Maturidade do ovário no cascudo Hypostomus strigaticeps (Siluriformes, Loriicaridae)

This work studied the ovarian development of the armored catfish Hypostomus strigaticeps. Between July 2002 and June 2005, 332 females were collected monthly from the Corumbatai River, São Paulo State [long dash] Brazil. The ovaries were processed using routine histological techniques [long dash] paraffin inclusion and 5 pm thick sections stained in hematoxylin-cosin. Six types of oocytes were observed: Chromatin-nucleolus, Perinncleolar, Cortical-alveolus, Vitellogenic, Ripe and Atresic. Four maturity stages were created based on macroscopic and microscopic morphological observations, as well as on analysis of the gonadossomatic index (GSI): Rest, Maturation, Ripe and Spawned.

Cytogenetic analysis of five Hypostomus species (Siluriformes, Loricariidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Unilatus unilatus Mizelle & Kritsky, 1967 (Monogenea, Ancyrocephalinae) in Hypostomus spp. (Siluriformes, Loricariidae) from the Chavantes reservoir, So Paulo State, Brazil

In this paper, the occurrence and new morphological data of Unilatus unilatus Mizelle et Kritsky, 1967 from the gills of Hypostomus strigaticeps (Regan, 1907), Hypostomus regani (Ihering, 1905), and Hypostomus iheringii (Regan, 1908) from the Chavantes reservoir, So Paulo State, Brazil are reported. Unilatus unilatus from this reservoir presents differences in relation to the holotype previously described such as, eggs with no bifid or trifid filament and a rounded termination, anterior bar slightly curved with a posterior projection, and posterior bar which may present three shapes. This is the first record of U. unilatus in southeastern Brazil outside the Amazon River Basin, with H. strigaticeps, H. regani and H. iheringii as new hosts.

First case of an infection of the metacercariae of Austrodiplostomum compactum (Lutz, 1928) (Digenea, Diplostomidae) in Hypostomus regani (Ihering, 1905) (Siluriformes: Loricariidae).

Austrodiplostomum compactum (Lutz, 1928) (Digenea, Diplostomidae) was recorded infecting the eyes of a Hypostomus regani (Ihering, 1905) (Siluriformes: Loricariidae). This is the first report of a loricarid fish infected with A. compactum.

Diet and capture of Hypostomus strigaticeps (Siluriformes, Loricariidae) in a small brazilian stream: relationship with limnological aspects

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A New Species of Hypostomus (Siluriformes: Loricariidae) from the Upper Rio Paraguay Basin, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Habitat use by two species of Hypostomus (Pisces, Loricariidae) in southeastern brazilian streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Descrição cariotípica de possíveis novas espécies do complexo Hypostomus ancistroides e outros Hypostominae

Cytogenetic analyses were performed in four species of the Hypostominae subfamily, three from Hypostomus (Hypostomini) genus and Rhinelepis aspera (Rhinelepini). Three populations of Hypostomus ancistroides were analyzed, which had 2n=68 chromosomes, but presented different karyotype formulas. Hypostomus regani and H. strigaticeps, both from Ivaí river, showed 2n=72 chromosomes with two distinct cytotypes. In turn, R. aspera of the upper Paraná river basin presented 2n=54 chromosome. Multiple Nucleolar Organizer Regions (NORs) have been evidenced by silver nitrate staining in species of Hypostomus and single NOR in R. aspera. The observed variation in the chromosome number and the marked variability in karyotype formulas and NORs reveal a certain amount of karyotype variation in the genus Hypostomus suggesting the probable existence of cryptic species with independent chromosome traits. Therefore, our data can be of great value in discriminating species and understanding their chromosomal evolution.

Karyotypic diversity and evolutionary trends in the neotropical catfish genus Hypostomus lacépède, 1803 (Teleostei, Siluriformes, Loricariidae)

The family Loricariidae with 813 nominal species is one of the largest fish families of the world. Hypostominae, its more complex subfamily, was recently divided into five tribes. The tribe Hypostomini is composed of a single genus, Hypostomus Lacépède, 1803, which exhibits the largest karyotypic diversity in the family Loricariidae. With the main objective of contributing to a better understanding of the relationship and the patterns of evolution among the karyotypes of Hypostomus species, cytogenetic studies were conducted in six species of the genus from Brazil and Venezuela. The results show a great chromosome variety with diploid numbers ranging from 2n=68 to 2n=76, with a clear predominance of acrocentric chromosomes. The Ag-NORs are located in terminal position in all species analyzed. Three species have single Ag-NORs (Hypostomus albopunctatus (Regan, 1908), H. prope plecostomus (Linnaeus, 1758), and H. prope paulinus (Ihering, 1905)) and three have multiple Ag-NORs (H. ancistroides (Ihering, 1911), H. prope iheringi (Regan, 1908), and H. strigaticeps (Regan, 1908)). In the process of karyotype evolution of the group, the main type of chromosome rearrangements was possibly centric fissions, which may have been facilitated by the putative tetraploid origin of Hypostomus species. The relationship between the karyotype changes and the evolution in the genus is discussed. © Anderson Luis Alves et al.

Phylogeography of Hypostomus strigaticeps (Siluriformes: Loricariidae) inferred by mitochondrial DNA reveals its distribution in the upper Paraná River basin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mapping five repetitive DNA classes in sympatric species of Hypostomus (Teleostei: Siluriformes: Loricariidae): analysis of chromosomal variability

Fish belonging to the genus Hypostomus are known for exhibiting a striking diversity in its karyotype structure, however the knowledge concerning the distribution patterns of heterochromatin and location of repetitive DNA sequences in the karyotypes is still limited. Aiming a better understanding of the chromosomal organization in this group, we analyzed three sympatric species of Hypostomus collected in the Hortelã stream, a component of the Paranapanema River basin, Botucatu/SP/Brazil. The analyses involved the cytogenetic characterization and chromosomal mapping of repetitive sequences and intra/interspecific comparisons using sequences of the cytochrome C oxidase subunit I. The results revealed that H. ancistroides presents a karyotype with 2n = 68 chromosomes, H. strigaticeps 2n = 72 chromosomes, and H. nigromaculatus 2n = 76 chromosomes. In addition to differences found in the diploid number, it was also observed variations in karyotypic formulae, amount of constitutive heterochromatin, and location of nucleolus organizer regions. The cytogenetic mapping of 5S and 18S rDNA, as well as of the H3 histone gene, disclosed a differential dispersion process among the three species. In some cases the Rex1 transposable element showed to be co-located with 5S rDNA sites. The molecular analyses support the cytogenetic data and represent an additional tool for the characterization of the analyzed species. The results evidenced that chromosomal variations are not restricted to differences in diploid number or karyotypic macrostructure in the genus Hypostomus, indicating that events such as transposition of heterochromatin and rDNA segments may participate in the differentiation process occurred in these species. © 2013 Springer Science+Business Media Dordrecht.

Dieta e morfologia trófica de espécies do gênero Hypostomus Lacépède, 1803 (Ostariophysi, Loricariidae) no alto curso do Rio Corumbataí-SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A new spiny species of Hypostomus Lacépède (Loricariidae: Hypostominae) from thermal waters, upper rio Paraná basin, central Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Taxonomia molecular e filogeografia de Hypostomus strigaticeps (Teleostei: loricariidae) na bacia do alto rio Paraná

Buscando identificar marcadores populacionais que indiquem supostos mecanismos de isolamento entre as populações, no presente trabalho foram realizadas análises filogenéticas e filogeográficas em populações de Hypostomus strigaticeps, com base em sequências de DNA mitocondrial do gene ATPase 8/6. Um total de 32 exemplares provenientes de 11 populações de quatro sub-bacias: rio Mogi-Guaçu (duas), rio Paranapanema (cinco), rio Tietê (três) e Rio do Peixe (um), tiveram DNA extraído e o gene ATPase 8/6 completamente amplificado (840 pares de base) e sequenciado. As sequências obtidas foram alinhadas com o programa Bioedit, as análises filogenéticas foram realizadas no programa MEGA 5.0 através do método de Neighbor-Joining, Máxima Parcimônia e Minimun-Evolution, com 1000 réplicas de boostrap. Para as análises filogeográficas as sequências foram analisadas no programa TCS. As análises filogenéticas mostraram que a espécie forma uma unidade monofilética composta por duas linhagens: “TG” com representantes das populações dos rios Tietê, Mogi-Guaçu e Rio do Peixe, e “PC” com representantes dos rios Paranapanema e reservatório de Chavantes. A divergência genética da linhagem “TG” é de 0,1% e da linhagem “PP” é de 0,2%, enquanto a divergência genética entre as duas linhagens é de cerca de 1%. Na análise filogeográfica observou-se a existência de seis haplótipos (A-H), sendo o haplótipo A considerado ancestral para as populações analisadas. Apenas os representantes da bacia do Tietê possuem o haplótipo ancestral. Os haplótipos A, B e F possuem a maior frequência (18,51%). Os resultados obtidos para uma população do Mogi-guaçu (Cachoeira de Emas), mostram que estes peixes são muito distantes das demais populações de H. strigaticeps, tanto no ponto de vista filogenético quanto no ponto de vista fitogeográfico... (Resumo completo, clicar acesso eletrônico abaixo)

The cascudos of the genus Hypostomus Lacepede (Ostariophysi: Loricariidae) from the rio Iguacu basin

We reviewed several large collections of the genus Hypostomus from the rio Iguacu basin summing up to 793 specimens mainly from the Laboratorio de Ictiologia do Departamento de Ecologia e Biologia Evolutiva from Universidade Federal de Sao Carlos, from fish collection of Nucleo de Pesquisas em Limnologia, Ictiologia e Aquicultura da Universidade Estadual de Maringa, and from the Museu de Historia Natural do Capao da Imbuia. Hypostomus albopunctatus, H. commersoni, H. derbyi, and H. myersi are redescribed and Hypostomus nigropunctatus is described as a new species. A practical key for identification of Hypostomus species from the rio Iguacu is also provided.