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Culture Cycle (culture + cycle)
Selected AbstractsCultivation of the Dible Mushroom Lentinula edodes (Shiitake) in Pasteurized Wheat Straw , Alternative Use of Georthermal Energy in MexicoENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2004G. Mata Abstract Five edible Lentinula edodes strains were evaluated. The mushrooms were cultivated on a wheat straw substrate that was previously pasteurized by immersion in water heated by residual geothermal vapor, which was also used to warm incubation and production rooms. Finely chopped wheat straw (Triticum aestivum L.) was pasteurized and then spawned with supplemented spawn capable of supplying nutrients and enriching the substrate, with the expectation of yield improvement. The samples were incubated for 60,days before the production started and thus, the mushrooms produced had pileus diameters ranging from 5 to 20,cm. The yields fluctuated from 6.2 to 13.9,% (fresh weight of mushrooms/fresh weight of substrate). Biological efficiency ranged from 24.8 to 55.6,% (fresh weight of mushrooms/dry weight of substrate), while the production rate reached varied from 0.19 to 0.55,% (biological efficiency/production time starting from inoculation). The cultivation system evaluated here offers the possibility of lowering production costs by cultivating the mushroom on easily obtainable substrate and shortening the culture cycle. The efficiency of this use of geothermal energy and supplemented spawn for shiitake mushroom cultivation on non-sterilized substrates was proven. [source] Culture-based fisheries in non-perennial reservoirs in Sri Lanka: production and relative performance of stocked speciesFISHERIES MANAGEMENT & ECOLOGY, Issue 4 2005W. M. H. K. WIJENAYAKE Abstract, In Sri Lanka, there is a great potential for the development of culture-based fisheries because of the availability of around 12 000 non-perennial reservoirs in the dry zone (<187 cm annual rainfall) of the island. These reservoirs fill during the north-east monsoonal period in October to December and almost completely dry up during August to October. As these non-perennial reservoirs are highly productive, hatchery-reared fish fingerlings can be stocked to develop culture-based fisheries during the water retention period of 7,9 months. The present study was conducted in 32 non-perennial reservoirs in five administrative districts in Sri Lanka. These reservoirs were stocked with fingerlings of Indian (catla Catla catla Hamilton and rohu Labeo rohita Hamilton) and Chinese (bighead carp Aristichthys nobilis Richardson) major carps, common carp Cyprinus carpio L., genetically improved farmed tilapia (GIFT) strain of Nile tilapia, Oreochromis niloticus (L.) and post-larvae of giant freshwater prawn, Macrobrachium rosenbergii De Man, at three different species combinations and overall stocking densities (SD) ranging from 218 to 3902 fingerlings ha,1, during the 2002,2003 culture cycle. Of the 32 reservoirs stocked, reliable data on harvest were obtained from 25 reservoirs. Fish yield ranged from 53 to 1801 kg ha,1 and the yields of non-perennial reservoirs in southern region were significantly (P < 0.05) higher than those in the northern region. Naturally-recruited snakehead species contributed the catches in northern reservoirs. Fish yield was curvilinearly related to reservoir area (P < 0.05), and a negative second order relationship was evident between SD and yield (P < 0.05). Chlorophyll- a and fish yield exhibited a positive second order relationship (P < 0.01). Bighead carp yield impacted positively on the total yield (P < 0.05), whereas snakehead yield impact was negative. Bighead carp, common carp and rohu appear suitable for poly-culture in non-perennial reservoirs. GIFT strain O. niloticus had the lowest specific growth rate among stocked species and freshwater prawn had a low return. [source] Effects of temperature and salinity on the survival and development of mud crab, Scylla serrata (Forsskål), larvaeAQUACULTURE RESEARCH, Issue 14 2007Rahmi Nurdiani Abstract The combined effects of temperature and salinity on larval survival and development of the mud crab, Scylla serrata, were investigated in the laboratory. Newly hatched larvae were reared under 20 °C temperature and salinity combinations (i.e. combinations of four temperatures 25, 28, 31, 34 °C with five salinities 15, 20, 25, 30, 35 g L,1). The results showed that temperature and salinity as well as the interaction of the two parameters significantly affected the survival of zoeal larvae. Salinity at 15 g L,1 resulted in no larval survival to the first crab stage, suggesting that the lower salinity tolerance limit for mud crab larvae lies somewhere between salinity 15 and 20 g L,1. However, within the salinity range of 20,35 g L,1, no significant effects on survival of zoeal larvae were detected (P>0.05). The combined effects of temperature and salinity on larval survival were also evident as at low salinities, both high and low temperature led to mass mortality of newly hatched larvae (e.g. 34 °C/15 g L,1, 34 °C/20 g L,1 and 25 °C/15 g L,1 combinations). In contrast, the low temperature and high salinity combination of 25 °C/35 g L,1 resulted in one of the highest survival to the megalopal stage. It was also shown that at optimal 28 °C, larvae could withstand broader salinity conditions. Temperature, salinity and their interaction also significantly affected larval development. At 34 °C, the mean larval development time to megalopa under different salinity conditions ranged from 13.5 to 18.5 days. It increased to between 20.6 and 22.6 days at 25 °C. The effects of salinity on larval development were demonstrated by the fact that for all the temperatures tested, the fastest mean development to megalopa was always recorded at the salinity of 25 g L,1. However, a different trend of salinity effects was shown for megalopae as their duration consistently increased with an increase in salinity from 20 to 35 g L,1. In summary, S. serrata larvae tolerate a broad range of salinity and temperature conditions. Rearing temperature 25,30 °C and salinity 20,35 g L,1 generally result in reasonable survival. However, from an aquaculture point of view, a higher temperature range of 28,30 °C and a salinity range of 20,30 g L,1 are recommended as it shortens the culture cycle. [source] Performance evaluation of concurrent rice,fish,prawn culture with and without cull harvestingAQUACULTURE RESEARCH, Issue 9 2010Rajeeb K Mohanty Abstract This study was carried out in farmers' fields for three experimental culture cycles to evaluate the performance of rice,fish,prawn culture. The treatments carried out were deepwater rice mono-cropping (R), and rice,fish,prawn culture with cull harvesting (R,FC) and without cull harvesting (R,F). Water pH and total alkalinity were significantly higher (P<0.05) in R,FC than in R,F, while the concentrations of total suspended solids, plankton and chlorophyll a were higher in R,F. Cull harvesting in R,FC had no marked influence on the concentrations of dissolved oxygen, NH4+, nitrite, nitrate and phosphate compared with the R,F treatment. The significantly higher fish and prawn yields (P<0.05) and species-wise faster individual growth performance in R,FC than in R,F were probably due to periodic cull harvesting, which minimized the competition for food and space as well as physiological stress at reduced density. The paddy yield and percentage increase in paddy yield over rice mono-crop was significantly higher (P<0.05) in R,FC (25%), followed by R,F (16.9%), probably due to lower chlorophyll a (36.7 mg m,3) and plankton density (1.4 × 104 L,1), which minimized the competition for nutrients with rice plants. The highest rice equivalent yield (38.5), output value,cultivation cost ratio (1.56) and enhanced net return (28%) in deepwater rice,fish culture were recorded when cull harvesting was practiced. [source] Feasibility of pacific white shrimp Litopenaeus vannamei culture in southern Brazil: effects of stocking density and a single or a double CROP management strategy in earthen pondsAQUACULTURE RESEARCH, Issue 2 2010Dariano Krummenauer Abstract Marine shrimp culture at southern Brazil is restricted to the warmer season (November to April). Therefore, farmers must consider culture strategies and competition with shrimp landings from artisanal fishery. The fishing season starts every 1 February; in order to obtain higher prices, farmers may consider shrimp culture in two crops, with a first harvest before the start of the fishing season, and a second harvest after the end of the landings. The present study evaluated the performance and feasibility of Litopenaeus vannamei reared at 10, 25 and 40 shrimp m,2 either in two short consecutive culture cycles or one longer cycle (LC). The experimental design consisted of two sets of nine pens installed in a 3.8 ha earthen pond. In one set of pens, shrimp were harvested after 75 days and pens were restocked for another 75-day-long rearing period. In the second set of pens, shrimp were cultured for 150 days. Shrimp survival and final weight ranged from 79% to 91% and 6.67 to 14.53 g respectively. Feasibility analysis pointed towards culture at higher densities (25 and 40 shrimp m,2) in a LC as productivity (2274,4227 kg ha,1) and shrimp final weight (13.05,13.21 g) resulted in higher profitability (US$7761,12 379). [source] | ||||||||||