Difference between revisions of "Algae for Tilapia"
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| − | Tilapia (Oreochromis niloticus) may effectively control algal blooms in eutrophic waters.[http://link.springer.com/article/10.1007/s10750-006-0023-5#page-1 | + | Tilapia (Oreochromis niloticus) may effectively control algal blooms in eutrophic waters.[http://link.springer.com/article/10.1007/s10750-006-0023-5#page-1] Blue-green algae are common components of the Tilapia diet. In the stomach of Tilapia nilotica the cells of blue-green algae are lysed by high concentrations of acid (pH 1.4–1.9). After lysis, cell contents are digested in the intestine (by pepsinogen, a pancreatic α-amylase, trypsin, chymotrypsin and esterase activity). Acid is secreted in relation to feeding. Acid is not secreted by stressed fish.[http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1973.tb07514.x/abstract] |
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| − | + | Tilapia feed selectively on large algae, mainly cyanobacteria and diatoms.[http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2427.2005.01407.x/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false] Nile tilapia is particularly effective in filtering the larger particle size taxa.[http://www.sciencedirect.com/science/article/pii/S0044848602001333] | |
| + | Ingestion rates are higher on Anabaena cylindrica (larger filamentous cyanobacteria that exists as plankton) than on Microcystis aeruginosa (freshwater cyanobacteria that produce neurotoxins and hepatotoxins).[http://link.springer.com/article/10.1007/BF00002160#page-1] Surface-grazing on periphyton (mixture of algae, cyanobacteria, heterotrophic microbes and detritus attached to submerged surfaces) is also greater than on Microcystis aeruginosa. For tilapia, filter-feeding may be a relatively unimportant method of ingesting algae.[http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.1993.tb00573.x/abstract] | ||
| − | + | ==Algae meal== | |
| − | + | Under most unnatural feeding conditions tilapia are unable to sufficiently ingest high volumes of algae. They may need constant grazing to fulfill their nutrient requirements.[http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.1995.tb01868.x/abstract] Tilapia (Sarotherodon niloticus) grow better on fishmeal than on a 25% protein green algae meal (Cladophora glomerata). Weight gain decreased as the level of algal protein increased as replacement of fish meal. Protein digestibility was highest on a 5:1 ratio (fishmeal : green algae meal).[http://www.sciencedirect.com/science/article/pii/0044848683901485] Protein synthesis (with normal sulfur and carbon content) by green algae during the night may match protein synthesis during the day (in Dunaliella tertiolecta).[http://m.aslo.info/lo/toc/vol_29/issue_4/0731.pdf] Protein derived from algae does not promote adequate growth in Rainbow trout.[http://www.sciencedirect.com/science/article/pii/0044848678900972] Green algae ulva meal may replace soy bean meal to the extend of 20% without negatively affecting growth of male larval tilapia. Feed conversion ratio increased with increasing ulva meal content.[http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0426.2007.01017.x/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false] | |
Revision as of 17:38, 30 September 2014
Tilapia (Oreochromis niloticus) may effectively control algal blooms in eutrophic waters.[1] Blue-green algae are common components of the Tilapia diet. In the stomach of Tilapia nilotica the cells of blue-green algae are lysed by high concentrations of acid (pH 1.4–1.9). After lysis, cell contents are digested in the intestine (by pepsinogen, a pancreatic α-amylase, trypsin, chymotrypsin and esterase activity). Acid is secreted in relation to feeding. Acid is not secreted by stressed fish.[2]
Tilapia feed selectively on large algae, mainly cyanobacteria and diatoms.[3] Nile tilapia is particularly effective in filtering the larger particle size taxa.[4] Ingestion rates are higher on Anabaena cylindrica (larger filamentous cyanobacteria that exists as plankton) than on Microcystis aeruginosa (freshwater cyanobacteria that produce neurotoxins and hepatotoxins).[5] Surface-grazing on periphyton (mixture of algae, cyanobacteria, heterotrophic microbes and detritus attached to submerged surfaces) is also greater than on Microcystis aeruginosa. For tilapia, filter-feeding may be a relatively unimportant method of ingesting algae.[6]
Algae meal
Under most unnatural feeding conditions tilapia are unable to sufficiently ingest high volumes of algae. They may need constant grazing to fulfill their nutrient requirements.[7] Tilapia (Sarotherodon niloticus) grow better on fishmeal than on a 25% protein green algae meal (Cladophora glomerata). Weight gain decreased as the level of algal protein increased as replacement of fish meal. Protein digestibility was highest on a 5:1 ratio (fishmeal : green algae meal).[8] Protein synthesis (with normal sulfur and carbon content) by green algae during the night may match protein synthesis during the day (in Dunaliella tertiolecta).[9] Protein derived from algae does not promote adequate growth in Rainbow trout.[10] Green algae ulva meal may replace soy bean meal to the extend of 20% without negatively affecting growth of male larval tilapia. Feed conversion ratio increased with increasing ulva meal content.[11]
