Population growth and development of two species of Cladocera, Moina micrura and Diaphanosoma birgei, in laboratory

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cultivo de Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) em laboratório utilizando meio CHU12 e de macrófita com NPK

Two different culture media, namely CHU12 and inorganic fertilizer NPK (20-5-20) associated with macrophyte (Eichhornia crassipes) extract, were used to evaluate the development of A. gracilis. Growth rate, development, nutritional value and medium water quality were analyzed. A. gracilis in macrophyte+NPK medium had mean cell density (333x10(5) cells/mL) higher than medium CHU12 (302x10(5) cells/mL). Protein rate (12.52% PS), dry weight (397x10(7) pg/cell) and ashes (4.08x10(7) pg/cell) in A. gracilis was higher (p<0.05) than medium macrophyte+NPK. on the other hand, lipids, carbohydrates and fibers had the same rate (p>0.05) in both media. When hydrological variables in the culture medium of A. gracilis are taken into account, dissolved oxygen and free CO2 alone failed to have any significant difference (p>0.05) between the media employed. A. gracilis in the macrophyte+NPK medium had the same nutritional rate as the commercial medium CHU12, with excellent results for alga growth. Macrophyte medium may be used for large scale alga culture in the feed of fish larvae.

Eutrofização e qualidade da água na piscicultura: consequências e recomendações

The eutrophication (cultural or anthropogenic) is induced by man and can have different origins, such as domestic sewage, industrial and agricultural activities, including the effluent still breeding systems of aquatic organisms. The expansion of aquaculture, with production of biomass and increase of nutrients in water may cause acceleration of productivity of algae, changing the ecology of aquatic systems. In addition, these waste water may present a risk to health through the transfer of pathogens from manure, plant residues, composted material, among others that are major sources of organic waste in some farming systems. Depending on the trophic level of fish ponds, which are dynamic environments, different planktonic species with short reproductive cycle and adapted to the changes contained in these systems can appear in high abundance. Water quality in the systems for raising fish is related to several factors, such as water source, management (liming, fertilizing, cleaning), cultivated species and quantity and composition of exogenous food. In order to minimize environmental impacts, there are techniques to improve the quality of water in fish farming systems and thus satisfactory answers can be obtained through the application of management practices. This paper aims to review the subject that deals with changes in water quality resulting from the activity of freshwater fish culture in Brazil. Search also recommend techniques of good management practices to minimize the impact generated by the activity.

Levantamento florístico das comunidades de macroalgas da bacia do Rio das Pedras, região centro-sul do estado do Paraná, sul do Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ecological distribution of stream macroalgae in different spatial scales using taxonomic and morphological groups

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Basicladia emedii (Cladophorales, Chlorophyta): a new freshwater epilithic species from Brazil

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

Utilización de columnas verticales de filtración de manta y arena como pre-tratamiento de un sistema de filtración lenta

Slow sand filtration is an efficient water treatment technique used for treating surface water with relatively low levels of contamination. Despite the slow sand filtration at pathogen, algae and cyanobacteria removal efficiency, it has some restrictions in relation to the required area for slow filters, and the cleaning activities for the filters and the stone pre-filters when used in the treatment. This research evaluated during 120 days the use of non woven & sand pre-filtration columns as part of a slow filtration process for the apparent color, turbidity, algae, cyanobacteria, phytoflagellates and diatomaceous. The columns shown an efficient removal of the monitored parameters and demonstrated as a vantage their faster and easier cleaning process and less awkward than the required to the stone pre-filters. The turbidity removal efficiency increased progressively during the experiment, especially after the first 35 days of the start; the apparent color removal by the pre-filtration columns was of 85%, and working together with the polishing of activated carbon columns was up to 95; the diatomaceous, phytoflagellates, algae and cyanobacteria removal by the columns achieve a weekly average of 95%, its recommended to use filtration rates lower to 1,5m(3)/m(2)/d.

Diagnosis of clinical bovine mastitis by fine needle aspiration followed by staining and scanning electron microscopy in a Prototheca zopfii outbreak

Biopsy by fine needle aspiration together with microbiological examination and scanning electron microscopy were evaluated in diagnosis of clinical bovine mastitis in a Prototheca zopfii outbreak. Fine needle aspiration was performed in 21 mammary quarters from ten Holstein cows presenting clinical mastitis caused by P. zopfii. The algae were previously identified in the microbiological examination of milk collected from these cows. Material aspirated from these 21 mammary glands was submitted to cytological staining (Gram, Giemsa and/or Shor staining). Fine needle aspiration enabled cytological identification of the algae in these 21 mammary glands, from which P. zopfii was isolated in the milk. Simultaneously, five mammary fragments collected by fine needle aspiration from these 21 mammary glands presenting clinical mastitis were also submitted to microbiological examination. P. zopfii was also isolated from these five fragments. Scanning electron microscopy technique also identified three of these five P. zopfii strains isolated from mammary fragments collected by cytological aspiration. These results suggest that fine needle aspiration may be an alternative method for the diagnosis of clinical mastitis.

Phenotypic and genotypic characterization of Prototheca zopfii in a dog with enteric signs

This is a case report of enteric protothecosis caused by Prototheca zopfii in an eight-year-old male mixed breed dog with a history of chronic bloody diarrhea, loss of appetite and weight loss. Algae were isolated from rectal scrapings in defibrinated sheep blood agar and dextrose Sabouraud agar. Cytological evaluation showed the presence of globular and cylindrical organisms with a defined capsule and variable number of endospores, characteristic of the genus Prototheca, in the rectum of the animal. Scanning electron microscopy of P. zopfii strains at different development stages confirmed the diagnosis of algal infection. Molecular identification using a conserved 18S rDNA gene sequence determined that the strain belonged to genotype 2. This report describes success on treatment of canine protothecosis, diagnosed based on clinical, cytological, microbiological, scanning electron microscopy and genotypical findings. (c) 2009 Elsevier Ltd. All rights reserved.

In vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on Prototheca zopfii strains isolated from bovine milk

Prototheca zopfii has been considered one of the most important causes of environmental mastitis in Brazil. These algae are refractory to conventional therapy and cause great damage to the mammary gland. The present study evaluated the in vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on 27 P. zopfii strains isolated from the milk of cattle. Low concentrations of sodium hypochlorite (0.0390625-0.15625%) and iodine (0.15625-0.625%) were effective against the isolates. These antiseptics may be recommended for hygiene routines, pre and postdipping and cauterization of bovine mammary glands infected by P. zopfii. (C) 2009 Elsevier Ltd. All rights reserved.

Alternative calcium source effects on commercial egg production and quality

This study aimed at verifying the possibility of replacing calcitic limestone by marine calcium in the diet of layers. A total number of 321 Hi-sex hens, with 40 weeks of age at the beginning of the experiment, was used. A completely randomized experimental design was applied, with 5 treatments (0, 15, 30, 45, and 60 % of calcitic limestone replacement by marine calcium source) and eight replicates of eight birds each. Treatments significantly affected specific gravity (p<0.05), with the inclusion of 60% marine calcium (T5) presenting the worst result as compared to T1, which included only calcitic limestone as calcium source. It was concluded that marine calcium can replace up to 45% of calcitic limestone with no effects on performance or egg quality.

Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

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

Larval development of Epialtus bituberculatus H. Milne Edwards, 1834 (Crustacea : Decapoda : Brachyura : Majidae) with comments on majid larvae from the southwestern Atlantic

The larval development of the spider crab Epialtus bituberculatus H. Milne Edwards which Lives on rocky shores with algae such as Sargassum and Hypneia, is described. Larvae were obtained from ovigerous females collected in Ubatuba, State of São Paulo, Brazil. Rearing was carried out at 24 +/- 1 degreesC, with an average salinity of 35 parts per thousand. Larval development consists of two zoeal stages and one megalopa. Zoeal development was completed in 9.5 days. Analysis indicated that zoeae of E. bituberculatus are very similar to those of E. brasiliensis Dana and Acanthonyx scutiformis (Dana). Differences noted between these species pertain to the setation of the carapace, maxillule and second maxilliped. The main morphological features useful for identification are presented together with a summary of features that characterize larvae of majid subfamilies in Brazil. A key for the identification of southwestern Atlantic majid zoeae to the family level is provided.

Phytoplankton composition, dominance and abundance as indicators of environmental compartmentalization in Jurumirim Reservoir (Paranapanema River), São Paulo, Brazil

Patterns in the spatial and temporal composition, dominance and abundance of the phytoplankton community of the Jurumirim Reservoir (Brazil) were studied during one year at ten different sampling stations. The main phytoplankton associations were characterized by diatoms and blue-green algae, in distinctive patterns of dominance. The main species were Microcystis aeruginosa Kuetz, Anabaena circinalis Rabenhorst, A. spiroides Kleb., A. solitaria Kleb., Aulacoseira cf. italica Grunow and A. granulata (Ehr.) Simon. A high growth of Aulacoseira was observed in the upstream zones of the reservoir in spring, at the beginning of the seasonal rainy period. This growth was a response to increased flow rates and input of fresh nutrients by the main feeder rivers. A high concentration of blue-green algae, especially Anabaena circinalis and A. spiroides, was observed in winter (dry season) in the lacustrine part of the reservoir, towards the dam. These algae benefitted from the longer water retention times and greater internal circulation of nutrients in the absence of a thermocline at this time of the year. Among the Cyanophyceae, there was an alternation between M. aeruginosa, more abundant in summer, and Anabaena, dominant in autumn and winter. A conspicuous growth of Anabaena occurred in a diverticle of the reservoir, sheltered from the main advective processes that predominate in the central channel. Higher phytoplankton diversity was associated with the contact zone between riverine and lacustrine systems.

The effect of the land use on phytoplankton assemblages of a Cerrado stream (Brazil)

OBJETIVO: Nosso objetivo foi investigar se o uso do solo do ambiente terrestre adjacente influencia a estrutura das assembleias fitoplanctônicas (composição, riqueza, diversidade e abundância) e biomassa (clorofila-a) em um riacho de Cerrado durante diferentes períodos do ano. MÉTODOS: Os trabalhos de campo foram realizados trimestralmente durante dois anos. RESULTADOS: As variáveis físico-químicas que melhor indicaram as diferenças nas condições da água foram condutividade, oxigênio dissolvido e transparência. Também houve um notável aumento na concentração de nitrogênio, fósforo e material em suspensão na água durante o verão devido aos efeitos da pluviosidade. As assembleias fitoplanctônicas foram compostas por 64 espécies. Cryptophyceae foi o grupo mais abundante, seguido por Bacillariophyceae. Para ambos os anos, a riqueza e a diversidade foram maiores durante a primavera e no outono, enquanto que a abundância do fitoplâncton e a concentração de clorofila-a foram mais elevados durante o outono e verão. A análise de agrupamento e a analise de correspondência canônica mostraram que a sazonalidade e o uso do solo são fatores importantes na estruturação das assembleias ao longo do ano. As alterações nas assembleias fitoplanctônicas ocorreram provavelmente em função da variação na intensidade e freqüência da mistura da água e da entrada de nutrientes oriundo do sistema terrestre adjacente para o aquático. CONCLUSÃO: A estrutura das assembleias fitoplanctônicas mostrou ser altamente influenciada pelo uso do solo, corroborando com a hipótese inicial do trabalho.