diversity with quick habitat loss makes rivulid species endemic to the Caiapós hill area highly threatened with extinction, deserving special concern.

 

Melanorivulus violaceus (W. J. E. M. Costa, 1991)

Redescriçào do Gênero Rivulus, com Notas sobre R. stellifer e R. compactus e a Descriçao de duas novas Especies do Brasil central. Revta. Brasil Biol., 51 (2): 331, figs. 2 C-D.

Type locality: rio das Mortes, lower rio Araguaia-rio Tocantins, Mato Grosso, Brasil (Municipio Chapadas dos Guimaraes, where crossed by BR-163 road at km 313, subseq.).

 

Melanorivulus vittatus (W. J. E. M. Costa, 1989)

Descriçào de cinco Espécies de Rivulus das Bacias dos Rios Paranà e Sào Francisco (Cyprinodontiformes, Rivulidae). Revta. Bras. Zool., 6 (3): 530, figs. 5-5a.

Type locality: 192 km southeast of Jatai, along road Sao Simao-Jataí, Goiás, central Brasil.

 

Melanorivulus wallacei W. J. E. M. Costa, 2016 

Comparative morphology, phylogenetic relationships, and taxonomic revision of South American killifishes of the Melanorivulus zygonectes species group (Cyprinodontiformes: Rivulidae)

Abstract:

This study includes the first phylogenetic analysis for the M. zygonectes species group, a clade of small rivulid killifishes, endemic to an area comprising the transitional zone between the Amazon rain forest and the Cerrado savannah, in central and northeastern Brazil. The phylogenetic analysis integrating 59 morphological characters and DNA sequences highly supports monophyly of the group. Fourteen species are considered valid, including eleven previously described, of which most had their distribution areas and diagnoses revised on the basis of recent new collections, and three new species: M. kayabi from the Rio Tapajós and middle Rio Xingu drainages; M. rubroreticulatus from the lower Rio Xingu drainage; M. modestus from the upper Rio Tapajós drainage; M. megaroni from the upper and middle Rio Xingu drainage; M. salmonicaudus, M. spixi, new species, M. rubromarginatus, M. crixas, M. javaeh, M. karaja, and M. zygonectes, M. petrisecundi, new species, and M. wallacei, new species, from the Araguaia-Tocantins drainage system; and M. parnaibensis from the Rio Parnaíba basin. All clades contained in the M. zygonectes group have at least part of their members occurring in the Araguaia-Tocantins drainage system, a distribution pattern that is interpreted as evidence of a possible past distribution restricted to that area. This study once again supports the importance of using colour pattern characters of live specimens in systematics of aplocheiloid killifishes, since they were useful to diagnose species and sub-clades of the M. zygonectes group, besides increasing clade support when added to molecular data.

 

Melanorivulus zygonectes (G. S. Myers, 1927)

An Analysis of the Genera of neotropical Killifishes allied to Rivulus. Ann. & Mag. Nat. Hist., 9 (19): 127.

Type locality: Vereda (Extrema) into Cannabrava, upper rio Tocantins basin, Goiás, Brasil.