On Eryphus Perty, 1832 (Dichophyiini), Eriphus Audinet-Serville, 1834 (Trachyderini, Trachyderina), and Eryphus Klug, 1829, with description of a new genus, and corrections on publication dates (Coleoptera, Cerambycidae)

The validity of two forgotten names, EryphusKlug, 1829 and E. rubricollisKlug, 1829, is discussed. The former is considered a nomen oblitum and synonymized with EriphusAudinet-Serville, 1834, a nomen protectum; the latter is revalidated and Eriphus purpuratus Chevrolat, 1862 is considered a junior synonym of Eriphus rubricollis (Klug, 1829). A lectotype is designated to Eryphus rubricollisKlug, 1829. The date of the work where EriphusAudinet-Serville, 1834 was described is corrected. A new genus is described in Dichophyiini Gistel, 1848 to include the species currently allocated in Eryphus sensuNapp & Martins (2002). The dates of publication of genera and species described by Fairmaire & Germain (Révision des Coléoptères du Chili (suite)) are corrected.(AU)

A new synonymy in Anisopodus White (Coleoptera, Cerambycidae, Lamiinae, Acanthocinini)

Anisopodus subarmatus Melzer, 1931 is synonymized with A. jaculus (Gyllenhal, 1817) and a discussion about the type-locality of the latter is provided. Photographs of the lectotype of the former and of the holotype of the latter are provided.(AU)

Phyllanthus chacoensis (Phyllanthaceae): new record for the Brazilian Amazon and its lectotypification / Phyllanthus chacoensis (Phyllanthaceae): novo registro para a Amazônia brasileira e sua lectotipificação

The first record of Phyllanthus chacoensis for the Brazilian Amazon is presented, based on a specimen from Rondônia state. The species can be recognized by its cauliflorous inflorescence, staminate and pistillate flowers with 4 sepals, devoid of a floral disk, 4 stamens, 2-carpellary ovary, drupaceous, ellipsoidal fruits, with one seed per locule. The species was previously known only from the central-western and northeastern regions of the Caatinga and Pantanal domains in Brazil. We provide a list of synonyms, a detailed description, an updated geographic distribution map in Brazil, data on habitat and conservation status, illustrations of its reproductive characters, and detailed photographs. We also propose a lectotype for the species.(AU)

Apresentamos o primeiro registro de Phyllanthus chacoensis para a Amazônia brasileira, baseado em um espécime encontrado em Rondônia. A espécie pode ser reconhecida pela inflorescência cauliflora, flores de ambos os sexos com 4 sépalas, desprovidas de disco floral, 4 estames, ovário 2-carpelar e frutos elipsoides, drupáceos, com uma semente por lóculo. No Brasil, a espécie era referida, até o momento, apenas para as regiões Centro-Oeste e Nordeste nos domínios Caatinga e Pantanal. Apresentamos a lista de sinônimos, descrição morfológica detalhada, um mapa atualizado da distribuição geográfica no Brasil, dados sobre habitat e status de conservação, assim como fotos em campo e ilustração dos caracteres reprodutivos. Adicionalmente, propomos um lectótipo para o nome.(AU)

The species of the bee genus Centris Fabricius, 1804 described by Curt Schrottky (Hymenoptera: Apidae)

Abstract In this paper the primary types of Centris bees described by the German entomologist Curt Schrottky were studied. The type specimens of C. anisitsi, C. brethesi, C. ehrhardti, C. garleppi, C. garleppi var. unifasciata, C. pectoralis var. flava, C. pocograndensis, and C. xanthocnemis var. perflava were analyzed, providing notes on their current status and depository. To stabilize the application of the name C. ehrhardti a lectotype was designated. Notes and photographs of selected types are also provided.

A contribution to the genera Plectonotum Gorham and Hyponotum Wittmer, with the description of sixteen new species from Peru (Coleoptera, Cantharidae)

Abstract Sixteen species of Peruvian Dysmorphocerinae (Cantharidae) are described as new (regions in parenthesis): Hyponotum macrocephalum sp. nov. (Huanuco); H. succhabamba sp. nov. (Cajamarca); Plectonotum altomayo sp. nov. (Amazonas); P. amazonas sp. nov. (Amazonas); P. bicoloricolle sp. nov. (Huanuco); P. carpish sp. nov. (Huanuco); P. celendin sp. nov. (Cajamarca); P. costae sp. nov. (Cajamarca); P. huariaca sp. nov. (Pasco and Huanuco); P. huascaran sp. nov. (Ancash); P. huertoae sp. nov. (Cajamarca); P. leymebamba sp. nov. (Amazonas); P. luteipes sp. nov. (Amazonas); P. oxapampa sp. nov. (Pasco); P. rubrithorax sp. nov. (Huanuco); P. shipasbamba sp. nov. (Amazonas). A lectotype is designated for Plectonotum longissimum (Pic, 1927) for which a redescription is provided. Plectonotum ruficolleWittmer, 1988, homonym of Plectonotum ruficollePic, 1926, is renamed as Plectonotum neoruficolle nom. nov. New keys are proposed in English and Spanish for the identification of the Peruvian species of the genus Plectonotum and the South American species of the genus Hyponotum Wittmer, together with macrophotographs of habitus, details of pronotum, male genitalia and a cartographic representation of their distribution.

The species of the bee genus Centris Fabricius, 1804 described by Curt Schrottky (Hymenoptera: Apidae)

In this paper the primary types of Centris bees described by the German entomologist Curt Schrottky were studied. The type specimens of C. anisitsi, C. brethesi, C. ehrhardti, C. garleppi, C. garleppi var. unifasciata, C. pectoralis var. flava, C. pocograndensis, and C. xanthocnemis var. perflava were analyzed, providing notes on their current status and depository. To stabilize the application of the name C. ehrhardti a lectotype was designated. Notes and photographs of selected types are also provided.

A contribution to the genera Plectonotum Gorham and Hyponotum Wittmer, with the description of sixteen new species from Peru (Coleoptera, Cantharidae)

Sixteen species of Peruvian Dysmorphocerinae (Cantharidae) are described as new (regions in parenthesis): Hyponotum macrocephalum sp. nov. (Huanuco); H. succhabamba sp. nov. (Cajamarca); Plectonotum altomayo sp. nov. (Amazonas); P. amazonas sp. nov. (Amazonas); P. bicoloricolle sp. nov. (Huanuco); P. carpish sp. nov. (Huanuco); P. celendin sp. nov. (Cajamarca); P. costae sp. nov. (Cajamarca); P. huariaca sp. nov. (Pasco and Huanuco); P. huascaran sp. nov. (Ancash); P. huertoae sp. nov. (Cajamarca); P. leymebamba sp. nov. (Amazonas); P. luteipes sp. nov. (Amazonas); P. oxapampa sp. nov. (Pasco); P. rubrithorax sp. nov. (Huanuco); P. shipasbamba sp. nov. (Amazonas). A lectotype is designated for Plectonotum longissimum (Pic, 1927) for which a redescription is provided. Plectonotum ruficolleWittmer, 1988, homonym of Plectonotum ruficollePic, 1926, is renamed as Plectonotum neoruficolle nom. nov. New keys are proposed in English and Spanish for the identification of the Peruvian species of the genus Plectonotum and the South American species of the genus Hyponotum Wittmer, together with macrophotographs of habitus, details of pronotum, male genitalia and a cartographic representation of their distribution.

Redescription of Ancistrus greeni (Siluriformes: Loricariidae), and description of a new species from the río Madre de Dios basin, Peru

A new species of Ancistrus is described from minor tributaries of the río Madre de Dios basin (Cusco - Madre de Dios - Puno), in Peru. The new species shares with A. greeni an uncommon unicusp dentition; but it is distinguished from A. greeni by a larger orbital diameter, deeper caudal peduncle, and larger adipose-fin spine. The redescription of A. greeni is provided, and its recognition along with the discovery of this new species increases to five the officially number of Ancistrus species from the río Madre de Dios basin. The lectotype and paralectotype of A. greeni are provided.(AU)

Uma nova espécie de Ancistrus é descrita de pequenos tributários da bacia do rio Madre de Dios (Cusco - Madre de Dios - Puno), no Peru. A nova espécie compartilha com A. greeni uma dentição unicuspidada pouco comum e é diagnosticada de A. greeni pelo maior diâmetro orbital, maior altura do pedúnculo caudal e maior espinho da nadadeira adiposa. A redescrição de A. greeni é fornecida, e seu reconhecimento juntamente com a descoberta dessa nova espécie incrementam para cinco o número oficial de Ancistrus registradas para a bacia do rio Madre de Dios. O lectótipo e paralectótipo de A. greeni são fornecidos.(AU)

Redescription of Ancistrus greeni (Siluriformes: Loricariidae), and description of a new species from the río Madre de Dios basin, Peru

A new species of Ancistrus is described from minor tributaries of the río Madre de Dios basin (Cusco - Madre de Dios - Puno), in Peru. The new species shares with A. greeni an uncommon unicusp dentition; but it is distinguished from A. greeni by a larger orbital diameter, deeper caudal peduncle, and larger adipose-fin spine. The redescription of A. greeni is provided, and its recognition along with the discovery of this new species increases to five the officially number of Ancistrus species from the río Madre de Dios basin. The lectotype and paralectotype of A. greeni are provided.(AU)

Uma nova espécie de Ancistrus é descrita de pequenos tributários da bacia do rio Madre de Dios (Cusco - Madre de Dios - Puno), no Peru. A nova espécie compartilha com A. greeni uma dentição unicuspidada pouco comum e é diagnosticada de A. greeni pelo maior diâmetro orbital, maior altura do pedúnculo caudal e maior espinho da nadadeira adiposa. A redescrição de A. greeni é fornecida, e seu reconhecimento juntamente com a descoberta dessa nova espécie incrementam para cinco o número oficial de Ancistrus registradas para a bacia do rio Madre de Dios. O lectótipo e paralectótipo de A. greeni são fornecidos.(AU)

Systematic revision of the Neotropical catfish genus Scleronema (Siluriformes: Trichomycteridae), with descriptions of six new species from Pampa grasslands

ABSTRACT The Neotropical genus Scleronema is revised based on the re-examination of the type specimens and 1,713 newly collected specimens. Scleronema is diagnosed from other trichomycterids by the following unambiguous derived characters: fleshy flap at the base of the maxillary barbell; skin flap in the posterior margin of the opercle; articulation between the autopalatine and the vomer ventrally located, with the medial margins of the autopalatines very close to each other; and autopalatine with an interrupted or not interrupted ossified arch-shaped process on its dorsal surface forming a canal. Scleronema minutum and S. operculatum are redescribed, S. angustirostre is considered a junior synonym of S. minutum, and six new species are described. A lectotype is designated for Trichomycterus minutus. The type localities of S. angustirostre, S. minutum, and S. operculatum are reviewed in order to correct erroneous information cited in articles and catalogs subsequent to the original descriptions. Species of Scleronema are geographically distributed in the La Plata basin and Atlantic coastal drainages from Southern Brazil, Southern Paraguay, Northeastern Argentina and Uruguay. They inhabit rivers or streams with sand- or gravel-bottoms across the Pampa grasslands. We provide evidences to recognize two putative monophyletic units within the genus, namely the S. minutum species group and the S. operculatum species group, and discuss the distribution patterns of their species.

RESUMO O gênero Neotropical Scleronema é revisado com base na análise do material-tipo e outros 1.713 espécimes recentemente coletados. Scleronema é diagnosticado de outros tricomicterídeos pelos seguintes caracteres derivados não ambíguos: aba de pele na base do barbilhão maxilar; aba de pele na margem posterior do opérculo; articulação entre o autopalatino e o vômer posicionada ventralmente, deixando as margens mediais dos autopalatinos muito próximas entre si; e o autopalatino com um processo com formato de arco na sua superfície dorsal. Scleronema minutum e S. operculatum são redescritas, S. angustirostre é considerada um sinônimo júnior de S. minutum e seis novas espécies são descritas. Um lectótipo é designado para S. minutum. As localidades-tipo de S. angustirostre, S. minutum e S. operculatum são revisadas com o intuito de corrigir informações errôneas citadas em artigos e catálogos após suas descrições. As espécies de Scleronema distribuem-se na bacia do rio da Plata e drenagens costeiras atlânticas no sul do Brasil, sul do Paraguai, nordeste da Argentina e Uruguai, habitando rios e riachos ao longo do Pampa com fundos de areia ou cascalho. Dois grupos de espécies supostamente monofiléticos, o grupo S. minutum e o grupo S. operculatum, são reconhecidos no gênero e os padrões de distribuição de suas espécies são discutidos.

The species of the bee genus Centris Fabricius, 1804 described by Curt Schrottky (Hymenoptera: Apidae)

In this paper the primary types of Centris bees described by the German entomologist Curt Schrottky were studied. The type specimens of C. anisitsi, C. brethesi, C. ehrhardti, C. garleppi, C. garleppi var. unifasciata, C. pectoralis var. flava, C. pocograndensis, and C. xanthocnemis var. perflava were analyzed, providing notes on their current status and depository. To stabilize the application of the name C. ehrhardti a lectotype was designated. Notes and photographs of selected types are also provided.(AU)

A contribution to the genera Plectonotum Gorham and Hyponotum Wittmer, with the description of sixteen new species from Peru (Coleoptera, Cantharidae)

Sixteen species of Peruvian Dysmorphocerinae (Cantharidae) are described as new (regions in parenthesis): Hyponotum macrocephalum sp. nov. (Huanuco); H. succhabamba sp. nov. (Cajamarca); Plectonotum altomayo sp. nov. (Amazonas); P. amazonas sp. nov. (Amazonas); P. bicoloricolle sp. nov. (Huanuco); P. carpish sp. nov. (Huanuco); P. celendin sp. nov. (Cajamarca); P. costae sp. nov. (Cajamarca); P. huariaca sp. nov. (Pasco and Huanuco); P. huascaran sp. nov. (Ancash); P. huertoae sp. nov. (Cajamarca); P. leymebamba sp. nov. (Amazonas); P. luteipes sp. nov. (Amazonas); P. oxapampa sp. nov. (Pasco); P. rubrithorax sp. nov. (Huanuco); P. shipasbamba sp. nov. (Amazonas). A lectotype is designated for Plectonotum longissimum (Pic, 1927) for which a redescription is provided. Plectonotum ruficolleWittmer, 1988, homonym of Plectonotum ruficollePic, 1926, is renamed as Plectonotum neoruficolle nom. nov. New keys are proposed in English and Spanish for the identification of the Peruvian species of the genus Plectonotum and the South American species of the genus Hyponotum Wittmer, together with macrophotographs of habitus, details of pronotum, male genitalia and a cartographic representation of their distribution.(AU)

Systematic revision of the Neotropical catfish genus Scleronema (Siluriformes: Trichomycteridae), with descriptions of six new species from Pampa grasslands

The Neotropical genus Scleronema is revised based on the re-examination of the type specimens and 1,713 newly collected specimens. Scleronema is diagnosed from other trichomycterids by the following unambiguous derived characters: fleshy flap at the base of the maxillary barbell; skin flap in the posterior margin of the opercle; articulation between the autopalatine and the vomer ventrally located, with the medial margins of the autopalatines very close to each other; and autopalatine with an interrupted or not interrupted ossified arch-shaped process on its dorsal surface forming a canal. Scleronema minutum and S. operculatum are redescribed, S. angustirostre is considered a junior synonym of S. minutum, and six new species are described. A lectotype is designated for Trichomycterus minutus. The type localities of S. angustirostre, S. minutum, and S. operculatum are reviewed in order to correct erroneous information cited in articles and catalogs subsequent to the original descriptions. Species of Scleronema are geographically distributed in the La Plata basin and Atlantic coastal drainages from Southern Brazil, Southern Paraguay, Northeastern Argentina and Uruguay. They inhabit rivers or streams with sand- or gravel-bottoms across the Pampa grasslands. We provide evidences to recognize two putative monophyletic units within the genus, namely the S. minutum species group and the S. operculatum species group, and discuss the distribution patterns of their species.(AU)

O gênero Neotropical Scleronema é revisado com base na análise do material-tipo e outros 1.713 espécimes recentemente coletados. Scleronema é diagnosticado de outros tricomicterídeos pelos seguintes caracteres derivados não ambíguos: aba de pele na base do barbilhão maxilar; aba de pele na margem posterior do opérculo; articulação entre o autopalatino e o vômer posicionada ventralmente, deixando as margens mediais dos autopalatinos muito próximas entre si; e o autopalatino com um processo com formato de arco na sua superfície dorsal. Scleronema minutum e S. operculatum são redescritas, S. angustirostre é considerada um sinônimo júnior de S. minutum e seis novas espécies são descritas. Um lectótipo é designado para S. minutum. As localidades-tipo de S. angustirostre, S. minutum e S. operculatum são revisadas com o intuito de corrigir informações errôneas citadas em artigos e catálogos após suas descrições. As espécies de Scleronema distribuem-se na bacia do rio da Plata e drenagens costeiras atlânticas no sul do Brasil, sul do Paraguai, nordeste da Argentina e Uruguai, habitando rios e riachos ao longo do Pampa com fundos de areia ou cascalho. Dois grupos de espécies supostamente monofiléticos, o grupo S. minutum e o grupo S. operculatum, são reconhecidos no gênero e os padrões de distribuição de suas espécies são discutidos.(AU)

Cercopoidea types (Hemiptera-Cicadomorpha) housed at the Museo de la Plata entomological collection (Argentina)

Type material of 11 species from seven genera of Cercopoidea is housed at the Entomology Division of the Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. The types listed herein correspond to species described by C. Berg (10 spp.) and Lallemand (1 sp.). The collection contains 24 type specimens. Lectotype and paralectotypes of Deois (Deois) knoblauchii (Berg), Kanaima katzensteinii (Berg), Mahanarva (Ipiranga) aguirrei (Berg), Tomaspis argentina Berg [= Deois terrea (Germar)], T. perezii Berg [= Deois terrea (Germar)] and T. platensis Berg are designated. Comparison of their original descriptions with the label information supports the existence of 2 holotypes, 6 lectotypes, 10 paralectotypes and 6 syntypes. The following information is given for each species: original species names, taxonomic catalogue, bibliographic references, type category, number of specimens, gender, Museo de La Plata code numbers, and transcription of data from labels (country, province, locality, date of collection, collector’s name, and hosts). Information about subsequent nomenclatural changes with corresponding references, the state of preservation of the specimens in each series and pictures of each species are also provided.

Cercopoidea types (Hemiptera-Cicadomorpha) housed at the Museo de la Plata entomological collection (Argentina)

Type material of 11 species from seven genera of Cercopoidea is housed at the Entomology Division of the Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. The types listed herein correspond to species described by C. Berg (10 spp.) and Lallemand (1 sp.). The collection contains 24 type specimens. Lectotype and paralectotypes of Deois (Deois) knoblauchii (Berg), Kanaima katzensteinii (Berg), Mahanarva (Ipiranga) aguirrei (Berg), Tomaspis argentina Berg [= Deois terrea (Germar)], T. perezii Berg [= Deois terrea (Germar)] and T. platensis Berg are designated. Comparison of their original descriptions with the label information supports the existence of 2 holotypes, 6 lectotypes, 10 paralectotypes and 6 syntypes. The following information is given for each species: original species names, taxonomic catalogue, bibliographic references, type category, number of specimens, gender, Museo de La Plata code numbers, and transcription of data from labels (country, province, locality, date of collection, collectors name, and hosts). Information about subsequent nomenclatural changes with corresponding references, the state of preservation of the specimens in each series and pictures of each species are also provided.(AU)

Revalidation and redescription of Steindachnerina nigrotaenia and redescription of S. insculpta (Characiformes: Curimatidae)

Steindachnerina nigrotaenia is resurrected from the synonym of S. brevipinna and considered a valid species. The previous designation of the lectotype of S. nigrotaenia is considered invalid and a new lectotype is designated herein. Steindachnerina nigrotaenia and S. insculpta are redescribed based on type specimens and on additional material from the rio Paraguai and the upper rio Paraná basins, respectively. The two species can be separated by the number of scales of the lateral line and of the transverse series and by phylogenetic analyses of molecular data.(AU)

Steindachnerina nigrotaenia é retirada da sinonímia de S. brevipinna e considerada uma espécie válida. A designação do lectótipo de S. nigrotaenia é considerada inválida e um novo lectótipo é aqui designado. Steindachnerina nigrotaenia e S. insculpta são redescritas com base no material tipo e em exemplares adicionais das bacias do rio Paraguai e alto rio Paraná, respectivamente. As duas espécies se diferenciam pelo número de escamas da linha lateral e da série transversal e por análises filogenéticas de dados moleculares.(AU)

On the identity of Porcellana paivacarvalhoi Rodrigues da Costa, 1968 (Crustacea: Anomura: Porcellanidae)

Porcellana paivacarvalhoi Rodrigues da Costa, 1968, described from southeastern Brazil (São Sebastião, São Paulo), is morphologically similar to the eastern Atlantic P. platycheles (Pennant, 1777), and also to the west African P. africana Chace, 1956. The synonymy between P. paivacarvalhoi and P. platycheles was proposed by previous authors without examination of any specimens of P. platycheles, nor did they considered the morphological similarities between P. paivacarvalhoi and P. africana. This synonymy has been implicitly accepted without further analysis. The recent discovery of one male and two females syntypes of P. paivacarvalhoi has prompted new investigations into the status of P. paivacarvalhoi as a junior synonym either of P. platycheles or P. africana. Porcellana paivacarvalhoi is redescribed and illustrated based upon its lectotype herein designated. It is confirmed to be a junior synonym of P. platycheles; all evidence suggests that P. africana is a distinct, separate species. All previous records of P. platycheles from the Brazilian coast are reviewed. Its presence in southeastern Brazil in the late 1960’s most probably represents an historical case of human-mediated introduction by shipping activities. Porcellana platycheles did not manage to establish itself in São Sebastião, nor has it been recorded subsequently elsewhere in Brazil.

Revalidation and redescription of Steindachnerina nigrotaenia and redescription of S. insculpta (Characiformes: Curimatidae)

Steindachnerina nigrotaenia is resurrected from the synonym of S. brevipinna and considered a valid species. The previous designation of the lectotype of S. nigrotaenia is considered invalid and a new lectotype is designated herein. Steindachnerina nigrotaenia and S. insculpta are redescribed based on type specimens and on additional material from the rio Paraguai and the upper rio Paraná basins, respectively. The two species can be separated by the number of scales of the lateral line and of the transverse series and by phylogenetic analyses of molecular data.(AU)

Steindachnerina nigrotaenia é retirada da sinonímia de S. brevipinna e considerada uma espécie válida. A designação do lectótipo de S. nigrotaenia é considerada inválida e um novo lectótipo é aqui designado. Steindachnerina nigrotaenia e S. insculpta são redescritas com base no material tipo e em exemplares adicionais das bacias do rio Paraguai e alto rio Paraná, respectivamente. As duas espécies se diferenciam pelo número de escamas da linha lateral e da série transversal e por análises filogenéticas de dados moleculares.(AU)

On the identity of Porcellana paivacarvalhoi Rodrigues da Costa, 1968 (Crustacea: Anomura: Porcellanidae)

Porcellana paivacarvalhoi Rodrigues da Costa, 1968, described from southeastern Brazil (São Sebastião, São Paulo), is morphologically similar to the eastern Atlantic P. platycheles (Pennant, 1777), and also to the west African P. africana Chace, 1956. The synonymy between P. paivacarvalhoi and P. platycheles was proposed by previous authors without examination of any specimens of P. platycheles, nor did they considered the morphological similarities between P. paivacarvalhoi and P. africana. This synonymy has been implicitly accepted without further analysis. The recent discovery of one male and two females syntypes of P. paivacarvalhoi has prompted new investigations into the status of P. paivacarvalhoi as a junior synonym either of P. platycheles or P. africana. Porcellana paivacarvalhoi is redescribed and illustrated based upon its lectotype herein designated. It is confirmed to be a junior synonym of P. platycheles; all evidence suggests that P. africana is a distinct, separate species. All previous records of P. platycheles from the Brazilian coast are reviewed. Its presence in southeastern Brazil in the late 1960s most probably represents an historical case of human-mediated introduction by shipping activities. Porcellana platycheles did not manage to establish itself in São Sebastião, nor has it been recorded subsequently elsewhere in Brazil.(AU)

Redescription of Schizodon dissimilis and appraisal of the dark barred species of the genus (Characiformes: Anostomidae)

Schizodon dissimilis is redescribed on the basis of syntypes and non-type specimens from the Parnaíba, Jaguaribe and Mearim rivers, and lectotype and paralectotypes are designated. Schizodon dissimilis is distinct from the Amazonian and southeastern Brazil congeners by having four dark brown vertical bars without a midlateral dark brown stripe or a dark blotch on caudal peduncle. When compared with the northeastern Brazilian Schizodon and those from the São Francisco river, and with the remaining dark barred species S. australis, S. borellii, S. corti, S. fasciatus and S. intermedius, it is diagnosed by a combination of lateral line scale counts, color pattern and body proportions. The color pattern distinguishes S. dissimilis from S. fasciatus and the meristic and morphometric data are important in separating S. dissimilis from S. intermedius and S. borellii. Schizodon dissimilis and S. fasciatus have disjunct distributions, with the first occurring in northeastern basins, and the second widely distributed through the Amazon basin and rivers draining northward from the Guyana Shield. Schizodon intermedius and S. borellii are respectively native to the upper Paraná and Paraguay river basins while S. australis is known from the Paraná-Uruguay system and S. corti was described from Maracaibo, Venezuela.(AU)

Schizodon dissimilis é redescrita com base em síntipos e outros espécimes coletados nos rios Parnaíba, Jaguaribe e Mearim, e um lectótipo e paralectótipos são designados. Schizodon dissimilis é distinta das espécies Amazônicas e de seus congêneres do sudeste do Brasil por possuir quatro barras transversais castanho-escuras sem uma listra longitudinal mediana ou mácula escura no pedúnculo caudal. Quando comparada com as espécies de Schizodon do nordeste brasileiro e do rio São Francisco, assim como com as demais espécies com barras transversais escuras S. australis, S. borellii, S. corti, S. fasciatus e S. intermedius, se distingue pela combinação da contagem de escamas da linha lateral com padrão de colorido e proporções corporais. O padrão de colorido separa definitivamente S. dissimilis de S. fasciatus, enquanto os dados merísticos e morfométricos são importantes para distinguir S. dissimilis de S. intermedius e S. borellii. Schizodon dissimilis e S. fasciatus têm distribuição disjunta, a primeira nativa dos rios da região nordeste e a segunda amplamente distribuída pela Bacia Amazônica e Guiana. Schizodon intermedius e S. borellii são nativas das bacias do alto rio Paraná e do rio Paraguai respectivamente, enquanto e S. australis é conhecida da bacia Paraná-Uruguai e S. corti foi descrita do Lago Maracaibo na Venezuela.(AU)