Population structure, feeding and reproductive aspects of Serrapinnus heterodon (Characidae, Cheirodontinae) in a Mogi Guaçu reservoir (SP), upper Paraná River basin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A NEW SPECIES of ISCHNOCNEMA (ANURA) FROM THE SAO FRANCISCO BASIN KARST REGION, BRAZIL

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

Biological aspects of Schizodon nasutus Kner, 1858 (Characiformes, Anostomidae) in the low Sorocaba river basin, São Paulo state, Brazil

Four biological aspects of Schizodon nasutus in the low Sorocaba river basin, São Paulo, Brazil were analysed. These were accomplished during the year seasons. The fish diet and the feeding activity were investigated by studying the repletion index, which showed no significant differences between seasons. The food items analysed by frequency of occurrence and dominance showed a predominance of vegetable items in the diet. The reproduction, analysed by using the gonadosomatic index, indicated that the reproductive period occurs during the summer period when temperatures are higher and rainfalls are more intense. The amount of accumulated fat and condition factor varied according to reproduction, especially for females.

CONDITION of Hoplias aff. malabaricus (BLOCH, 1794) IN TWO COASTAL STREAMS of ITANHAEM RIVER BASIN, BRAZIL

The main purpose of this research was to measure the condition of the fish species Hoplias aff. malabaricus collected in Aguapeu River (black waters) and Branco River (white waters), which belong to Itanhaem River basin, a coastal watershed in São Paulo state, Brazil. Individuals of Hoplias aff. malabaricus were sampled by using gill nets, monthly from March 2001 to February 2002. The Condition Factor was obtained through the length-weight relationship, assuming that the higher the mass for a given length, the better the condition of the fish. The Condition Factor was compared among fishes from both rivers, resulting that Branco River individuals have significantly lower condition. Limnological aspects were studied from May 2001 to November 2002 and some show significant differences between Aguapeu River and Branco River. These were salinity, do and total organic N, which the higher values being observed in Branco River propably due to estuarine waters influence. However, the lower condition of the Branco River fishes should also be an effect of a disturbance due to the sand mining in this river, since this activity cause important alterations to the environment, affecting the whole biota, included aquatic macrophytes, invertebrates and fishes.

Reproductive strategies of two Curimatidae species in a Mogi Guacu impoundment, upper Parana River basin, São Paulo, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fish, Passa Cinco stream, Corumbatai River basin, state of São Paulo, Brazil.

The fishes of the present study were collected in Passa Cinco stream, a main river of Corumbatai river basin, Tiete drainage. Five sites were selected in that stream, downstream from headwater to its mouth, and six samplings were performed using the following fishery equipment: a sieve, electric fishery equipment, gill nets and fish-traps. 5082 individuals, 62 species, 18 families and 6 orders were captured. The orders Characiformes and Siluriformes were the most representative and the families Characidae and Loricariidae presented the largest in number of species.

Mercury Redox Chemistry in the Negro River Basin, Amazon: The Role of Organic Matter and Solar Light

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

Metal fluxes at the sediment-water interface in rivers in the Turvo/Grande drainage basin, So Paulo State, Brazil

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

Major Aspects of the Mercury Cycle in the Negro River Basin, Amazon

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

Structure and composition of the stream ichthyofauna of four tributary rivers of the upper Rio Parana basin, Brazil

The ichthyofauna of 24 stretches of streams, all of 100 m length and of fifth or lower order and most of second and third order, were sampled along four left bank tributaries (Rio do Peixe, Rio Aguapei, Rio Sao Jose dos Dourados, lower Rio Tiete of the main channel of the Rio Parana in the state of São Paulo, southeastern Brazil. Sampling of the fish fauna at each of the six sites in the four basins incorporated a standardized fish collecting methodology and a standardized documentation of environmental data serving as the basis for a comparative analysis of the collecting locations. The 8,189 fish specimens collected represented six orders, 18 families, 42 genera, and 56 species, with a total biomass of 28.8 kg. Approximately 52% of the collected species were characiforms, 28% siluriforms, 9% gymnotiforms, 5% cyprinodontiforms, 4% perciforms, and 2% synbranchiforms. The most abundant of the species were the characiforms Astyanax altiparanae (15% of total) and Knodus moenkhausii (12% of total). The two species with the largest overall biomasses were A. altiparanae (34% of total biomass) and the siluriform Hypostomus sp. (8% of total biomass). Analysis of the trophic structure of the studied ichthyofauna indicated that the 10 numerically dominant species across the 24 sampled streams can be grouped into five guilds that are in decreasing order of numerical importance: omnivores, insectivores, insectivores/invertivores, periphytivores, and algivores. Species richness in the sampled stream stretches varied from six to 20 species with an average richness of 14. The species richness estimated by extrapolation for all 24 sampled stream stretches was 67 species. The Characidae are predominant among the collected specimens with approximately 50% of both individuals and biomass, a fact hypothesized to be a function of several attributes typical of the family. Six of the 56 collected species were new to science and six other species are of indefinite taxonomic status and require further analysis in order to determine their identity.

Astyanax ajuricaba: a new species from the Amazon basin in Brazil (Characiformes: Characidae)

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

Revalidação de Astyanax rupununi Fowler, 1914 (Teleostei, Characidae) e descrição de duas espécies novas para o gênero

A. rupununi Fowler, 1914, considerada sinônimo de A. bimaculatus (Linnaeus) por Eigenmann (1921) é revalidada e duas espécies novas são descritas: A. clavitaeniatus, do alto rio Branco, Roraima, Brasil, e A. siapae, da bacia do Casiquiare-Orinoco, Estados Amazonas e Apure, Venezuela. Essas três espécies apresentam o mesmo padrão básico de coloração: mancha umeral negra horizontalmente ovalada, mancha negra no pedúnculo caudal estendida à extremidade dos raios caudais medianos, duas barras verticais marrons (a primeira cruzando a mancha umeral e a segunda situada 23 escamas atrás) e característica faixa lateral negra em forma de clava. Os caracteres que distinguem as três espécies são discutidos e é apresentada uma chave de identificação para as três espécies.

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.

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)

A new species of Moenkhausia from the rio Amazonas and rio Orinoco basins (Characiformes: Characidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)