FIGURE 24 in Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography

FIGURE 24. Holotype of Potamotrygon amazona, sp. nov. (MZUSP 117344, adult male, 532 mm DW, rio Jutaí, upper rio Amazonas basin, state of Amazonas, Brazil). A. Dorsal view. B. Ventral view

Taxonomic revision of the Potamotrygon scobina Garman, 1913 (Chondrichthyes: Myliobatiformes: Potamotrygonidae) complex, with biogeographical inferences

A família Potamotrygonidae constitui um grupo monofilético único dentre todos os elasmobrânquios por ser exclusivo de água doce e endêmico aos rios América do Sul. Apesar de seu monofiletismo, apresenta grandes problemas taxonômicos, uma vez que a grande variação nos padrões de coloração de disco e a ausência de um grande número de caracteres diagnósticos adequados proporcionam muitos erros e equívocos quanto a identificação de seus membros, principalmente pela presença de diversos padrões intermediários de coloração. Potamotrygon scobina Garman 1913, espécie cuja ampla distribuição e considerável variação morfológica geraram incertezas quanto a conspicuidade taxonômica do grupo, foi estudada morfologicamente de modo aprofundado, visando delimitar o status taxonômico dessa espécie e ajudar na resolução da problemática envolvida na taxonomia da família Potamotrygonidae. Espécimes cujas características pigmentares e corporais se assemelhavam à Potamotrygon scobina foram estudados e ao fim se obteve quatro novas espécies proximamente relacionadas à original. O refinamento das áreas de distribuição de cada uma das espécies, auxiliado da descrição taxonômica destas, auxiliaram na elaboração de uma hipótese de relacionamento entre estas espécies. Esta hipótese fora então comparada com dados geológicos da região amazônica e elaboraram-se inferências quanto à dinâmica biogeográfica tanto da família quanto das regiões amazônicas, sob um ponto de vista de um grupo de organismos nunca antes apresentadoThe family Potamotrygonidae constitutes a monophyletic group unique among all elasmobranch in being exclusive to freshwater and endemic to South America. Despite its supraspecific taxa monophyletic status, some major taxonomic problems exists, as many species present great variation in colour patterns; the absence of a large number of suitable diagnostic characters yield various errors and misconceptions regarding the identification of its members, mainly regarding the presence of several intermediate patterns of dorsal pigmentation. Potamotrygon scobina Garman 1913, a species whose wide distribution and morphological variation generated considerable uncertainties about its taxonomic conspicuity, was morphologically studied in depth in order to delimit its taxonomic status of this species and assist in the resolution of the problems involved in the taxonomy of the family Potamotrygonidae. Specimens whose pigmentary characteristics and body resembled that ofPotamotrygon scobina were studied and four new species closely related to P. scobina were discovered. The refinement of the areas of distribution of each species, and the taxonomic description of these, assisted in the development of a hypothesis of relationship between these species. This result was then compared with geological data of the Amazon region in order to draw inferences as to the dynamics of both the family and biogeographical regions of the Amazon, from a point of view of a group of organisms never before studied in this wa

Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae)

Fontenelle, João Pedro, Da Silva, João Paulo C. B., De Carvalho, Marcelo R. (2014): Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae). Zootaxa 3765 (3): 249-268, DOI: 10.11646/zootaxa.3765.3.

FIGURE 8 in Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae)

FIGURE 8. Ventral lateral-line canals of Potamotrygon limai, sp. nov. (based on MZUSP 104066). (A) Overall arrangement; (B) Detail of anterior disc region. Abbreviations: AJL: Anterior jugular loop; AST: Anterior sub pleural tubules; CON: Orbitonasal component of the supraorbital canal; HYC: Hyomandibular canal; IOC: Infraorbital canal; IOL: Infraorbital loop; JCH: Jugular component of the hyomandibular canal; JUG: Jugular canal; NAS: Nasal canal; NIL: Nasoinferior loop; PJL: Posterior jugular loop; PNC: Prenasal component of the nasal canal; PNL: Prenasal loop; SOC: Supraorbital canal; SOL: suborbital loop; SPC: subpleural component of the hyomandibular canal; SPL: subpleural loop.Published as part of Fontenelle, João Pedro, Da Silva, João Paulo C. B. & De Carvalho, Marcelo R., 2014, Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae), pp. 249-268 in Zootaxa 3765 (3) on page 259, DOI: 10.11646/zootaxa.3765.3.2, http://zenodo.org/record/25174

Biogeography of the neotropical freshwater stingrays (Myliobatiformes: Potamotrygoninae) reveals effects of continent‐scale paleogeographic change and drainage evolution

AimPaleogeographic changes have had profound effects on the evolution and diversity of the Neotropical biota. However, the influence of marine incursions on the origin, diversification, and distribution of fishes is still incompletely understood. We investigate the biogeographical and chronological patterns of diversification for the marine‐derived Neotropical freshwater stingrays (subfamily Potamotrygoninae) at a continental scale.LocationNeotropics, South America.TaxaNeotropical freshwater stingrays. Subfamily Potamotrygoninae (Myliobatiformes: Chondrichthyes).MethodsWe generated a time‐calibrated phylogeny for 35 of the 38 valid species of Neotropical freshwater stingrays, from most of the major river basins of South America, using four genes. We used BEAST2 to determine the chronology of population and species divergence events, and “BioGeoBEARS” to infer historical biogeographic patterns.ResultsThe Potamotrygoninae originated during the early/middle Miocene in the upper Amazon region. We recover clades associated with particular geographic areas and detect a recurrent pattern of upper Amazon clades sister to clades in adjacent basins. The timing of dispersals from the upper Amazon to adjacent areas corresponds with the end of the Pebas wetlands. Lower Amazon and Shield associated taxa are relatively young.Main conclusionsWe propose that the origin of the Neotropical freshwater stingrays is related to marine incursions that occurred during the Oligocene/Miocene. Subsequent diversification of Potamotrygoninae occurred in the Pebas wetland system in the upper Amazon with colonization of adjacent basins. These movements were generally unidirectional, with few lineages returning to the upper Amazon, and we speculate that ecological factors drove this pattern. We observed a burst of potamotrygonine diversification 5 Ma that appears to be related to the modern channelization of the Amazon Basin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167799/1/jbi14086-sup-0003-FigS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167799/2/jbi14086-sup-0001-FigS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167799/3/jbi14086_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167799/4/jbi14086-sup-0002-FigS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167799/5/jbi14086.pd

Rayas de agua dulce (Potamotrygonidae) de Suramérica. Parte II. Colombia, Brasil, Perú, Bolivia, Paraguay, Uruguay y Argentina

El libro es la continuación de una iniciativa de hace ya unos años (2012), donde varios países del área de distribución de la familia, decidieron unirse al ver como este recurso estaba disminuyendo o bien, era prácticamente desconocido. Este grupo tiene un gran impacto principalmente por su importancia como recurso pesquero ornamental, aunque también se usa como alimento, en la pesca deportiva y tiene incidencia en la salud pública. Para poder mitigar la posible sobreexplotación, surgió la necesidad de regular el comercio e intentar convertir la pesca ornamental de rayas en una actividad sostenible. Por ello, desde 2012 el IAvH junto a varios países propusieron la inclusión de varias especies al Apéndice III de Cites. Una de las limitantes de esta propuesta y por la cual no prosperó en su inicio, fue la falta de información sobre las especies.Bogotá, D. C