Molecular systematic and historical biogeography of the armored Neotropical catfishes Hypoptopomatinae and Neoplecostominae (Siluriformes: Loricariidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Localization of 18S ribosomal genes in suckermouth armoured catfishes Loricariidae (Teleostei, Siluriformes) with discussion on the Ag-NOR evolution

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

CYTOGENETIC AND DNA CONTENT STUDIES OF ARMORED CATFISHES OF THE GENUS CORYDORAS (PISCES, SILURIFORMES, CALLICHTHYIDAE) FROM THE SOUTHEAST COAST OF BRAZIL

Cytogenetic and DNA content studies were done on six nominal species of Corydoras from the southeast coast of Brazil. The data show that several nominal species present local populations with differences in karyotype or DNA content. There are at least two groups of Corydoras species with similar karyotypic structure in this region: the first composed by C. ehrhardti, C. nattereri and C. paleatus and the second composed of C. barbatus, C. macropterus and C. prionotos. These two groups of species are probably not derived directly from the same ancestral line. The speciation process of Corydoras species from the southeastern coast of Brazil is discussed.

Frequency and gravity of human envenomations caused by marine catfish (suborder siluroidei): a clinical and epidemiological study

Introduction and objectives: Catfish occur in marine and freshwater environments worldwide. They have three serrated venomous bony stings in the dorsal and pectoral fins that are used for defence against predators and are refilled by glandular tissues under the epithelium. However, some catfishes do not have poisonous glands next to the sting and cause traumatic wounds without poisoning. The objective of this study was to provide data for, and comment on, the epidemiological and clinical problems caused by marine catfish.Patients and methods: the authors have observed, followed and documented 127 injuries caused by marine catfish stings during different phases of the envenoming over a time period of 8 years at three points along the Western Atlantic Ocean coast.Results: the patients presented intense pain during the acute phase of envenoming and complications, such as bacterial and fungi infections and retention of bony fragments, in the later phase. Immersion of the affected extremity in hot water was used in about 20% of cases with excellent results.Discussion: Injuries caused by marine catfish are common (about 20% of injuries caused by marine animals in a series of more than 700 injuries recorded by the author) and cause intense pain and later complications. Immersion of the affected extremity in hot water results in improvement in the acute phase, but does not prevent the appearance of secondary infection or foreign body reactions. (c) 2006 Elsevier Ltd. All rights reserved.

Competition and phylogeny determine community structure in Mullerian co-mimics

Until recently, the study of negative and antagonistic interactions (for example, competition and predation) has dominated our understanding of community structure, maintenance and assembly(1). Nevertheless, a recent theoretical model suggests that positive interactions (for example, mutualisms) may counterbalance competition, facilitating long-term coexistence even among ecologically undifferentiated species(2). Mullerian mimics are mutualists that share the costs of predator education(3) and are therefore ideally suited for the investigation of positive and negative interactions in community dynamics. The sole empirical test of this model in a Mullerian mimetic community supports the prediction that positive interactions outweigh the negative effects of spatial overlap(4) (without quantifying resource acquisition). Understanding the role of trophic niche partitioning in facilitating the evolution and stability of Mullerian mimetic communities is now of critical importance, but has yet to be formally investigated. Here we show that resource partitioning and phylogeny determine community structure and outweigh the positive effects of Mullerian mimicry in a species-rich group of neotropical catfishes. From multiple, independent reproductively isolated allopatric communities displaying convergently evolved colour patterns, 92% consist of species that do not compete for resources. Significant differences in phylogenetically conserved traits (snout morphology and body size) were consistently linked to trait-specific resource acquisition. Thus, we report the first evidence, to our knowledge, that competition for trophic resources and phylogeny are pivotal factors in the stable evolution of Mullerian mimicry rings. More generally, our work demonstrates that competition for resources is likely to have a dominant role in the structuring of communities that are simultaneously subject to the effects of both positive and negative interactions.

Genetic variability of two populations of Pseudoplatystoma reticulatum from the Upper Paraguay River Basin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Molecular systematics of the armored neotropical catfish subfamily Neoplecostominae (Siluriformes: Loricariidae)

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

Development and characterization of microsatellite loci in Phractocephalus hemioliopterus (Siluriformes: Pimelodidae) and their cross-species amplification in six related species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sperm of Doradidae (Teleostei: Siluriformes)

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

Ingestion of catfish by freshwater stingray: possible mistake or inexperience

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Neoplecostomus (Teleostei : Loricariidae) from the upper Rio Parana basin, Brazil, with description of three new species

Neoplecostomus paranensis was the only Neoplecostomus species known from the upper Rio Parana basin, and it was diagnosed from its congeners mainly by the absence or reduction of the adipose fin. In this study we describe three new Neoplecostomus species. All of them are promptly differentiated from N. paranensis by having a well-developed adipose fin. Furthermore, the new species are differentiated from congeners by morphometric and meristic traits, in addition to color pattern. Neoplecostomus paranensis is redescribed. We also provide an identification key to all Neoplecostomus species.

Ecology of a stream from upper Paraná River basin inhabited by Aspidoras fuscoguttatus Nijssen & Isbrüker, 1976 (Siluriformes, Callichthyidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Testing the ecomorphological hypothesis in a headwater riffles fish assemblage of the rio São Francisco, southeastern 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)