Papers by Oscar Akio Shibatta
Neotropical Ichthyology, 2005
A new pseudopimelodid catfish, Microglanis malabarbai, is described from the rio Ijuí drainage, t... more A new pseudopimelodid catfish, Microglanis malabarbai, is described from the rio Ijuí drainage, tributary of the middle rio Uruguay, Rio Grande do Sul, Brazil. The new species is distinguished from all other Microglanis species by the caudal fin color pattern, almost completely black, with a narrow vertical white band across central portions of the caudal-fin rays. Furthermore, it is distinguished from M. cottoides and M. eurystoma, both from rio Uruguay drainage, by head length, maxillary barbel length, internareal distance, and number of lateral-line pores, and from M. cibelae from the coastal drainages of northern Rio Grande do Sul and southern Santa Catarina states, by head length, maxillary barbel length, and body width. A key is presented for the species of Microglanis occurring in southern Brazil.
Neotropical Ichthyology, 2021
A new species of Rhyacoglanis is described from the rapids of Jatobal, Pará State, Brazil. This s... more A new species of Rhyacoglanis is described from the rapids of Jatobal, Pará State, Brazil. This species differs from the congeners by fusing hypurals 3, 4, and 5 (vs. hypural 5 free). It also differs from the other species, except for Rhyacoglanis epiblepsis, by the color pattern with numerous dark spots on the body, short post-cleithral process, rounded pectoral and caudal fins, and incomplete lateral line. This species is known only from the type locality, which is currently flooded by the Tucuruí reservoir.
Check List, 2015
Fishes were collected at 36 sites in first order streams of Tibagi River basin, Paraná state, Bra... more Fishes were collected at 36 sites in first order streams of Tibagi River basin, Paraná state, Brazil. A total of 2,669 individuals belonging to 47 species of 13 families and six orders were collected. The number of collected species represented 95.9% of the expected number of species for the studied area as estimated by Chao 1, and 93.4% by ACE, indicating an effective sampling. The highest richness was recorded in the tributaries at the lower region (Zone III) of the Tibagi River basin, with 33 species, including 16 species not found in the other regions of the basin. In the streams of the middle and upper regions (Zones II and I) each presented less richness, with 10 (two exclusive) and 25 (11 exclusive) species, respectively. This study shows a high geographic variation in the composition of fish fauna among zones, maybe related to historical and/or ecological influences.
Aquatic Invasions, 2020
The Upper Paraná River Basin (UPRB) is harmed by several human activities, among which species in... more The Upper Paraná River Basin (UPRB) is harmed by several human activities, among which species introduction is particularly intense, making it the Neotropical ecoregion with the highest number of non-native fish species. Leporinus tigrinus Borodin, 1929 is a native species of the Tocantins-Araguaia River Basin and was recorded for the first time in the UPRB in 1999. Since then, the species was progressively recorded in lower portions of the UPRB (downstream Corumbá River). Therefore, the aim of this study was to provide evidence of possible introduction, establishment and dispersion of the species in that region. For this purpose, an inventory of its occurrence was performed by sampling ichthyoplankton, juveniles and adults of fishes in tributaries of the Porto Primavera Reservoir, as well as by compiling data from scientific collections considering all the UPRB. Diet and reproductive aspects were also analyzed. Overall, 23 specimens of L. tigrinus (10 adults and 13 juveniles) and five eggs (identified by DNA Barcoding) were sampled, evidencing the occurrence, reproduction, and recruitment of this species in the basin. The results of this study support the conclusion that L. tigrinus is an introduced species in the lower portion of the UPRB, capable of dispersing over long distances by passing through several reservoirs and dams (from upstream to downstream), possibly via turbines, spillways, locks, and fishways. Its dispersal pathway differs from the patterns observed for most invasive fish species in this basin, and suggests a substantial downstream dispersion through dams, even in the absence of fishways.
Neotropical Ichthyology, 2016
The species Rhamdia branneri Haseman, 1911 and the subspecies Rhamdia branneri voulezi Haseman, 1... more The species Rhamdia branneri Haseman, 1911 and the subspecies Rhamdia branneri voulezi Haseman, 1911 from rio Iguaçu are currently recognized as synonyms of Rhamdia quelen (Quoy & Gaimard, 1824). However, recent karyotype and ecomorphology studies distinguish R. branneri and R. voulezi as different species. Examination of Rhamdia populations from rio Iguaçu, including type specimens, together with other congeners from rio Tibagi, allowed to properly reexamine the situation of these Haseman's taxa and references given to Rhamdia in the Iguaçu. The species R. branneri and R. voulezi have strong serrae with large basis on both margins of the pectoral-fin spine, uncommon in the remaining species of Rhamdia and different from the fine serrate margins of the pectoral spine of R. quelen ; a regular dorsal profile, slightly curved between supraoccipital and dorsal fin; with dorsal dark-brown or light-gray coloration along body, abdomen pale, without profuse small black spots, common in ...
... À Angela Maria Veregue, Alda Maria Borgui e Ana Karina Varoni pela coleta de dados das gônada... more ... À Angela Maria Veregue, Alda Maria Borgui e Ana Karina Varoni pela coleta de dados das gônadas dos peixes estudados. À Claudia Bueno dos Reis Mattinez pela ajuda e comentários deste manuscrito. Finalmente, à Priscila Lazoski pela confecção das figuras. Revta bras. ...
... ou a população revelam em seu crescimento as condições ambientais, bióticas e abióticas vigen... more ... ou a população revelam em seu crescimento as condições ambientais, bióticas e abióticas vigentes (BENEDITO-CECÍLIO & AGOSTINHO 1997 ... Escamas com até oito anéis foram encontradas, para ambos os sexos, com uma única exceção, onde uma fêmea apresentou nove ...
PMENT OF FlSII SPECIES FROM TIBAG I RIVER. The tish assemblage in a stretch ofTibagi ri ver was s... more PMENT OF FlSII SPECIES FROM TIBAG I RIVER. The tish assemblage in a stretch ofTibagi ri ver was studied during the period of one year, throught monthly sampling. lt was observed lhat four fi sh species (Sehizodoll inlel'lIIedius Garavello & Britski, 1990, Aeeslrorhynehus laellslris Reinhardt, 1874, Pimelodus maeulalus Lacépede, 1803 and SIeindacl1l1erina inseulpla Fernandez-Yepez, 1948) were very tI'equent and they represenl ali lhe main trophic groups. ln order to characterize feeding activity, tàt storage and reproduction the l11eans degree of repletion, fat and maturation, obtained for each species in each month were compared among the four fish species. SIeinda-c1merina insculpla, a detritivovous species was the one wi th the highest teeding activity while A. lacuslris, a piscivorous fish, showed the lowest feeding ac tivity. For these two species it was clearly observed a sequence of events: higher feeding activity tollowed by higher tàt stOl'age followed by reproduction, that was not observed tor P. maculalus and S. inlermedius. The variations in leeding acti vity and fat stOl'age showed by P. maculalus and S. inlermedius might be related to their diets.
A synthesis concerning fishes from Upper Paraná River basin is presented, based on data from fish... more A synthesis concerning fishes from Upper Paraná River basin is presented, based on data from fish-collections, literature, and new field samples. Three hundred and ten species, pertaining to 11 orders and 38 families, are referred to the drainage, elevating anterior estimates. Concerning total species, 236 (76.1%) are autochthonous, 67 (21.6%) are allochthonous, and seven (2.3%) are exotic. Principal causes of occurrence of non-native species are: a) dispersal from the Lower Paraná, after the construction of Itaipu dam, and b) escapes from aquaculture farms. Most species (65%) are small-sized, having less than 21 cm of length, and the great majority occurs only in headwaters and small streams. One of the best known and most studied in Brazil, Upper Paraná ichthyofauna richness is far from reaching actual numbers, considering the exponential elevation of species presented herein. Indeed, in the last years various new species have been described and around 50 other species, already recognized as new, are now under description. The improvement on the knowledge about Upper Paraná ichthyofauna is proportional to the number of researchers involved with studies in the area and, unequivocally, reflects recent initiatives stimulating and incrementing taxonomic research, and also improving access to fish collections and to poor or never-sampled areas. However, if we are going to maintain the number of species descriptions per year of last decade, the 50 new species already recognized, will be described only in the next ten years, a period too long. In consequence it is very important that scientific community and grant agencies find and offer initiatives in order to elevate the number of new taxa descriptions per year.
The reef species Abudefduf saxatilis (Linnaeus, 1758) is usually considered as a single large Wes... more The reef species Abudefduf saxatilis (Linnaeus, 1758) is usually considered as a single large Western Atlantic population distributed in reef habitats from northern United States (Rhode Island) to Uruguay. However, principal components and canonical variables analyses of samples distributed along the Brazilian coast (Rio Grande do Norte, Ceará, Bahia, Rio de Janeiro and Santa Catarina states), and oceanic islands of Atol das Rocas and St. Paul's Rocks, showed morphological variation, which could suggest subdivisions among different populations. Clinal variations of meristic traits along the northsouth direction seem to have temperature as their main causative factor. Also, there was a greater similarity among contiguous populations that become more differentiated with distance. In this context, the Brazilian Current flowing, in north-south direction, seems to play an important dispersive role. There were differences between insular and continental populations, which suggest the occurrence of selfrecruitment either by a possible existence of circular currents, an active larval role and/or a possible selection for an optimal egg-laying period leading to restrictions in their dispersion. Thus, phenetic divergences seem to suggest restrictions to the genetic flow in the South Atlantic A. saxatilis population.
Iheringia Serie Zoologia, 2005
Fish diversity in the UHE Escola Engenharia Mackenzie (Capivara) reservoir, Paranapanema River, u... more Fish diversity in the UHE Escola Engenharia Mackenzie (Capivara) reservoir, Paranapanema River, upper Rio Paraná basin, Brazil, and the importance of large tributaries in its maitenance. Fish samples were taken in four stretches along a gradient formed by the UHE Escola Engenharia Mackenzie (Capivara) reservoir. The diversity of species was analyzed by the constance, index of Shannon-Wiener and similarity of the composition among stretches through the Jaccard's coefficient. The reservoir presents a richness of fishes composed by 67 species distributed in 5 orders; 47% of the species are constant, 15% are accessory and 28% are accidental. The highest values of Shannon-Wiener diversity and Jaccard's similarity were obtained in Cinzas and Tibagi, wich are the most distant points from the dam and which present large tributaries. The lowest values were found in Cruzália and Porecatu, which respectively correspond to the stretches with lotic and semi-lotic environmental characteristics. This work demonstrates the extreme importance of tributaries for the maintenance of species diversity in a reservoir, as a result of the preservation of the original characteristics of lotic systems in those river stretches and consequent reduction of the damming impact.
Biota Neotropica, 2007
To evaluate the environmental quality and patterns of diversity of fish species from an altered u... more To evaluate the environmental quality and patterns of diversity of fish species from an altered urban stream, we analyzed habitat quality, water velocity and fish species distribution. In order to include a larger amount of environments and considering the distinct physical characteristics and human influence, five stream sites were seasonally sampled. A total of 5,426 individuals, being 12 species and 6 orders, were collected. The degree of environmental alteration at each sampling site was determined through the analysis of habitat diversity and water velocity. The intermediate sites showed higher species richness as the upper sites were the most altered ones. The lower sites showed adverse physical characteristics to the permanence of some species. These results indicated that hydrological and geomorphological characteristics should influence the aquatic biota richness. Nonetheless, it was found that native species still find favorable places to their development, even with exoti...
Revista Brasileira De Zoologia, 2003
Biota Neotropica, 2007
A synthesis concerning fishes from Upper Paraná River basin is presented, based on data from fish... more A synthesis concerning fishes from Upper Paraná River basin is presented, based on data from fish-collections, literature, and new field samples. Three hundred and ten species, pertaining to 11 orders and 38 families, are referred to the drainage, elevating anterior estimates. Concerning total species, 236 (76.1%) are autochthonous, 67 (21.6%) are allochthonous, and seven (2.3%) are exotic. Principal causes of occurrence of non-native species are: a) dispersal from the Lower Paraná, after the construction of Itaipu dam, and b) escapes from aquaculture farms. Most species (65%) are small-sized, having less than 21 cm of length, and the great majority occurs only in headwaters and small streams. One of the best known and most studied in Brazil, Upper Paraná ichthyofauna richness is far from reaching actual numbers, considering the exponential elevation of species presented herein. Indeed, in the last years various new species have been described and around 50 other species, already re...
Neotropical Ichthyology, 2008
Microglanis carlae, new species, is described from the río Paraguay basin and distinguished from ... more Microglanis carlae, new species, is described from the río Paraguay basin and distinguished from its congeners by the following combination of characters: paired and anal fins mottled or with thin faint bands, trunk with dark-brown saddles, anterior margin of pectoral spine with serrations retrorse proximally and antrorse distally, tip of pectoral spine as a distinct bony point, continuous portion of lateral line reaching vertical through last dorsal-fin ray, caudal peduncle with irregularly shaped, faint to dark blotch, maxillary barbel surpassing vertical through dorsal-spine origin, and dark bar on posterior flank continuous from base of adipose fin to that of anal fin. The new species is included in the Microglanis parahybae species complex on the basis of color pattern. Microglanis carlae, espécie nova, é descrita da bacia do rio Paraguai e distinguida de todas as congêneres pela seguinte combinação de caracteres: nadadeira anal e nadadeiras pares pigmentadas ou com faixas estreitas, corpo com manchas ou faixas escuras, margem anterior do espinho peitoral com serras retrorsas proximalmente e antrorsas distalmente, espinho peitoral terminando numa ponta, parte contínua da linha lateral atingindo a vertical que passa pelo último raio da nadadeira dorsal, pedúnculo caudal com uma mancha tênue a escura de forma irregular, barbilhão maxilar ultrapassando a vertical que passa pela origem do espinho da nadadeira dorsal, e uma barra escura contínua da base da nadadeira adiposa até a anal. A nova espécie é incluída no complexo de espécies Microglanis parahybae com base no padrão de colorido.
… : Ciências Biológicas e …, 2010
Trichogaster leeri é considerado um peixe pacífico e muito utilizado em aquarismo pela beleza de ... more Trichogaster leeri é considerado um peixe pacífico e muito utilizado em aquarismo pela beleza de suas cores. O presente estudo teve como objetivos avaliar a ocupação da coluna da água por machos adultos quando mantidos com outros machos da mesma espécie. Foram utilizados três aquários com as dimensões de 35 cm de comprimento, 22 cm de altura e 16 cm de largura, com substrato de cascalho e vegetação artificial. O vidro frontal foi dividido em 12 quadrantes, ordenados da esquerda para a direita e de cima para baixo. Três exemplares de aproximadamente 8 cm de comprimento total foram utilizados para observação das freqüências de ocorrência nos quadrantes, nas seguintes situações: isolados, agrupados em duplas e os três juntos. Os dados foram analisados pelo teste χ 2, ao nível de significância de 5%. Foi observado que, quando associados em um mesmo aquário, os indivíduos ocupam uma determinada posição na coluna da água. Isso significa que, apesar do comportamento aparentemente pacífico, os machos se evitam ocupando distintas posições espaciais.
… Biológicas e da …, 2009
Biologia Animal e Vegetal, PR Recebido para a publicação em 31/10/05 Aceito para a publicação em ... more Biologia Animal e Vegetal, PR Recebido para a publicação em 31/10/05 Aceito para a publicação em 17/02/2006 RESUMO O estudo da comunidade de peixes juvenis em uma lagoa marginal do Rio Imbituva foi realizado em um trecho próximo à foz (25°07'13''S e 50°23'20''W), no período de abril a maio de 2005, por meio de duas coletas realizadas com peneirões utilizados na vegetação aquática e rede de arrasto em áreas limpas. Foram capturados 533 exemplares de peixes distribuídos em 7 espécies, pertencentes a 6 gêneros, 4 famílias e 2 ordens. Characiformes foi a ordem mais abundante, com maior número de representantes pertencentes à família Characidae. A espécie mais freqüente foi o lambari-prata Hyphessobrycon reticulatus, com 404 indivíduos. A espécie Mimagoniates microlepis foi encontrada pela primeira vez na bacia do rio Tibagi.
Neotropical Ichthyology, 2005
Microglanis garavelloi, new species, collected in tributaries of rio Paranapanema and rio Tietê, ... more Microglanis garavelloi, new species, collected in tributaries of rio Paranapanema and rio Tietê, is the first species of the genus described from upper rio Paraná basin. The new species can be distinguished from other species of Microglanis on morphometric characters, color pattern, caudal-fin shape, pectoral-spine morphology and lateral line development. Characters used specifically to distinguish M. garavelloi from M. cottoides (laguna dos Patos and rio Uruguay basins) and M. parahybae (rio Paraíba do Sul basin) include morphometrics, color pattern and pectoral-spine serration. Microglanis garavelloi, espécie nova, coletado em tributários do rio Paranapanema e rio Tietê, é a primeira espécie do gênero descrita da bacia do alto rio Paraná. A nova espécie pode ser distinguida das outras espécies de Microglanis com base em caracteres morfométricos, padrão de colorido, forma da nadadeira caudal, morfologia do espinho da nadadeira peitoral e desenvolvimento da linha lateral. Caracteres utilizados para distinguir M. garavelloi de M. cottoides (bacias da laguna dos Patos e rio Uruguai) e M. parahybae (bacia do rio Paraíba do Sul) incluem a morfometria, o padrão de colorido e as serras do espinho da nadadeira peitoral.
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Papers by Oscar Akio Shibatta