Chemical analyses of 21 species of dried aquatic plants indicate that they contain the sufficient quantities of nutrients to be considered as livestock feedstuffs (Linn et al., 1975). Although considerable variations are among 21 species, 14 species contain more than 10% protein and all species contain less than 30% crude fiber. Mixed aquatic plant species (approximately 50% Myriopbyllus, 30% Ceratopbyllum, 10% Potamogeton, 5% Vallisneria and 5% unknown) have been ensiled with the organic acids (acetic, formic, propionic), corn or alfalfa. After 47 days of fermentation the silages have had pH values above 4.5 and lactic acid values below 0.4% of the dry matter. Acoording to Linn et al. (1975), acid-treated aquatic plant and alfalfa silages are higher in crude protein, indicating that acid additions decrease protein loss during fermentation.

To facilitate fish cultivation in rural areas of the Neotropics, the potential of cosmopolitan and locally available aquatic macrophytes from northern Colombia (Lemna minor, Spirodela polyrhiza, Azolla filiculoides and Eichhornia crassipes) as alternative fish feed are studied by Cruz et al. (2011). Considering the importance of fermentation in improving nutritional value of non-conventional feeds, fermentation properties and effects of anaerobic fermentation on the nutritional quality of the selected aquatic plants are evaluated. Although the fermentability coefficients (FC) of the selected aquatic macrophytes reveal hardly fermentable materials (FC < 35), the use of bacteria inoculants (Lactobacillus plantarum) and molasses (150 g kg^-1) results in good silage quality. Lactic acid fermentation positively affects the nutritional quality of the selected plants, reducing the concentration of some antinutritional substances (trypsin inhibitor, phytates, tannins and more) and crude fibre content.

According to Cruz et al. (2011), an amino acid profile of the raw macrophytes is sufficient to amino acid requirements of tropical fish Nile tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus). The amino acid profile is similar in the raw plants and represented by 5,30 to 6,28 g per 100 g protein in lysine and 1,72 to 2,04 g per 100 g protein in methionine. In addition, the tested aquatic macrophytes show to be rich in aspartic acid and glutamic acid. However, the effects of lactic acid fermentation on the protein content are conditional and strongly depend on the plant species. According to Cruz et al. (2011), the crude protein in fermented Azolla and Eichhornia decreases (due to slower acidification), but increases in fermented Lemna and Spirodela (maybe through an additional microbial synthesis).

Aquatic macrophytes such as Elodea nuttalli, Vallisneria natans, Alterranthera philoxerides that are widely distributed in water environments have been used as substrate of solid-state fermentation to produce crude protein extraction (Xiao et al., 2009). The experimental results show that the crude protein content of products with mixed strains fermentation is higher than that with single-strain fermentation. The crude protein content in V. natans fermented with the mold strain, Aspergillus niger, and yeast, Candida utilis, (taken in the ratio 1:1at 28^o C for 72 hours) is highest (39,88 %) among the fermented aquatic macrophytes examined in this study.

Among other inoculants to ferment aquatic and terrestrial plants, fish intestinal bacteria are widely used (e.g., Bairagi et al., 2004; Saha & Ray, 2011).

Molasses fermented, cow rumen content fermented and yeast fermented water hyacinth (E. crassipes) have been  incorporated into isonitrogenous and isocaloric test diets for fingerlings of Nile tilapia, O. niloticus, by El-Sayed Abdel-Fattah (2003). In final sum, diets with molasses fermented water hyacinth have been utilized more efficiently than diets with yeast fermented and cow rumen content fermented water hyacinth, respectively. According to Tham et al. (2013), addition of molasses and rice bran as an absorbent, but not an inoculant in the form of fermented vegetable juice (Brassica campestris), improve the quality of fermented water gyacinth as food.

Basic References

Bairagi A.., Sarkar Ghosh K., Sen S.K., Ray A.K. 2004. Evaluation of nutritive value of Leucaena leucocephala leaf meal inoculated with fish intestinal bacteria Bacillus subtilis and Bacillus circulans in formulated diets for rohu, Labeo rohita (Hamilton) fingerlings. Aquaculture Research, 35, 436-446.

Cruz Y., Kijora C., Wedler E., Danier J., Schulz C. 2011. Fermentation properties and nutritional quality of selected aquatic macrophytes as alternative fish feed in rural areas of the Neotropics. Livestock Research for Rural Development 23, article # 239

... Read more »

Fermentation allows to improve significantly nutritional value of wheat, rye, rice, oat and other cereal brans expanding an area of their use in nutrition of human, in particular in baking industry, and animals. In our context, fermented baits and groundbaits are widely used in fishing. Here, we consider briefly some examples and per se practical recipes of wheat, rice and other cereal brans fermentation that will allow you to get the first glimpse of the state of affairs in this important area.

Unhygienic methods of cereal bran fermentation are not considered.

Proximate composition, mineral content and antinutritional factors (tannin, phytic acid) are determined in fermented (with the 0,2 % dry yeast plus 30 ppm ascorbic acid) wheat bran by Hassan et al. (2008). Fermentation of moistured wheat bran in an incubator at 30^o C for 4 hours increases the percentage of crude fiber from 15,67 to 18,67; 15,67 to 18,00; 15,00 to 17,67 for coarse, medium and fine brans. At the same time, protein content is increased from 20,35 to 21,65; 18,36 to 20,79 and 21,07 to 22,40 for wheat bran with the foregoing particle size, respectively. Carbohydrates percentage increases from 45,09 to 47,40 in fermented coarse wheat bran. Both antinutritional factors (tannins and phytic acid) are found to decrease significantly in coarse, medium and fine wheat bran. Functional properties of cereal brans fermented by Aspergillus oryzae and Rhizopus sp. in the solid-state system are determined by Silveira & Badiale-Furlong (2009) with an aim to evaluate their application in food formulation. The defatted rice bran and wheat bran have been inoculated with the spores of the cultures and incubated at 30°C for zero, 24, 48 and 72 hours. Protein content, protein solubility, in-vitro digestibility, gelation and water holding capacity have been determined in bran with or without fermentation. Rhizopus sp. increases significantly the protein content (69,0 % and 56,0 % for the defatted rice bran and wheat bran, respectively), protein solubility (28,5 % and 36,2 %) as well as water holding capacity (11,4 % for wheat bran).

Other aspects of rice bran fermentation are considered in many papers (e.g., Oliveira et al., 2011; Kupski et al., 2012).

Oduguwa et al. (2008) have carried out experiments to evaluate the effect of fermentation on the composition of corn cob, rice bran and cowpea (Vigna sp.) husk to use them in composite rabbit feed formulations. The test ingredients have been moistened with the tap water and allowed to ferment naturally at room temperature during zero, 24 and 48 hours. The microorganisms associated with the fermenting materials are identified as Rhizopus oligosporus, Aspergillus oryzae, Aspergillus niger, Rhodotorula, Geotrichum candidum, Candida albicans and Saccharomyces cerevisiae. According to Odugawa et al. (2008), S. cerevisiae enhance the protein and fat contents in the fermented materials while R. oligosporus are able to degrade the fiber significantly.

Basic References

Hassan E.G., Award Alkareem A.M., Mustafa A.M.I. 2008. Effect of fermentation and particle size of wheat bran on the antinutritional factors and bread quality. Pakistan Journal of Nutrition 7, 521-526

Kupski L., Cipolatti E., da Rocha M., Oliveira M.S., de Souza-Soares L.A., Badiale-Furlong E. 2012. Solid-state fermentation for the enrichment and extraction of proteins and antioxidant compounds in rice bran by Rhizopus oryzae. Brazilian Archives of Boilogy and Technology 55, 937-942

Oduguwa O.O., Edema M.O., Ayeni A.O. 2008. Physico-chemical and microbiological analyses of fermented corn cob, rice bran and cowpea husk for use in composite rabbit feed. Bioresource Technology 99, 1816-1820

Oliveira M.S., Feddern V., Kupski L., Cipolatti E.P., Badiale-Furlong E., de Souza-Soares L.A. 2011. Changes in lipid, fatty acids and phospholipids composition of whole rice bran after solid-state fungal fermentation. Bioresource Technology 102, 8335-8338

Main results described in this book are obtained during fishing trips of author and his friends in the Russian Federation (in its Europen part up to Volga river), Belarus, Ukraine, Moldova, partly in Baltic countries, Poland and Germany, beginning from 1970s. The main part of field experiments have been carried out in Dnipro river, in Ukraine, in three localities: village Pekari (near the Biological Station of the Kyiv National Taras Shevchenko University), Cherkasy region, Kyiv city (the capital of Ukraine), Kyiv region, village Nedanchychi (near the former Sports Base for Hunters & Anglers), Chernigiv region, as well as in Khorol river in one locality: village Khomutets (near the Castle of Ivan Murav’yov-Apostol), Poltava region.

In the book, these localities no longer appear.

Represenatives of the following families of fish have been observed and tested (mainly in the field): Cyprinidae, Gasterosteidae, Percidae, Gobiidae (many of the Black Sea gobiid fish migrate into the rivers of this basin, including Dnipro river), Esocidae (Esox lucius), Centrarhidae (introduced pumpkinseed, Lepomis gibbosus, mainly in Danube delta and lakes), Salmonidae (Salmo trutta), Thymallidae (Thymullus thymulls), Acipenseridae, Anguillidae (Anguilla anguilla), Gadidae (Lota lota), Siluridae (Silurus glanis), Ictaluridae, Cobitidae, Eleotridae (invasive Percottus glehni), Cichlidae, Characinidae and Poecilidae (in laboratory), Labridae and Belonidae (Belone belone) (in the Black Sea) as well as Clupeidae (including the Black Sea sprat, Clupeonella cultriventris, migrated in fresh waters up to Belarus rivers) and Syngnatidae (including black-striped pipefish, Syngnathus nigrolineatus, also migrated in fresh waters up to Belarus rivers).

The most abundant freshwater bentivorous common roach, Rutilus rutilus, and piscivorous common perch, Perca fluviatilis, are used as model fish.

Other invasive fish, first of all in Belarus, northern and middle parts of Ukraine (e.g., Semenchenko et al., 2009; Mastitsky et al., 2010; Slynko et al., 2011), in farms, artificial reservoirs, natural lakes and rivers, have been observed.

Basic References

Mastitsky S.E., Karatayev A.Y., Burlakova L.E., Adamovich B.V. 2010. Non-native fishes of Belarus: diversity, distribution, and risk classification using the Fish Invasiveness Screening Kit (FISK). Aquatic Invasions 5, 103-114

Semenchenko V.P, Rizevsky V.K., Mastitsky S.E., Vezhnovets1V.V., Pluta M.V., Razlutsky V.I., Laenko T. 2009. Checklist of aquatic alien species established in large river basins of Belarus. Aquatic Invasions 4, 337-347

Slynko Y.V., Dgebuadze Y.Y., Novitskiy R.A., Kchristov O.A. 2011. Invasions of alien fishes in the basins of the largest rivers of the Ponto-Caspian Basin: Composition, vectors, invasion routes, and rates. Russian Journal of Biological Invasions 2, 49-59

It is no secret that the most of amateur and professional anglers have not basic knowledge on fish behaviour, an area of fish vital functions that is studied by ethology. On the other hand, the most of ethologists do not know that an area of artificial fishing lures is the most extensive area of scientific, design and applied activity of human, where the numerous artificial stimuli are used.

The book "Fishing: an ethological approach” takes an intermediate position between these  extremes. The following main directions are developed in the book offered to your attention.

Elaborating the newest artificial, seminatural and natural lures, baits, groundbaits and attractants is the first direction. In the framework of this direction, you will know, for example, about the most strong  feeding attractants that can include up to 100 ingredients plus infochemicals, cannot be repeated artificially and knock down any other attractants, or about the most strong fish aggregators that allow to attract thousands of small baitfish and, in turn, tens of predatory fish.

The second direction is connected with the verification of new and available commercial lures, baits, groundbaits and attractants based on field or laboratory statistically grounded experiments. In particular, field testing commercial lures, baits, groundbaits and attractants show that the publicized effectiveness of many of them is falsfied or exaggerated, the use of groundbaits with ingredients alien to the freshwater environment leads to the eutrophication of this environment.

Finally, some general aspects of fish ethology and ecology form the third direction.

The content of the book is represented in the form of relatively short posts that are more readable than long articles. Short posts in e-format are easily edited and modified. This format leads to some repetitions, but these repetitions contribute to the better memorization of the materials.

The first edition of the book contains more than 100 posts. The book is written in language close to the language of the journal "Scientific America”.