Relação hepatosomática e esplenosomática em peixes teleósteos de cultivo intensivo

The mean values of hepatosomatic relation (HSR), splenosomatic relation (SSR) and relative condition factor (Kn) in Nile tilapia (Oreochromis nilolicus Trewavas, 1983); pacu (Piaractus mesopolamicus Holmberg, 1887); piauçu (Lepori-nus macrocephalus Garavello & Britski, 1988) and tambacu hybrid (P. mesopotamicus male x Colossoma macropomum Cuvier, 1818 female) are described. The experiment was carried out from feefishing farm situated in Franca, São Paulo State, Brazil. Nile tilapia showed the greatest HSR compared to pacu, piauçu and tambacu. Although, in the last three fishes the relation was similar. The SSR between tilapia and piausu was similar, but smaller than observed in pacu and tambacu. Nevertheless, SSR in pacu and tambacu was different. The hepatic weight/body weigth relation and hepatic weight/body length relation presented positive correlation in ali studied fishes. The splenic weight/body weigth relation and splenic weight/body length relation were not significam (P>0.05) in Nile tilapia, pacu and tambacu, but highly significant in piauçu (PO.01).

Fauna parasitária de peixes oriundos de pesque-pagues do município de Franca, São Paulo, Brasil. II. Metazoários

Metazoan fauna from cultivated fishes (N = 433) in two feefishing farm of Franca, State of São Paulo, Brazil, was studied during a period of April 1997 through March 1999. Specimens of piauçú Leporinus macrocephalus Garavello & Britski, 1988 (Anostomidae), pacu Piaractus mesopotamicus Holmberg, 1887 (Characidae), carp Cyprinus carpio Linnaeus, 1758 (Cyprinidae), Tillapia rendalli Boulenger, 1896 (Cichlidae), nile-tilapia Oreochromis niloticus Linnaeus, 1758 (Cichlidae), matrinxã Brycon cephalus Günther, 1869 (Characidae) and tambacu hybrid (male of P. mesopotamicus x female of Colossoma macropomum Cuvier, 1818) were collected. A total of 29.3% was parasitized by monogenean, 9.7% with crustacean (copepodits and adults of Lernaea cyprinacea Linnaeus, 1758 and Argulus sp.) and 1.6% with myxosporean (Henneguya piaractus Martins & Souza, 1997 and Myxobolus colossomatis Moinar & Békési, 1993).The most susceptible species to myxosporean infestation was P. mesopotamicus. L. macrocephalus and P. mesopotamicus that showed a higher susceptibility to Argulus sp infestation. It was not observed significant difference (P > 0.05) in the seasonal variation of L. cyprinacea infection of all species. L. macrocephalus, P. mesopotamicus and tambacu showed a great number of P. pillulare with no significant difference (P > 0.05) between them. Monogenean infections were observed in all examined species, without significant difference (P > 0.05) in the seasonal variation. Nevertheless, occurrence of monogenean was higher in P. mesopotamicus and lower in Nile-tilapia. By the other hand, parasites number collected from P. mesopotamicus was lower in the winter. Copepodits of L. cyprinacea were found in the gills of P. mesopotamicus, tambacu and L. macrocephalus. However, adults of L. cyprinacea were observed only in the P. mesopotamicus and tambacu.

Composição ictiofaunística e estratégias reprodutivas de quatro espécies de peixes nativos da Bacia Hidrográfica Piranhas - Assu, Rio Grande do Norte

This study focuses on the fish fauna composition and reproductive strategies of four native fish species in relation to environmental variables of the Piranhas-Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. Fish and environmental data were collected monthly during the period September 2008 to February 2010, in the Marechal Dutra reservoir and River Acauã a tributary of Piranhas- Assu. The fish were measured, weighed and dissected, and the gonads were removed, weighed and examined macroscopically for identification and determination of gonad maturation stages. The results of this work generated seven articles. The first article is about the fish fauna composition of the Piranhas-Assu hydrographic basin, Rio Grande do Norte. The 602 fish samples captured were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families and 22 species, of which 17 are endemic to the Caatinga ecoregion. The order Characiformes was more representative followed by Perciformes, Siluriformes and Synbranchiformes. The second article is about the length-weight relationship and growth of seven native fish species Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis and Leporinus piau from a semiarid Brazilian reservoir. The third article is about the reproductive aspects of Crenicichla menezesi. Males were larger, heavier and with a slight predominance as compared to females. Four stages of gonadal development were characterized, being immature, maturing, mature and spent. The females reached sexual maturity earlier than males, with an average fecundity of 398 oocytes per batch. The spawning was partial with a long reproductive period. The fourth article deals with the reproductive strategy of Leporinus piau a neotropical freshwater fish in semi-arid region of Brazil. The population of L. piau (n = 211) showed a slight predominance of males (55%), with larger and heavier females. The males matured earlier than the females. This species presented total spawning, with an average fecundity of 55,000 mature oocytes. Rainfall and concentration of dissolved oxygen acted as influential factors during the spawning season. L. piau shows a seasonal reproductive strategy. The fifth article is related to the morphometric-meristic characteristics and reproductive aspects of freshwater sardine, Triportheus angulatus from River Acauã of the Caatinga biome. There was a predominance of larger females, reaching first maturation before males. There was total spawning during the rainy period of the region. The sixth article reports on the reproductive strategy of Psectrogaster rhomboides. The sex ratio was 1M: 1F, with negative allometric growth. Males reached sexual maturity earlier than females Females and males showed four stages of gonadal development and spawned during the rainy season. The fecundity was low and this species presented total spawning. The seventh article reports on the dynamics of territorial behavior of Crenicichla menezesi. Ten agonistic behaviors displayed by the males were observed: frontal and lateral threat, chasing, circular chasing, perpendicular, lateral and mouth attacks, escape, parallel positioning and stationary. The formation of four social groups was observed among males: without interaction; interaction with submission and escape; with frontal and lateral agonistic interactions. In social interactions between males and females, it was observed that the larger males interacted more among themselves and with the larger females. The large male established its territory and the two small males along with the small female were excluded from the other groups. These studies clarified the fish fauna composition and reproductive strategies of four native species Crenicichla menezesi, Leporinus piau, Triportheus angulatus and Psectrogaster rhomboides of the Piranhas- Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil.

O Gênero Cyathus haller: pers. (Agaricales, Basidiomycota) em áreas de caatinga do Nordeste brasileiro

Fungi of the family Nidulariaceae or bird s nest fungi present a vase-shaped basidiomata with the wall surface smooth or striated lengthwise and internal structures resembling small bird eggs in a nest, the peridioles. Among the five genera that comprise the group, the more representative is Cyathus Haller: Pers. The Brazilian Northeast region shows major importance for the world s diversity by containing a Brazilian unique and exclusively phytoecological domain, the Caatinga, which lacks particular attention regarding macrofungi. Although the gradual growth of knowledge in recent years, studies are still insipient in the Caatinga domain. Between their various vegetal formations are the Brejos de Altitude , described as islands with moist perennial vegetation, low soil fertility and annual precipitation of 900 1.300 mm. This study aimed to evaluate the taxonomic richness of Nidulariaceae fungi in Caatinga s areas of Northeastern Brazil, describing and identifying species, as well as expanding the collection of Herbarium UFRN Fungos. For description of Nidulariaceae fungi was followed the proposed by specialized literature in the group. We have found and described 10 species of the genus Cyathus, namely: C. earlei Lloyd, C. gayanus Tul. & C. Tul., C. gracilis H.J. Brodie, C. intermedius (Mont.) Tul. & C. Tul., C. limbatus Tul. & C. Tul., C. montagnei Tul. & C. Tul., C. pallidus Berk. & M.A. Curtis, C. poeppigii Tul. & C. Tul., C. striatus (Huds.) Willd. and C. tríplex Lloyd. Beyond these have been described four new species to science: Cyathus calvescens R. Cruz & Baseia sp. nov., C. hortum R. Cruz & Baseia sp. nov., C. magnomuralis R. Cruz & Baseia sp. nov. and C. parvocinereus R. Cruz & Baseia sp. nov. Two samples were identified only to genus level. No member of Mycocalia J.T. Palmer, Nidula V.S. White, Nidularia Fr. and Crucibulum Tul. & C. Tul. has been found, however the results were extremely valuable for being an unprecedented work in Caatinga, and importante tool for implementation of conservation projects and sustainable utilization of this domain

Diminuição do teor de óxido de crômio (III) usado como marcador externo

A sensibilidade do método espectrofotométrico da s-difenilcarbazida de determinação do crômio permite que esse metal possa ser determinado em teores e em massas de amostras tão pequenas que as concentrações atualmente usadas de óxido de crômio (III) como marcador externo em ensaios biológicos poderiam ser drasticamente diminuídas. Utilizando-se do piauçu (Leporinus macrocephalus) para um estudo sobre o coeficiente de digestibilidade aparente (CDA) da fração protéica, seis níveis de óxido de crômio (III) - 0,01% - 0,02% - 0,03% - 0,05% - 0,1% e 0,2% - foram incorporados em dietas isoprotéica e isoenergética, objetivando-se verificar se o cálculo do CDA seria afetado pela variação do teor do marcador. Os seis tratamentos foram dispostos em um delineamento em blocos inteiramente casualisados, sendo as fezes coletadas durante 16 dias. Verificou-se que os resultados do coeficiente de digestibilidade aparente da fração protéica não apresentaram diferenças estatísticas significativas devidas aos teores incorporados do marcador à ração e aos dias de coleta. Conseqüentemente, e em experimentos dessa natureza, nada impede que seja reduzido o teor de óxido de crômio (III) ao menos até 0,01%: além da economia relativa ao consumo do mesmo e da facilidade na manipulação de menor quantidade de amostras de fezes, o método espectrofotométrico da s-difenilcarbazida permite dosar esse nível (e até menor do que 0,01%) de modo simples e rápido, com precisão e exatidão.

Behavioral response of Nile tilapia to an allopatric predator

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spermatozoa ultrastructure in Sciaenidae and Polynemidae (Teleostei : Perciformes) with some consideration on Percoidei spermatozoa ultrastructure

Spermatozoa ultrastructure was studied in five marines (Paralonchurus brasiliensis, Larimus breviceps, Cynoscion striatus, Micropogonias furnieri, Menticirrhus americanus, Umbrina coroides, Stellifer rastrifer), and one freshwater (Plagioscion squamosissimus) species of Sciaenidae and one species of Polynemidae (Polydactylus virginicus). The investigation revealed that, in all species, spermatozoa display a round head, a nucleus containing highly condensed, filamentous chromatin clusters, no acrosome, a short midpiece with a short cytoplasmic channel, and a flagellum showing the classic axoneme structure (9 + 2) and short irregular lateral fins. In Sciaenidae, the spermatozoa are type II, the flagellar axis is parallel to the nucleus, the lateral nuclear fossa is double arched, the centriolar complex is outside the nuclear fossa, the proximal centriole is anterior and perpendicular to the distal centriole, and no more than ten spherical (marine species) or elongate (freshwater species) mitochondria are observed. Polynemidae spermatozoa are of the intermediate type with the flagellar axis eccentric to the hemi-arc-shaped nucleus, and exhibit no nuclear fossa, the centriolar complex close to the upper nuclear end, the proximal centriole lateral and oblique to the distal centriole, and one large ring-shaped mitocondrion. The data available show that no characteristic is exclusively found in the spermatozoa of members of the Sciaenidae family when compared to other Percoidei with type II spermatozoa. However, three characteristics were exclusively found in Polynemidae: (1) the hemi-arched nucleus; the positioning of the centrioles; and (2) the ring-shaped mitocondrion. The interrelationships between Sciaenidae and Polynemidae as well as between these two families and other Percoidei are herein discussed. (c) 2005 Elsevier Ltd. All rights reserved.

Helminths from Lizards (Reptilia: Squamata) at the Cerrado of Goias State, Brazil

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

Helminths from Seven Species of Lizards (Reptilia: Squamata) at the Cerrado of Mato Grosso do Sul State, Brazil

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

Habitat simplification affects nuclear-follower foraging association among stream fishes

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

Mutilating predation in the Cheirodontinae Odontostilbe pequira (Characiformes: Characidae)

We observed individuals of Odontostilbe pequira, a small characid, approaching and biting individuals of larger-bodied fishes of other species. This observation was made in two clear water headwater streams of the Cuiaba basin, Paraguay River system, located in Nobres, Mato Grosso State, Brazil, which led us to investigate the behavioral interactions of these fish. We characterized behavioral interactions between species by direct underwater observations using snorkelling and video recordings. Additionally, we proceeded diet analyses of O. pequira, obtaining intestinal coefficient and the index of alimentary importance. During underwater observations we checked the relative frequency of attacks by O. pequira on larger fish species. Odontostilbe pequira attacked individually or in large groups, and the anostomid Leporinus friderici was the preferred target prey species, while Prochilodus lineatus was apparently avoided. Our study sustains that O. pequira is omnivorous, with a diet that varies seasonally. It feeds mainly on plants, but also on animal prey, including the scales of small fishes, and, possibly, the mucus and epidermis of larger fish species. We suggest the term "mutilating predation" to describe the latter relationship.

Carbon sources and trophic position of the main species of fishes of Baía River, Paraná River floodplain, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Socio-economic characteristics of the Cachoeira de Emas small-scale fishery in Mogi-Guaçu River, State of São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sport fishing in Cachoeira de Emas in Mogi-Guaçu River, State of São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Taxonomy of Ophiuroidea (Echinonermata) from the continental shelf and slope of the southern and southeastern Brazilian coast

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