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ABSTRACT Ten locally available substrates, five biodegradable and five non-degradable, were evaluated for their potential to harbor periphyton in cement tanks fertilized with poultry manure. The tanks were fertilized regularly and the periphyton was allowed to grow for 70 days. Weekly samples of periphyton and plankton were collected for enumeration and biochemical analyses. Among the substrates, earthen tiles harbored negligible amount of periphyton. The phytoperiphyton genera encountered on the substrate belonged mainly to Chlorophyceae (14 genera), followed by Cyanophyceae (2 genera), Chrysophyceae (1 genus), Bacillariophyceae (1 genus), and Dinophyceae (1 genus). Nauplius, Keratella, Diaptomus, Cyclops, Moina, Chironomus and insect eggs were the zooplankton encountered on substrates. Phytoplankton density was higher on tyre (86,426 cells or colonies/cm2) and palm leaf (85,808 cells or colonies/cm2) and lowest on ceramic tile (21,081 cells or colonies/cm2). Glass plates harbored the highest number of zooplankton species per unit area (1050 cells or colonies/cm2), while arecanut leaf-sheath had the lowest (210 cells or colonies/cm2). All five families of phytoplankton present on the substrates were also present in tank water. While periphyton contained 26 genera, tank water had only 24. Periphytic dry matter, ash, ash-free dry matter, plankton density on substrates and water showed a general increase with respect to time. Polyvinyl chloride (PVC) (0.972 mg/cm2), glass (0.913 mg/cm2), and bamboo (0.897 mg/cm2) had higher periphytic dry matter and ceramic tile (0.262 mg/cm2) the lowest. All the proximate composition parameters of periphyton, except nitrogen free extract (NFE) varied significantly (P < 0.05) between the substrates. The moisture content of periphyton ranged from 85.58% (bamboo) to 95.27% (arecanut leaf-sheath). Crude protein was high in periphyton from bamboo (3.77%) and tyre (3.66%) and low in that from arecanut leaf-sheath (0.99%). 相似文献
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Rohu, Labeo rohita (Ham.), fingerlings (average wt 3.38 g) maintained in 25 m2 cement tanks were fed fish-meal-based, 300 g kg−1 protein diets containing different levels (0, 0.25, 0.5, 0.75 and 1.0 g kg−1 ) of L -carnitine in triplicate over a period of 126 days. Fish that received 0.5 g kg−1 carnitine showed significantly higher growth than those fed the basal diet or the rest of the carnitine diets. Fat digestibility, food conversion efficiency and protein efficiency ratio were better in carnitine-fed fish; however, viscerosomatic and hepatosomatic indices decreased. Muscle proximate composition was affected as a result of carnitine treatment. The results of the present study demonstrate a positive effect of carnitine on the growth and body composition of rohu. 相似文献
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P. Keshavanath J. K. Manissery A. Ganapathi Bhat B. Gangadhara 《Journal Of Applied Aquaculture》2013,25(1):60-68
Four locally available biodegradable substrates—sugarcane (Saccharum officinales) bagasse, palm (Borasus flabellifera) leaf, coconut (Cocos nucifera) leaf, and bamboo (Bambusa bambos) mat—were evaluated for the production of periphyton and a polyculture of rohu (Labeo rohita) and common carp (Cyprinus carpio) in poultry-manured ponds. Chlorophyll-a, phaeophytin-a, and total pigment content of periphyton were not significantly different (P > 0.05) among substrate types. Dry matter and ash-free dry matter of coconut leaf periphyton were significantly higher (P < 0.05) than that of the other substrates. All four substrates induced significantly (P < 0.05) higher growth, production, and survival of rohu and common carp. Among the substrates used, coconut leaf was more effective in enhancing fish production. 相似文献
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The effect of feeding Spirulina platensis on the growth, carcass composition, organoleptic quality, digestive enzyme activity and digestibility of common carp, Cyprinus carpio L., was studied through a culture trial lasting 120 days. Four experimental diets were employed by replacing fish meal protein from the standard diet at 25%, 50%, 75% and 100% through the incorporation of Spirulina. Another diet with Spirulina as the sole source of protein was also used. The final weight gain, specific growth rate, food conversion ratio and protein efficiency ratio of common carp were not affected by Spirulina supplementation. However, the diet with Spirulina as the sole source of protein resulted in better net protein retention. The muscle RNA:DNA ratio of fish fed Spirulina diets was higher than that of fish fed control diet. There was no significant difference in carcass moisture and protein content in the fish fed Spirulina diets as compared to fish-meal-based control diet. The carcass ash and fat contents were positively and negatively correlated with dietary Spirulina level, respectively. Organoleptic evaluation revealed no effect of Spirulina feeding on the quality of both raw and cooked fish. The gut digestive enzyme activity did not show any definite trend with respect to Spirulina supplementation. Spirulina improved the protein digestibility of the diets. 相似文献
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Abstract
Fanners employing crude human chorionic gonadotropin (Sumach, Infar India Ltd.) for inducing breeding of major carps, in India have claimed that it also promotes growth. The present study was undertaken in order to confirm this and its potential statics pure HCG (Sigma Chemicals Ltd), wherein two experiments were conducted in a recirculatory system. In the first experiment of 84 days duration, 10 mg/kg diet Sumach induced significantly higher growth, but not 20mg/kg diet. Both doses of pure HCG tried (1 and 2 mg/kg diet) were ineffective. In the second experiment, growth produced by 5 mg/kg diet pure HCG and 10 mg/kg diet Sumach were comparable and significantly higher than the rest after 42 days, indicating higher potential of pure HCG. The findings are significant as they reveal that a protein hormone like HCG is capable of growth promotion in carp when administered orally 相似文献
Fanners employing crude human chorionic gonadotropin (Sumach, Infar India Ltd.) for inducing breeding of major carps, in India have claimed that it also promotes growth. The present study was undertaken in order to confirm this and its potential statics pure HCG (Sigma Chemicals Ltd), wherein two experiments were conducted in a recirculatory system. In the first experiment of 84 days duration, 10 mg/kg diet Sumach induced significantly higher growth, but not 20mg/kg diet. Both doses of pure HCG tried (1 and 2 mg/kg diet) were ineffective. In the second experiment, growth produced by 5 mg/kg diet pure HCG and 10 mg/kg diet Sumach were comparable and significantly higher than the rest after 42 days, indicating higher potential of pure HCG. The findings are significant as they reveal that a protein hormone like HCG is capable of growth promotion in carp when administered orally 相似文献
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Ramanath M Mridula Joseph K Manissery Perar Keshavanath Kalkuli M Shankar Mudnakudu C Nandeesha & Kothanahally M Rajesh 《Aquaculture Research》2005,36(7):635-642
Sugarcane bagasse (T1), paddy straw (T2) and their mixture (T3) were added to mud‐bottomed, manured cement tanks in triplicate to study the effect on bacterial biofilm production and growth and survival of rohu, Labeo rohita. All tanks were stocked with fingerling rohu at 10 000 ha?1. The total plate count (TPC) of bacteria in water and on substrate did not differ significantly between treatments. The mean phytoplankton and zooplankton density in water was the highest in T2, followed by T3 and T1. The growth of fish was significantly (P<0.05) higher in T2 and T3 compared with T1. Significantly higher RNA values were recorded in T2 and T3 compared with T1. Similarly, T2 and T3 registered higher DNA values than T1. RNA:DNA ratio was higher in T2 compared with T1. However, T3 did not differ significantly from T1 and T2. Both intestinal and hepatopancreatic protease and lipase activity was higher in T1 and T2 compared with T3 and both differ significantly from T1. Intestinal amylase activity was higher in T2 and T3 compared with T1, whereas hepatopancreatic amylase activity was higher in T2 compared with T1 and T3. The results demonstrated that production of L. rohita can be significantly increased by the introduction of biodegradable substrates into culture systems where fertilization is employed. 相似文献
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Use of artificial substrates to enhance production of freshwater herbivorous fish in pond culture 总被引：1，自引：0，他引：1
P Keshavanath B Gangadhar T J Ramesh J M van Rooij M C M Beveridge D J Baird M C J Verdegem & A A van Dam 《Aquaculture Research》2001,32(3):189-197
Two trials were conducted in mud‐bottomed concrete tanks to assess the potential of using artificial substrates to enhance fish production in ponds. Three substrate types were tested: bamboo poles, PVC pipes and sugarcane bagasse bundles. In one trial, periphyton was grown on the substrates in the absence of fish. In the second trial, masheer (Tor khudree Sykes) fingerlings were stocked at three densities. Results showed a significant effect of substrate type on fish growth (P≤ 0.001) and on net fish production (P≤ 0.05), with best growth in the tanks using the bamboo substrate. In the bagasse treatment, 100% fish mortality occurred. Highest extrapolated periphyton‐based gross fish yield (i.e. without feed inputs) was 450 kg ha?1 90 d?1 with PVC and 491 kg ha?1 90 d?1 with bamboo substrate. The best periphyton growth occurred on bamboo, followed by bagasse and PVC. Without fish, mean periphyton biomass during the culture period was 0.56–1.20 mg cm?2 on bamboo [ash‐free dry matter (DM)], against 0.09–0.36 mg cm?2 on PVC and 0.20–0.59 mg cm–2 on bagasse. No clear effect of fish density or water depth on periphyton biomass could be seen. Only on bamboo, fish density seemed to have a negative effect on periphyton ash‐free dry matter and a positive effect on pigment content (chlorophyll‐a and phaeophytin). Periphyton from bamboo had a lower ash content (38–47% of DM) than from PVC (54–55% of DM) or bagasse (51–58% of DM). It is concluded that substrate type has a strong effect on periphyton productivity and composition, and on fish productivity. Good fish production was achieved without feed inputs. More research is needed to study the economic viability of periphyton‐based systems in the context of Indian aquaculture. 相似文献
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