Distribuição e ciclo de vida das espécies de peixes mais abundantes da laguna de Marapendi, Rio de Janeiro, Brasil

<abstract language="eng">Monthly sampling from march 1981 to april 1983 using beach seines, cast nets and gill nets indicated six species, Xenomelaniris brasiliensis, Brevoortia pectinata, Geophagus brasiliensis, Gerres aprion, Genidens genidens and Achirus lineatus, as the most abundant fishes in the Marependi Lagoon, Rio de Janeiro, BraziL The species presented a long reproductive period and the recruitment distributed throughout the year. Analysis of the mean catch per unit effort in relation to month, sampling areas, and environmental factors along with analysis of the length frequency distribution by depth strata indicated that the spatial distribution, related to depth and occurrence of submerged aquatic vegetation seem to be the main factors regulating the species distribution. Alteration of the environmental conditions in the lagoon due to the opening of the Marapendi channel in 1984 caused significative modification in the distribution and abundance patterns of the main species. The impact of these alterations in the Marapendi Lagoon fish community has yet to be determined

Larval development of hoplias cf. Lacerdae (Pisces: Erythrinidae) and delayed initial feeding effects

Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days). Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15), were separeted, and fed with Artemia nauplii for 10 days. The point-of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding), was not apparent in this species

Safety of Beauveria bassiana (Bals.) Vuill. to Gallus domesticus L.

Beauveria bassiana, an important insect pathogen was used to evaluate its effect on the feeding, behavior, histology of the digestory system and anatomy of Gallus domesticus. The fungus (strain Unioeste 4) was administrated orally treated with chicken food. Chicken feces were collected, and the birds observed for 28 days. Also, were evaluated the weight of the birds, as well as any sign of intoxication or pathological modification. Tissue samples were withdrawn to test lesions with the optic microscope. There was 100% of survival of the birds, and no behavior alteration or external lesion was found. The test group presented the highest weight gain (1383.9±54.4g). Viable conidia were observed in the feces until 24 h after feeding the fungus, indicating that there was no germination inside the digestory system. No tissue lesion was observed, providing overwhelming evidence for the safety of B. bassiana to non-target organism G. domesticus.<br>Beauveria bassiana é um importe entomopatógeno, sendo avaliado seu efeito sobre a alimentação, comportamento e histologia do sistema digestório de Gallus domesticus. O fungo (isolado Unioeste 4) foi administrado oralmente às aves, misturado à ração. Estas foram observadas por 28 dias e as fezes coletadas diariamente para análise. Também foi avaliado o peso das aves, bem como sinais de intoxicação ou modificação patológica. Amostras teciduais foram retiradas para verificar lesões com o microscópico óptico. Houve sobrevivência de 100% das aves avaliadas e nenhuma alteração comportamental ou lesão externa durante o experimento. O grupo teste apresentou o maior ganho de peso (1383,9±54,4g), sendo mais acentuado a partir da segunda semana. Observou-se a presença de conídios viáveis nas fezes somente até 24 horas após a ingestão do fungo, indicando que não houve germinação nas aves. Nenhuma lesão tecidual foi verificada, de forma que B. bassiana mostrou-se seguro para o organismo não-alvo G. domesticus