scholarly journals A new Silver Dollar species of Metynnis Cope, 1878 (Characiformes: Serrasalmidae) from Northwestern Brazil and Southern Venezuela

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Rafaela Priscila Ota ◽  
◽  
Lúcia Helena Rapp Py-Daniel ◽  
Michel Jégu ◽  
◽  
...  

ABSTRACT A new Metynnis is described from the rio Negro in Brazil and Venezuela, and from black- or clearwater tributaries in Brazil including the rios Parauari, Uatumã, Trombetas, and Sucunduri (the latter belonging to the rio Madeira basin). The new species can be distinguished readily from all congeners by having a high concentration of dark chromatophores on the lateral line scales. It can be further distinguished by the combination of head length 24.3-27.5% of SL, 13-18 gill-rakers on upper limb and 16-24 gill-rakers on lower limb. The new species is most similar to and likely most closely related to Metynnis hypsauchen . These two species share a similar color pattern, body shape and sexual dimorphism of the anal fin. However, they differ in that M. hypsauchen has a lightly pigmented lateral line. The new species is also distinguished from M. hypsauchen by having 56-65 predorsal scales and 90-104 lateral line scales (vs . 36-54, and 65-82, respectively). A detailed osteological description of the new species is provided.

2014 ◽  
Vol 12 (2) ◽  
pp. 265-279 ◽  
Author(s):  
Rafaela P. Ota ◽  
Flávio C. T. Lima ◽  
Carla S. Pavanelli

A new Hemigrammusis described from the rio Paraguai and rio Madeira basins, Mato Grosso and Rondônia States, Brazil. The new species is characterized by possessing a wide dark horizontal stripe across the eye, a vertically elongated humeral blotch, and 4-5 gill-rakers on upper branch and 9-10 on lower. The new species can be easily diagnosed from H. lunatus, the sympatric and morphologically most similar congener, by the shape of humeral blotch and the number of gill rakers. Data of the type material of both Hemigrammus lunatus and H. maxillaris, as well as extensive examination of specimens, allowed us to conclude that H. maxillarisis a junior subjective synonym of H. lunatus. A redescription of H. lunatus, as well as a formal restriction of its type locality, is provided. A putative monophyletic group within Hemigrammus, composed by H. barrigonae, Hemigrammus lunatus, H. machadoi new species, and H. ulreyi, named Hemigrammus lunatus group, is proposed based on overall body morphology and color pattern. Additionally, a discussion on the biogeographical relationships between the rio Paraguai and rio Guaporé basins is provided.


Zootaxa ◽  
2009 ◽  
Vol 2262 (1) ◽  
pp. 53-68 ◽  
Author(s):  
ANDRÉ L. NETTO-FERREIRA ◽  
ANGELA M. ZANATA ◽  
JOSÉ L.O. BIRINDELLI ◽  
LEANDRO M. SOUSA

Two new species of Jupiaba Zanata are described from Brazil. Jupiaba iasy, new species, is described from rio Teles Pires and rio Jamanxim, tributaries of rio Tapajós, and from rio Aripuanã, in the rio Madeira drainage. It is distinguished from its congeners by its color pattern consisting of a single posteriorly displaced dark crescent-shaped humeral blotch, situated over the first 5 to 7 lateral line scales, and an inconspicuous dark spot at the end of caudal peduncle. It also differs from all remaining Jupiaba for the following combination of characters: 34-36 lateral line scales, 19–21 branched anal-fin rays, 8–10 predorsal scales arranged in a regular row, 6 horizontal series of scales above and 4 series below lateral line, body depth 32.3–36.1% of SL, and absence of filamentous rays in the first dorsal and anal-fin rays. Jupiaba paranatinga, new species, is described from rio Teles Pires, tributary of rio Tapajós. It is distinguished by having 34–35 lateral line scales, two vertically elongated humeral blotches, a conspicuous caudal spot at the end of the caudal peduncle, extending over 8–10 median caudal-fin rays, eye diameter 43.7–46.9% of HL, and relatively low body depth (31.3–35.5% of SL). Additionally, comments on the putative relationships of the new species with their congeners and an updated key to the species of the genus are provided.


Zootaxa ◽  
2019 ◽  
Vol 4577 (2) ◽  
pp. 335 ◽  
Author(s):  
RAFAELA P. OTA ◽  
FLÁVIO C. T. LIMA ◽  
MAX H. HIDALGO

We described herein a new Hemigrammus from the río Madre de Dios and rio Mamoré basins in southeastern Peru and Bolivia. The new species possess a color pattern similar to those belonging to the Hemigrammus lunatus species-group, i.e., a broad longitudinal dark stripe across the eye and a conspicuous, narrow dark stripe along the anal-fin basis. It can be easily diagnosed from the species belonging to this group by presenting the combination of the following characters: an oval, horizontally elongated humeral blotch, 6-7 upper branch and 10-12 lower branch gill-rakers, up to five cusps on broader maxillary teeth, and by lacking a midlateral dark stripe. Comments on its putative relationships are provided. Additionally, we updated the geographical distribution of Hemigrammus lunatus and H. machadoi based on an exhaustive survey of material deposited in collections. [Species Zoobank registration: urn:lsid:zoobank.org:act:A2ED5D61-8434-4A0F-BC5B-B496FB3DC191] 


Zootaxa ◽  
2010 ◽  
Vol 2405 (1) ◽  
pp. 63
Author(s):  
PEK KHIOK ANNIE LIM ◽  
HIROYUKI MOTOMURA ◽  
ALBERT CHUAN GAMBANG

A new species of large-sized brackishwater threadfin, Polydactylus luparensis, is described from the Batang Lupar River in Sarawak, Malaysia, Borneo on the basis of 5 specimens (610–715 mm standard length). The new species can be distinguished from all other Polydactylus by having 8 dorsal-fin spines, first spine tiny, second spine very strong (its width more than 5 times the width of remaining spines); 13 second dorsal-fin soft rays; 11 anal-fin soft rays; 12 pectoralfin rays, its length 22–24% (mean 23%) of SL, posterior tip not reaching a vertical through posterior tip of depressed pelvic fin; 6 pectoral filaments, fourth or fifth filament longest, its length 77–85% (mean 81%) of SL, posterior tip extending slightly beyond caudal-fin base; pored lateral-lined scales 67–75 (mean 71); lateral line unbranched, extending onto upper end of lower caudal-fin lobe; 6 scale rows above lateral line, 8 below; 14 gill rakers on upper limb, 18 on lower limb, 32 in total; occipital profile concave; posterior margin of maxilla extending considerably beyond a vertical through posterior margin of adipose eyelid; depth of posterior margin of maxilla 4–5% (mean 5%) of SL, greater than orbit diameter; well-developed swimbladder present; basal half of third to sixth pectoral filament white, becoming black distally. Polydactylus luparensis is currently known only from the mouth of the Batang Lupar River.


2009 ◽  
Vol 7 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Carla S. Pavanelli ◽  
Rafaela P. Ota ◽  
Paulo Petry

A new species of Metynnis is described from the rio Cuiabá and rio Manso drainages, in the upper rio Paraguay basin, Mato Grosso State, Brazil. This laterally compressed species, which rarely exceeds 140 mm in SL, is readily distinguished from other members of the genus Metynnis by having 100-110 lateral-line scales, 48-56 rows of scales above the lateral line, 32-36 circumpeduncular scales, 22-24 gill rakers, 38 vertebrae, singular color pattern, and relatively smaller snout, width, and head length.


2011 ◽  
Vol 9 (4) ◽  
pp. 697-707 ◽  
Author(s):  
William Benedito Gotto Ruiz ◽  
Oscar Akio Shibatta

Two new species of Microglanis are described from tributaries of upper-middle rio Araguaia, States of Mato Grosso and Goiás, Brazil. Microglanis oliveirai differs from its congeners by the short supraoccipital process not reaching the small anterior nuchal plate, and reduced number of gill rakers, lateral line pores, ribs, vertebrae, and caudal-fin rays. Microglanis xylographicus differs from its congeners by the presence of melanophores surrounding the neuromasts of the superficial lines, snout length 11.4-12.9% SL and body color pattern consisting of horizontal brown stripes similar to a wooden bark pattern. An identification key of Microglanis species from the Amazon basin is presented.


2021 ◽  
pp. 57-61
Author(s):  
L.S. Vieira ◽  
A.L. Netto-Ferreira

A new species (Microcharacidium bombioides sp. nov.) of the genus Microcharacidium Buckup, 1993 is described from the Rio Negro, Rio Trombetas, Rio Tapajós, tributaries of the Rio Madeira, and the middle Rio Amazonas. The new species is promptly distinguished from all congeners (Microcharacidium eleotrioides (Géry, 1960), Microcharacidium gnomus Buckup, 1993, and Microcharacidium weitzmani Buckup, 1993) by the presence of 12 circumpeduncular scales, 19 precaudal vertebrae, and 7 dark bars on the flanks connected to their contralateral parts both dorsally and ventrally; 2 short, dark suborbital stripes; all teeth on both jaws conical; 10–11 total dorsal-fin rays; and 3–4 perforated lateral line scales. An updated identification key for the genus is provided and the affinities of the new species with other Microcharacidium are discussed.


Zootaxa ◽  
2019 ◽  
Vol 4700 (4) ◽  
pp. 487-493 ◽  
Author(s):  
NATHÁLIA C. SOARES ◽  
RICARDO C. BENINE

A new shallow-bodied species of Moenkhausia is described from the upper Rio Negro, Amazon basin, Brazil. The new species is diagnosed from all congeners by the combination of a body depth not surpassing 33% in SL in adult specimens, seven scale rows between dorsal-fin origin and lateral line, five scale rows between pelvic-fin insertion and lateral line, a single conspicuous vertically elongated humeral blotch, and a conspicuous caudal peduncle blotch extending to the distal margin of the median caudal-fin rays. The new species was collected together with Jupiaba zonata, with which it shares a very similar color pattern. The similarity between these two taxa is interpreted as an additional case of Batesian mimicry between Moenkhausia and Jupiaba. 


Zootaxa ◽  
2019 ◽  
Vol 4712 (4) ◽  
pp. 561-575 ◽  
Author(s):  
WILLIAN M. OHARA ◽  
TULIO F. TEIXEIRA ◽  
JUAN G. ALBORNOZ-GARZÓN ◽  
J. MARCOS MIRANDE ◽  
FLÁVIO C. T. LIMA

A new species from rapids of Rio Aripuanã, Rio Madeira basin, in Brazil, and from the same type of habitat in the upper Rio Negro and upper Rio Orinoco basins in Brazil, Colombia, and Venezuela is described and assigned to the genus Hyphessobrycon. The new species presents an interrupted lateral line plus a single perforated scale on caudal peduncle and a small dark blotch on dorsal procurrent caudal-fin rays, features not found in the other species of Hyphessobrycon. Comments on the phylogenetic position of the new species, its rheophilic habits, and the biogeographic implications of its distribution are presented. 


Zootaxa ◽  
2020 ◽  
Vol 4852 (1) ◽  
pp. 1-40
Author(s):  
KLEBER MATHUBARA ◽  
MÔNICA TOLEDO-PIZA

Moenkhausia cotinho is redescribed based on the examination of meristic and morphometric data and external morphological characters of specimens from the Amazon and Orinoco basins and from rivers in the Guyana. The species is distinguished from congeners based on the combination of a reticulate color pattern, the presence of dark spots on the posterior edge of scales of the longitudinal rows dorsal to the lateral line, the presence of a dark blotch on the caudal-fin base failing to reach the posterior tip of the middle caudal-fin rays; the dorsal region of the eyes red to orange in life; 5/3 longitudinal series of scales, above and below the lateral line, respectively; and the tips of the pectoral-fin rays not extending beyond the base of the pelvic fin. All specimens of M. cotinho have a completely pored literal line except for a few specimens from drainages in the Guyana. The redefinition of the taxonomic limits and geographic distribution of M. cotinho allowed us to reevaluate the taxonomic limits and geographic distribution of Hemigrammus newboldi, the identity of which has been previously questioned, but which is clearly diagnosed from M. cotinho based on the relatively longer pectoral fin, the presence of conical teeth in the posterior portion of the dentary, the absence of a reticulate color pattern of body and in the shorter longitudinal dark stripe on body. In addition, two new species of Moenkhausia are described: Moenkhausia rondoni sp n. from the rio Madeira basin, Brazil and Moenkhausia pirahan sp n. from the lower rio Madeira and rio Trombetas and rio Tapajós basins, Brazil. 


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