Effect of two green algae species (Chlorella sp. & Scenedesmus obliquus) enriched with B group vitamins on food chain of Rutilus frisii kutum (Kamensky, 1901) fry

The Effect of two freshwater green algae species Chlorella sp. & Scenedesmus obliquus enriched (from the beginning of culture and after 96 hours) with different dosages of B group vitamins (0, 0.5, 1, and 2 ml of enriching solution per each liter of algae medium) on fecundity of Daphnia magna and growth of Rutilus frisii kutum fry were investigated in a research from spring, 2008 to autumn, 2009. First, each of the green algae species were cultured purely and massively in the Zander (Z-8+N) medium and then the nutritional value (the amount of protein, lipid, and carbohydrate) of enriched algae were meausered. In this study, enriching of Chlorella sp. & S. obliquus with a suitable mix of B group vitamins significantly improved their nutritive value. So the highest amount of nutritional value of Chlorella sp. was obtained because of enriching with dosage 0.5 ml.l-1 (366.654Kcal) and for Scenedesmus obliquus with dosage of 1 ml.l-1 (376.95Kcal). The acquired amount from control group showed an increase of respectively 42% and 11%. According to the results, increased dosages of enriching solution caused Daphnia fecundity to increase (at both stages : enrichment from the beginning of culture and after 96 hours). So the highest average of D. magna reproduction rate was obtained through being fed with Chlorella sp. and S. obliquus enriched with dosage of 2 ml enriching solution per liter of algae medium. The average fecundity of D. magna fed with Chlorella sp. enriched with dosage of 2 ml.l-1 enriching solution from the beginning of culture and after 96 hours was obtained respectively 2.128 ± 0.375 and 2.1 ± 0.69 and the average fecundity of D. magna fed with S. obliquus enriched with dosage of 2 ml enriching solution from the beginning of culture and after 96 hours was obtained respectively 2.128 ± 0.375 and 2.1 ± 0.69 which showed respectively an increase of 61 ٪, 91٪, 77 ٪, and 83٪ in proportion to the acquired amount from control group. When enriching solution was added to either algae culture medium from the beginning of culture, showed statistically significant differences (P<0.05) between dosages of 0 and 2 ml.l-1, 1 and 2 ml.l-1, and 0.5 and 2 ml enriching solution per each liter of Chlorella sp. culture medium and between dosages of 0 and 1 ml.l-1, and 0 and 2 ml enriching solution per each liter of S. obliquus culture medium. The highest average of body weight gain percentage and specific growth rate of kutum fry was obtained respectively 21.19%, 26.63%, 1.92, and 2.34 from the beginning of culture and after 96 hours with dosage of 1 ml B group vitamins per each liter of Chlorella sp. culture medium, which showed respectively an increase of 50%, 70%, 46%, and 62% in proportion to the acquired amount from control group. In the cases which Chlorella sp. were grown in the medium containing vitamin, from point of view of the average percentage of weight and specific growth rate of kutum fry significant differences were observed on the basis of the result of One-way ANOVA between dosages of 0 and 1, 1 and 2 , 0.5 and 1 ml B group vitamins per each liter. The highest average of body weight gain percentage and specific growth rate of kutum fry was obtained respectively 32.02%, 29.42%, 2.78, and 2.34 from the beginning of culture and after 96 hours with dosage of 2 ml B group vitamins per each liter of S. obliquus culture medium, which showed respectively an increase of 32%, 19%, 28%, and 17% in proportion to the acquired amount from control group. In the cases which S. obliquus were grown in the medium containing vitamin, from point of view of the average percentage of weight and specific growth rate of kutum fry significant differences were observed on the basis of the result of One-way ANOVA between dosages of 0 and 1, 0 and 2. According to the results of the present research we can say that considerable enhancement in the quality of the food of D. magna can be made by manipulation of the nutritional value of fresh water unicellular green algae with suitable mixture of B group vitamins, so that both the fecundity of D. magna will increase and the nutritional requirements of the kutum fry will be filled in this way.

Report on fresh-water copepoda from Panama, with descriptions of new species

These collections were made by Meek and Hildebrand, in connection with their work on fishes in the seasons of 1911 and 1912, by Goldman in 1912, and by Marsh who was present in Panama for four weeks in 1912 for the express purpose of making such collections. Most of the collections were made within the limits of the Canal Zone. A few collections were made in eastern Colombia, some on Rio Bayana and its tributaries, some on the Chagres and Trinidad outside the Zone and some in the neighborhood of Chorrera and of old Panama... (Document has 33 pages)

Control of bacterial disease in small scale fresh-water aquaculture: Project R0754. Project completion report December 1998 - May 1999

The work presented here represents an 18-month study to examine the relationship between environmental conditions, bacterial load in the water and bacteria levels in tissue macrophages of a range of clinically healthy freshwater fish species, farmed in a range of culture systems in Thailand and Vietnam. Preliminary assessment was made of the clinical significance of the macrophage bacterial load. The aim of this work was to improve production in fresh-water aquaculture through the control of clinical bacterial disease and subclinical infection, and to identify management practices most effective in promoting fish health. [PDF contains 37 pages]

Fresh and brackish water shrimps of economic importance in the Niger Delta

In the author’s opinion, extremely little is known of fresh and brackish water species, i.e. those supporting the traditional artisanal fisheries and most likely to include suitable candidates for aquaculture. The immediate purpose of this paper is to document the species which are encountered in artisanal fisheries, give available background information on them relevant to fisheries and aquaculture work, and to provide a means for their identification in the field by nonspecialists. Scope of Coverage the "Niger Delta" in the title reflects the geographical area of the author’s personal experience. For purposes of identification, the scope of the paper is West African for brackish species, and Nigerian for freshwater species

Pre-packaged fresh fish - Searching for quality descriptive criteria

32 Proben verpackten Frischfischs in Selbstbedienungspackungen, 16 Seelachs- und 16 Rotbarschproben aus deutschen Supermärkten wurden mit physikalischen, chemischen, mikrobiellen und sensorischen Methoden untersucht. Ziel der Untersuchung war dieWertung von Untersuchungsmethoden zur Qualitätsbestimmung. Es zeigte sich, daß neben der sensorischen Beurteilung die Bestimmung des TVB-N geeignet ist, die Qualität dieser Produkte zu beurteilen.

An annotated bibliography of research on coarse and salmonid fish (excluding salmon and trout) found in fresh water in Scotland

The authors provide an extensive annotated bibliography to a full list of species occurring in Scotland, to highlight what is known about them and to indicate potential areas for further research. The list of references brings together published research papers and numerous unpublished theses and reports, including experimental and laboratory studies conducted in Scotland, although some may not have unique application to the fish fauna in Scottish waters. There has been no attempt to include references that are made incidentally in the general literature intended for naturalists.

The environmental requirements of salmon and trout in fresh water

This article is a summary for the general reader, rather than an in-depth review, and attempts to define, as quantitatively as possible, the habitat requirements of salmon and trout and then to relate them to the main ways in which man's activity can influence the survival and growth of these fishes. Frequent text references to an extensive body of published work have been avoided, although a selective bibliography has been included which lists some of the main work upon which the text depends. This article deals only with the freshwater part of the life cycle, and the coverage has some bias towards England and Wales.

Limnology in Sicily: A history of fresh waters surrounded by the sea

The aim of this short article is to trace the history of limnology in Sicily, from the end of the last century up to the present, and pay a little homage to a scientist to whom limnology is deeply indebted: G.E. Hutchinson. Due to its insular and climatic conditions, Sicily is characterised by a drainage network formed by numerous short, torrent-like rivers, and by a few small, natural lakes. The geological characteristics of the island strongly condition the quality of these small waterbodies which generally have surface areas of less than 0.2 km super(2). The earliest observations on Sicilian lentic waters go back more than a century; in particular, at the end of the 19th century, some of the issues regarding the natural lakes had already been brought into focus. Subsequent studies on natural waterbodies concentrated on the geomorphology of landslide lakes or lakes created by the dissolution of the gypsum tableland. However, many of the waterbodies no longer exist because of land reclamation which took place up to the first half of the 1950s. During the last 35 years, there has been a notable increase in limnological publications. In addition, these studies show a more careful and integrated approach to the limnological aspects of waterbodies, compared with the early studies.

Subspecies, morphs and clines in the amphipod Gammarus duebeni from fresh and saline waters

The nature and extent of morphological variation within populations of Gammarus duebeni are examined. The exceptional tolerance of G. duebeni to salinities that encompass three orders of magnitude was known in the 19th Century, and has attracted considerable attention from physiologists and ecologists in the 20th Century, including the likelihood that populations in freshwater are distinct from those living in more saline environments. It is concluded that gradual evolution into discrete and readily distinguished subspecies is currently underway, eventually producing several new species in freshwater and saline habitats.

Taking a systems-oriented view of phosphorous enrichment in fresh waters

Eutrophication of fresh waters through anthropogenic enrichment by phosphorus is a global problem. The role of phosphorus enrichment in the formation of blooms of toxic blue-green algae (Cyanobacteria) in fresh waters is well established and of considerable concern in terms of human and animal health, loss of water resources and amenities, threats to fish stocks, and aesthetic considerations. Cultural eutrophication also poses threats to the ecosystem balance in fresh waters, with implications for wildlife. This article examines phosphorus enrichment in fresh waters from a systems perspective, and explores systems solutions that may be helpful in the development of more sustainable policies.

The phytoplankton of an enriched, soft-water lakel subject to intermittent hydraulic flushing (Grasmere, English Lake District)

This paper describes some characteristic features of the phytoplankton of Grasmere, one of the smaller of the principal lakes of the English Lake District, and attempts to relate these to distinctive physical and chemical properties of the lake. Quantitative data presented herein are derived from 5-m vertical column samples, collected with a flexible polyethylene hose close to the deepest point of Grasmere, generally at intervals of 14 days ( 7 days from 1972 to 1978, inclusive). The study concludes that although Grasmere has been subject to increased phosphorus-loading and has quickly developed many features associated with eutrophication, the composition of its plankton has retained the characteristics of a mesotrophic, soft-water lake: a vernal diatom maximum, generally dominated by Asterionella, is followed by summer growths of nanoplanktonic species, of various colonial Chlorophyceae, before a substantial return to Asterionella-dominance in the autumn.

Actinomycetes and actinophage in fresh water

Actinomycetes are a group of micro-organisms which lie, in classification, half-way between the fungi and the bacteria. They may be isolated from the plating of leaf washings, water samples and mud dilutions on to nutrient agar (with incorporated actidione to eliminate fungi). The predominant genus varied with the source of the sample. An attempt was also made to isolate the phages of some Actinomycetes. A search was made in the typical environments of the host, for the virus. In this way actinophage were also isolated; and shown to be capable of being transmitted from one host strain to another host strain within 1 sp or from one host to another within 1 genus; i.e. polyvalent.

Petroleum hydrocarbons in fresh waters: a preliminary desk study and bibliography

A literature survey was carried out into the effects of petroleum hydrocarbons in freshwater, from the toxicity, biodegradability and concentration aspects. It was supplemented by a selective search on hydrocarbons in the marine environment for comparison. The aim was to determine the major inputs of these hydrocarbons, their accumulation, effects and fate in freshwaters. The search was confined to the period 1965-1978. The bibliography contains 390 references, divided by subject.

The diversity and ecological role of protozoa in fresh waters

Protozoa feed on and regulate the abundance of most types of aquatic microorganisms, and they are an integral part of all aquatic microbial food webs. Being so small, aerobic protozoa thrive at low oxygen tensions, where they feed (largely unaffected by metazoan grazing) on the abundance of other microorganisms. In anaerobic environments, they are the only phagotrophic organisms, and they live in unique symbiotic consortia with methanogens, sulphate reducers and non-sulphur purple bacteria. The number of extant species of protozoa may be quite modest (the global number of ciliate species is estimated at 3000), and most of them probably have cosmopolitan distributions. This will undoubtedly make it easier to carry out further tasks, e.g. understanding the role of protozoan species diversity in the natural environment.