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The gross brain morphology and the peripheral olfactory organ of Microglanis garavelloi are described throughout development, and the relationship of these organs to the general behaviour of the species is discussed. During the development, the main brain subdivisions undergo a series of morphological changes keeping a relatively constant volume increase. However, we observed different growth rates in the brains of males and females when these were compared. During the maturation process, a series of hormonal events result in the development of some secondary sexual traits in the brain of male specimens, like faster growth rate of brain areas linked to motor control, olfactory and visual responses. The number of olfactory-organ lamellae increases continuously in both males and females, during their maturation period. These results suggest that changes may be caused by cognitive demands that this species is exposed to throughout its lifespan. The gross morphological arrangement of the central nervous system indicates shared patterns with other members of the family Pseudopimelodidae.

Cetopsis varii sp. nov. Cetopsidae (Cetopsinae) is described from the Río Meta basin in eastern Colombia, at middle portions of the Río Orinoco basin. The new species differs from congeners by a combination of features: the absence of a humeral spot, presence of eye, conical teeth on vomer and dentary and rounded posterior nares, along with details of body, dorsal and caudal-fin pigmentation. The osteology of the new species is investigated through high-resolution X-ray computed tomography and cleared and stained specimens. Data thus obtained are used to code the new species for character states utilized in a previous phylogenetic analysis of Cetopsidae. Analysis of the expanded matrix shows that C. varii is the sister group to C. orinoco.

A new species of Hyphessobrycon is described from the Rio Juma, a tributary of the lower Rio Aripuana-Rio Madeira basin, Amazonas, Brazil. Hyphessobrycon platyodus can be distinguished from its congeners by the: presence of an elongated dorsal fin in adult males, 25-28 branched anal-fin rays and absence of dark blotches from the dorsal fin and caudal peduncle. The presence of multicuspid teeth in species of Characidae and its relation with feeding habits are briefly commented on.

A new species of Cetopsis is described from Guiana Shield drainages in Guyana and Suriname. The new species is found in the Konawaruk River and tributaries, Essequibo River basin, Guyana, and in the Mauritie Creek, tributary to the Tempati River, upper Commewijne River basin, Suriname. The new taxon can be distinguished from all congeners by a combination of features: dark spots on sides of the body eye-sized or larger, dark, bilobed patch at the base of the caudal fin, absence of a dark humeral spot, absence of dark pigmentation along the fin-membrane posterior to the first dorsal-fin ray, dark pigmentation at the base of the dorsal fin, dark spots extending ventrally to the bases of anal-fin rays, and 41 total vertebrae with 28 caudal vertebrae. Data on internal anatomy of the new species were incorporated into a previously-published phylogenetic analysis and resolves the position of the new species as the sister group of C. motatanensis, from Lago Maracaibo basin. The new Cetopsis is the first species of the genus known to occur exclusively in the Guiana Shield.

A new species of the Copionodontinae genus Copionodon is described from the riacho do Mosquito, tributary to rio Santo Antônio, rio Paraguaçu basin in the Diamantina Plateau, Bahia State, northeastern Brazil. This species represents the northernmost occurrence of the subfamily yet known and is a relictual population, apparently restricted to an underground sector of the stream and its immediate downstream exit. The new species can be readily recognized by the combination of the presence of opercular odontodes, the mostly uniform coloration of the body, and the lack of a free orbital rim. Despite several troglomorphic traits shared between the new species and Glaphyropoma spinosum, the two species are not closest relatives and all such similarities are convergent adaptations to the subterranean habitat. A CT-Scan study of the holotype of the new species is presented and allows a view into the details of copionodontine anatomy with unprecedented clarity. RESUMO Uma nova espécie de Copionodon (Copionodontinae) é descrita do riacho do Mosquito, tributário do rio Santo Antônio, bacia do rio Paraguaçu, Chapada Diamantina, Bahia, Brasil. Essa espécie representa a ocorrência mais ao norte da subfamília até então conhecida como uma população relictual, aparentemente restrita a um setor subterrâneo do riacho e sua saída à jusante. A nova espécie pode ser reconhecida pela combinação de odontódeos presentes no opérculo, coloração uniforme do corpo e ausência de margem orbital livre. Apesar de alguns caracteres troglomórficos compartilhados entre a nova espécie e Glaphyropoma spinosum, as duas espécies não são proximamente relacionadas e todas essas similaridades são interpretadas como adaptações convergentes ao ambiente subterrâneo. É apresentado um estudo de tomografia computadorizada do holótipo da nova espécie que permite a visualização de detalhes da anatomia interna de copionodontinae com clareza sem precedentes.

Among the order Characiformes, secondary sexual dimorphism is commonly associated to the occurrence of bony hooks on fins, shape and length of the dorsal and anal fins, and sexual dichromatism. The analysis of a new miniature Characidae species of the genus Tyttobrycon, described herein, yielded to the discovery of a sexually dimorphic trait related to nostril aperture and number of olfactory lamellae. In this type of dimorphism, mature males present larger nostril aperture and higher number of olfactory lamella than females. A dimorphic olfactory organ is for the first time recorded and described for a member of the Characiformes. Gross morphology and development of brain and peripheral olfactory organ of Tyttobrycon sp. n. are described and compared to other species of Characidae. It is hypothesized that such dimorphic trait is related to male-male detection during cohort competition in small characids. The new species of Tyttobrycon is diagnosed from its congeners by the number of branched anal-fin rays (19-21) and the absence of a caudal-peduncle blotch. It occurs in a small tributary of Rio Madeira basin, near to the limit between Brazil and Bolivia, Acre State, Brazil.

A família de Siluriformes Neotropicais Cetopsidae possui cinco gêneros e 43 espécies válidas, com ampla distribuição nas regiões norte e central da América do Sul, tanto cis- como trans-andina. Cetopsidae é proposta como um grupo monofilético, suportado pela maioria dos estudos morfológicos e moleculares. Os estudos evolutivos sobre o sistema nervoso de bagres neotropicais são bastante escassos, apesar desse complexo apresentarimportantes modificações potencialmente informativas para estudos de inferência filogenética. Para testar a significância dos caracteres neuroanatômicos em filogenias, a morfologia externa das principais subdivisões encefálicas de Cetopsidae foi descrita, ilustrada e interpretada. Além disso, análises comparativas do desenvolvimento desse complexo foram realizadas em Helogenes marmoratus e Cetopsis gobioides com o intuito de estabelecer homologias e compreender suas modificações ontogenéticas. Os caracteres foram delimitados e testados separadamente em análises filogenéticas e posteriormente combinados com caracteres morfológicos e moleculares com diferentes métodos de análise. Para determinar o volume de cada região analisada, um modelo elipsoide foi utilizado. Amplas comparações baseadas no formato, posição relativa e volume das principais regiões encefálicas são apresentadas para a maioria das espécies representativas de todos os gêneros de Cetopsidae. As mesmas comparações também foram realizadas ao longo do desenvolvimento de Helogenes marmoratus e Cetopsis gobioides. Além disso, comparações com integrantes de outras famílias filogeneticamente relacionadas em Siluriformes forneceram um amplo contexto para um maior entendimento das principais modificações evolutivas que moldaram o encéfalo doscetopsídeos. Análises filogenéticas de todos os caracteres morfológicos foram primeiramente conduzidas em separado, e posteriormente em matrizes concatenadas sob o critério da Parcimônia. Análises Bayesianas com sequências alinhadas e concatenadas de três genes mitocondriais (COI, 16S e Cytb) foram implementadas. Por fim, análises filogenéticas com todos os dados combinados foram conduzidas sob os critérios da Parcimônia e Bayesiano. Padrões morfológicos distintos foram definidos para cada uma das duas principais subdivisões de Cetopsidae, as subfamílias Helogeninae e Cetopsinae. Poucas variações intraespecíficas na morfologia externa do encéfalo xii existem entre todas as espécies examinadas aqui. As modificações observadas ao longo do desenvolvimento do encéfalo de Helogenes marmoratus e Cetopsis gobioides foram utilizadas para a formulação correta de caracteres e seus estados. Todos os gêneros foram recuperados como grupos monofiléticos pelos caracteres neuroanatômicos.Mapeamentos filogenéticos revelaram alguns padrões morfológicos sugestivos com especializações alimentares e outras características de história de vida correlacionadas ao sistema nervoso central. Os caracteres morfológicos e moleculares se mostraram bastante congruentes nas hipóteses filogenéticas, comas incongruências restritas à tribo Cetopsini. Todas as análises recuperaram Helogeninae como grupo-irmão dos demais cetopsídeos, seguido por Cetopsidiini, Denticetopsini e Cetopsini como grupos-irmãos sucessivos.Os resultados obtidos no presente estudo suportam a ideia de que análises amplas e concatenadas de dados morfológicos e moleculares resultam em hipóteses de relacionamentos robustas e bem suportadas. Os caracteres neuroanatômicos são altamente informativos para inferências filogenéticas, que podem ser exploradospara uma maior compreensão da evolução de Otophysi. The Neotropical South American catfish Cetopsidae is a family of Siluriformes that includes five genera and 43valid species distributed over a large portion of northern and central regions of South America, on both sides of the Andean cordilleras. The monophyly of the family is supported by several previous studies, based on both morphological and molecular characters. Despite the scarcity of evolutionary studies on the nervous system of neotropical catfishes, that complex shows great variation potentially informative for phylogenetic inference. In order to test the significance of neurological traits in a phylogenetic framework, the gross morphology of brain subdivisions in the catfish family Cetopsidae is described, illustrated and interpreted. In addition, comparative analyzes of the development of this complex were carried out in Helogenes marmoratus and Cetopsis gobioidesin order to establish homologies and ontogenetic transformations. Characters were delimited and tested separately in phylogenetic analyzes and later combined with other morphological and molecular characters with different methods of analysis. The volume of major brain subdivision was calculated by an ellipsoid model. A comprehensive comparison based on shape, relative position, and volume of the main brain subdivisions is presented for representative species of all genera and most available species in the family. The same comparisons were also made throughout the development of Helogenes marmoratus and Cetopsis gobioides. Comparisons with other phylogenetically related siluriform families provide a broader context for the understanding of the main evolutionary transformations which shaped the cetopsid brain. Phylogenetic analyzes of all morphological characters were first conducted separately, and later in matrices concatenated under the Parsimony criterion. Bayesian analyzes of three aligned and concatenated mitochondrial gene sequences (COI, 16S and Cytb) were implemented. Analyzes of all the data combined were conducted under both Parsimony and Bayesian criteria. Profoundly distinct morphological patterns are identified for each of the two main cetopsid subdivisions, subfamilies Helogeninae and Cetopsinae. Little intraspecific variation on major subdivisions of the brain exists in species examined herein. The modifications observed throughout the development of the brain inHelogenes marmoratus and Cetopsis gobioides were used for the correct delimitation xiv of characters and their states. The monophyly of all genera is supported by putative neuroanatomic characters. Phylogenetic mapping reveals recurrent morphological patterns suggestive of an association with specific feeding specializations and other life-history traits. Morphological and molecular characters were highly congruent in phylogenetic hypotheses, with inconsistencies restricted to the tribe Cetopsini. All analyzes recovered Helogeninae as thesister group toall remaining cetopsids, followed by Cetopsidiini, Denticetopsini and Cetopsini as successive sister groups. Results of the present study support the idea that large and concatenated analyzes of morphological and molecular characters result in robust well-supported hypotheses of relationships. Neuroanatomical characters are highly informative for phylogenetic inferenceand area promising field to be explored in understanding the evolution of Otophysi.

Made available in DSpace on 2018-12-11T17:24:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The southern region of Brazil is characterized by high species diversity and endemism of freshwater fishes distributed across geographically isolated river basins. Microglanis cottoides has a widespread range across these river basins and occurs in sympatry with other endemic species of the genus (e.g. M. cibelae, M. eurystoma, and M. malabarbai). Herein we tested the monophyly of M. cottoides and presented for the first time information about the molecular phylogeny of species in the genus. The results suggest that M. cottoides currently forms a non-monophyletic group which includes populations endemic to the Uruguay River basin that are more closely related to M. malabarbai, and excludes M. cibelae, found to be nested within M. cottoides. Based on an integrative approach using morphological and molecular data, we propose M. cibelae as a junior synonym of M. cottoides, and the populations of the Uruguay River basin previously assigned to M. cottoides in fact belong to M. malabarbai. Our molecular phylogeny shows that M. cottoides is sister to M. parahybae, which is also a coastal species, and M. malabarbai is sister of M. garavelloi, both endemic to inland river basins. The time-calibrated phylogeny indicates that the separation between inland and the coastal clades occurred in the Tertiary period, and that the species within the coastal basins diverged in the Pliocene, which overlaps with the diversification times estimated for the two inland species as well. This pattern of diversification corroborates some previous studies with other fishes from the same region. Laboratório de Genética e Ecologia Animal Departamento de Biologia Geral Universidade Estadual de Londrina Department of Organismic and Evolutionary Biology Museum of Comparative Zoology Harvard University Universidade de São Paulo Museu de Zoologia da USP Faculdades Integradas de Ourinhos Laboratório de Biologia e Genética de Peixes Departamento de Morfologia Instituto de Biociências Universidade Estadual Paulista -UNESP Departamento de Zoologia Universidade Federal do Rio Grande do Sul Departamento de Biologia Animal e Vegetal Universidade Estadual de Londrina Laboratório de Biologia e Genética de Peixes Departamento de Morfologia Instituto de Biociências Universidade Estadual Paulista -UNESP CNPq: 478336/2013-6

This study presents a list of species from igarapés tributaries of the rio Acre, Acre State, Brazil. Fish assemblages were sampled in October 2009, August and October 2010, using standard ichthyological gear, along fifteen sampling sites. A total of 11,395 specimens, distributed in 94 species, 24 families and six orders were collected. The most species-rich orders were Characiformes with 45 species (48.4%) and Siluriformes with 33 species (34.7%); from which Serrapinnus gr. microdon (22.4%), Otocinclus vittatus (20.4%), Phenacogaster pectinatus (10.9%), Brachychalcinus copei (5.8%) and Knodus sp. (5.3%) represented 64.8 % of the specimens captured. The species accumulation curve does not present a stabilization tendency, indicating that, additional sampling can increase the number of species. This study has a high importance for the knowledge of the rio Acre fish fauna composition and adds 52 new records of species to the fish fauna of the rio Purus.

Neste trabalho foi realizado um estudo comparativo da morfologia externa do sistema nervoso central (SNC) das espécies da família Pseudopimelodidae. A importância dos estudos do SNC dos Siluriformes neotropicais torna-se evidente frente à grande diversidade morfológica das espécies reconhecidas atualmente. Os encéfalos dos peixes examinados foram dissecados, e após a secção dos nervos cranianos e da medula espinhal, retirados da cabeça para posterior morfometria de suas principais subdivisões. Com isso, descrevemos detalhadamente a morfologia externa do SNC de Pseudopimelodus bufonius, que pertence ao gênero tipo da família Pseudopimelodidae, e o comparamos com P. charus e P. mangurus. Além disso, o posicionamento filogenético dos gêneros dessa família foi estudado por meio de 41 caracteres obtidos da morfologia externa do SNC de 28 táxons terminais, incluindo as espécies do grupo externo. Um cladograma de consenso estrito foi obtido a partir de duas árvores mais parcimoniosas. Essa árvore apresentou 99 passos, com índices de consistência e retenção de 0,62 e 0,85, respectivamente. Pudemos notar alguns padrões na forma, posição e tamanho das subdivisões do SNC para todas as espécies. Foram feitas comparações intraespecíficas de acordo com o tamanho relativo e forma das principais subdivisões do SNC. Com as análises filogenéticas, Heptapteridae é a família que se manteve como grupo irmão do clado composto por (Phreatobius sanguijuela (Pimelodidae, Pseudopimelodidae)). As relações filogenéticas entre os gêneros de Pseudopimelodidae também foram estudadas e o grupo contendo (Pseudopimelodus aff. pulcher (Cruciglanis, Pseudopimelodus)) foi considerado irmão do grupo contendo (Lophiosilurus (Cephalosilurus (Batrochoglanis, Microglanis))). Ainda propomos algumas sinapomorfias do grupo de espécies Pseudopimelodus aff. pulcher, as quais reforçam sua monofilia dentro da família. As hipóteses propostas no presente estudo coincidem com as de algumas análises recentemente realizadas. A relação da família Pseudopimelodidae de maior proximidade com Pimelodidae, assim como este clado tendo mais proximidade com Phreatobius e Heptapteridae como grupo irmão de todas as famílias, corrobora as mais recentes pesquisas, que utilizam dados de caracteres morfológicos e de genética molecular. Comparative study of the gross morphology of central nervous system (CNS) among species of the family Pseudopimelodidae was made. Improvements studies of CNS of neotropical Siluriformes becomes evident due to the high morphological diversity of species currently recognized. After section of the cranial nerves and spinal cord, the brains were removed and major subdivisions were measured. Gross morphology of CNS of Pseudopimelodus bufonius, which belongs to genre type of family Pseudopimelodidae, was described and compared with congeners. Furthermore, the phylogenetic position of all genera of family was studied by 41 characters obtained from gross morphology of CNS. Twenty-eight taxa including out group species were analyzed. From two most parcimonious tree a strict consensus cladogram was obtained. These trees had 99 steps and consistency and retention indices of 0.62 and 0.85, respectively. In all examined species patterns in shape, position and size of major subdivisions of CNS were found and compared. Family Heptapteridae is sister group of clade comprising (Phreatobius Sanguijuela (Pimelodidae, Pseudopimelodidae)). Group comprising (Pseudopimelodus aff. Pulcher (Cruciglanis, Pseudopimelodus)) was considered sister group of clade comprising (Lophiosilurus (Cephalosilurus (Batrochoglanis, Microglanis))). Monofily of Pseudopimelodus aff pulcher species-group by some synapomorphies were proposed. The hypotheses showed in this study are consistent with the analysis of some recently performed where greater proximity among Pseudopimelodidae and Pimelodidae was proposed. Furthermore, Phreatobius sanguijuela located as sister group of this clade. Family Heptapteridae was proposed as sister group of all groups which supports the latest research using morphological and molecular datas.