scholarly journals A new species of Moenkhausia (Characiformes: Characidae) from the rio Madeira basin, Brazil, with comments on the evolution and development of the trunk lateral line system in characids

2021 ◽  
Vol 19 (2) ◽  
Author(s):  
Manoela Maria Ferreira Marinho ◽  
Willian Massaharu Ohara ◽  
Fernando Cesar Paiva Dagosta

Abstract A new species of Moenkhausia is described from the rio Machado drainage, Amazon basin, Brazil. It is diagnosed from congeners by its color pattern, consisting of the concentration of chromatophores on the anterior portion of body scales, the horizontally elongate blotch on caudal peduncle, a bright golden coloration of the dorsal portion of eye when alive, and a dark line crossing the eye horizontally. The new species has variable morphology regarding trunk lateral-line canals. Most fully grown individuals do not have enclosed bony tube in many lateral line scales, resembling early developmental stages of tube formation of other species. This paedomorphic condition is interpreted as a result of developmental truncation. Such evolutionary process may have been responsible for the presence of distinct levels of trunk lateral line reductions in small characids. Variation in this feature is common, even between the sides of the same individual. We reassert that the degree of trunk lateral-line tube development must be used with care in taxonomic and phylogenetic studies, because reductions in the laterosensory system may constitute parallel loss in the Characidae. We suggest the new species to be categorized Near Threatened due to the restricted geographical distribution and continuing decline in habitat quality.

Zootaxa ◽  
2017 ◽  
Vol 4353 (1) ◽  
pp. 89
Author(s):  
HRISHIKESH CHOUDHURY ◽  
D. KHLUR B. MUKHIM ◽  
SUDEM BASUMATARY ◽  
DEISAKEE P. WARBAH ◽  
DANDADHAR SARMA

Schistura larketensis, a new species of cavernicolous loach, is described from Khung, a limestone cave in Meghalaya, India. The species differs from Schistura papulifera, its only troglomorphic congener from northeast India, in having a smooth ventral surface of the head, the presence of a small cylindrical axillary pelvic lobe, and the presence of three pores in the supratemporal canal of the cephalic lateral-line system. Apart from these differences, the species can be immediately distinguished from all other species of Schistura from the Brahmaputra River and neighboring basins by the complete absence (or only vestigial presence) of eyes. 


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Rafaela Priscila Ota ◽  
Valéria Nogueira Machado ◽  
Marcelo C. Andrade ◽  
Rupert A. Collins ◽  
Izeni Pires Farias ◽  
...  

ABSTRACT Pacus of the genus Myloplus represent a formidable taxonomic challenge, and particularly so for the case of M. asterias and M. rubripinnis, two widespread and common species that harbor considerable morphological diversity. Here we apply DNA barcoding and multiple species discovery methods to find candidate species in this complex group. We report on one well-supported lineage that is also morphologically and ecologically distinct. This lineage represents a new species that can be distinguished from congeners by the presence of dark chromatophores on lateral-line scales, which gives the appearance of a black lateral line. It can be further diagnosed by having 25-29 branched dorsal-fin rays (vs. 18-24), 89-114 perforated scales from the supracleithrum to the end of hypural plate (vs. 56-89), and 98-120 total lateral line scales (vs. 59-97). The new species is widely distributed in the Amazon basin, but seems to have a preference for black- and clearwater habitats. This ecological preference and black lateral line color pattern bears a striking similarity to the recently described silver dollar Metynnis melanogrammus.


2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Isabel M. Soares ◽  
Vinicius A. Bertaco ◽  
Priscila Madoka M. Ito ◽  
Jansen Zuanon

ABSTRACT A new species of Boehlkea is described from rio Japurá, Amazon basin. The new species differs from B. fredcochui by the presence of a vertically elongate humeral spot (vs. absence), complete lateral line (vs. incomplete), four rows of scales below lateral line (vs. three), and lower number of branched anal-fin rays (17-21 vs. 22-25), and from B. orcesi by the higher number of maxillary teeth (13-14 vs. 5-12), greater head length (27.9-29.9% vs. 24.3-27.5% of SL), and by the color pattern (basal half of dorsal-fin, distal portion of pelvic-fin, lower caudal-fin lobe and anal-fin with black chromatophores vs. absence of black chromatophores in the fins).


Zootaxa ◽  
2019 ◽  
Vol 4603 (1) ◽  
pp. 183
Author(s):  
HERALDO A. BRITSKI ◽  
JOSÉ L. BIRINDELLI

A new species of Leporinus is described from the rio Teles Pires, rio Tapajós basin, Amazon basin, Brazil. The new species is diagnosed based on dental formula 3/4, a dark midlateral stripe on body and a series of transversal dark bars on the dorsum. The new species is similar to a handful of congeners based on the color pattern, including L. britski, L. microphysus, L. parvulus, and L. vanzoi, all of which also occur at the rio Tapajós basin. The new species is distinguished from the aforementioned congeners based on number of premaxillary teeth, number of scales in lateral line and/or around caudal peduncle. The new species is apparently endemic to the rio Teles Pires near the Sete Quedas rapids and upstream.


Zootaxa ◽  
2010 ◽  
Vol 2632 (1) ◽  
pp. 53 ◽  
Author(s):  
WILLIAM BENEDITO GOTTO RUIZ ◽  
OSCAR AKIO SHIBATTA

Microglanis robustus, new species, is the first Microglanis to be described from the Rio Tocantins basin, Pará, Brazil, and differs from the congeners by the presence of a cordiform blotch in the nape, instead of a transverse light stripe; neuromasts of the superficial lines surrounded by melanophores; robust body with short snout, head and predorsal distance; and deep caudal peduncle. The mapping of superficial neuromasts and cephalic sensory canals evidenced intra and interespecific polymorphisms and, therefore, of little value for phylogenetic analysis within the genus.


Zootaxa ◽  
2007 ◽  
Vol 1393 (1) ◽  
pp. 35 ◽  
Author(s):  
MAURICE KOTTELAT ◽  
DANIEL R. HARRIES ◽  
GRAHAM S. PROUDLOVE

Schistura papulifera, new species, is described from a cave of the Synrang Pamiang system, Meghalaya State, India. It is distinguished from all other known species of Schistura in having the lower half of the head covered by small skin projections and 5 pores in the supratemporal canal of the cephalic lateral-line system. In addition, it has a white body and vestigial eyes. The closest epigean relative of S. papulifera has not yet been identified due to the lack of survey and usable data. The identity of the cave nemacheiline from Siju Cave is briefly discussed, but this remains inconclusive, again due to the lack of material and usable data.


Zootaxa ◽  
2007 ◽  
Vol 1393 (1) ◽  
pp. 35-44 ◽  
Author(s):  
MAURICE KOTTELAT ◽  
DANIEL R. HARRIES ◽  
GRAHAM S. PROUDLOVE

Schistura papulifera, new species, is described from a cave of the Synrang Pamiang system, Meghalaya State, India. It is distinguished from all other known species of Schistura in having the lower half of the head covered by small skin projections and 5 pores in the supratemporal canal of the cephalic lateral-line system. In addition, it has a white body and vestigial eyes. The closest epigean relative of S. papulifera has not yet been identified due to the lack of survey and usable data. The identity of the cave nemacheiline from Siju Cave is briefly discussed, but this remains inconclusive, again due to the lack of material and usable data.


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 ◽  
2011 ◽  
Vol 2827 (1) ◽  
pp. 1 ◽  
Author(s):  
MARCELO R. DE CARVALHO ◽  
MARK H. SABAJ PEREZ ◽  
NATHAN R. LOVEJOY

A new species of Neotropical freshwater stingray, family Potamotrygonidae, is described from the Río Nanay in the upper Río Amazonas basin of Peru. Potamotrygon tigrina, n. sp., is easily distinguished from all congeners by its conspicuous dorsal disc coloration, composed of bright yellow to orange vermiculations strongly interwoven with a dark-brown to deep-black background. Additional features that in combination diagnose P. tigrina, n. sp., include the presence of a single angular cartilage, low and not closely grouped dorsal tail spines, and coloration of tail composed of relatively wide and alternating bands of creamy white and dark brown to black. Potamotrygon tigrina is closely related to Potamotrygon schroederi Fernandez-Yépez, 1958, which occurs in the Rio Negro (Brazil) and Río Orinoco (Venezuela, Colombia). Both species are very similar in proportions and counts, and share features hypothesized to be derived within Potamotrygonidae, related to their specific angular cartilage morphology, distal tail color, dorsal tail-spine pattern, and ventral lateral-line system. To further substantiate the description of P. tigrina, n. sp., we provide a redescription of P. schroederi based on material from the Rio Negro (Brazil) and Río Orinoco (Venezuela). Specimens from the two basins differ in number of vertebral centra and slightly in size and frequency of rosettes on dorsal disc, distinctions that presently do not warrant their specific separation. Potamotrygon tigrina is frequently commercialized in the international aquarium trade but virtually nothing is known of its biology or conservation status.


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