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Intensive Culture (intensive + culture)
Selected AbstractsComparison of Three Culture Methods for the Intensive Culture of Northern Quahog Seed, Mercenaria mercenariaJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2001Timothy J. Pfeiffer A number of approaches have been utilized for growing bivalve hatchery seed (1 mm) to a size suitable for field planting (< 8 mm) but few have been directly compared. This study evaluated the growth and survival of northern quahog seed in three different culture systems and two different stocking densities. The three systems were: 1) a stacked-tray unit with downward water flow; 2) traditional upweller culture units with water flowing upward without seed bed expansion; and 3) upweller culture units with water flowing upward at fluidization velocities to provide seed bed expansion. The two stocking densities were 1.0 and 3.0 g whole wet weight clam/cm2 respectively. During each trial period the seed clams were fed a 1% daily ration (% dry weight algae per wet weight clam per day) of the cultured diatom Chaetoceros muelleri. After 14 d of culture at the 1.0 g whole wet weight/cm2 stocking density, seed clams (4.4 ± 0.6 mm initial shell length) under fluidized-flow condition exhibited better growth (0.54/d), and a greater final shell length (5.9 ± 1.0 mm). At the high density stocking conditions, after 28 d of culture, seed clams (4.2 ± 0.6 mm initial shell length) in the fluidized-flow culture conditions again exhibited better growth rate (0.031/d) and a greater final shell length (6.0 ± 1.0 mm). The preliminary evaluation of fluidized-flow for seed clam culture in land-based nurseries indicates its potential as a suitable alternative to raceway, downwelling, or traditional forced-flow culture methods. [source] Sibling cannibalism in dorada under experimental conditions.JOURNAL OF FISH BIOLOGY, Issue 4 2000II. Effect of initial size heterogeneity, light regime on early cannibalism Cannibalism among embryos and larvae of Brycon moorei (Characidae) occurs during daytime and night-time, and persists under permanent darkness. Embryos and larvae of dorada-provisioned with formulated feed over the first week of exogenous feeding did not survive, except for those exerting cannibalism. When offered alternative fish prey [embryos of Prochilodus magdalenae (0·5,0·8 mg) and Oreochromis niloticus (9,10 mg)], 1-day-old embryos of dorada preferred preying on these, thereby reducing early cannibalism. However, this promoted depensatory growth and more intense cannibalism later in the larval stage. Dorada provisioned with Artemia nauplii in excess showed more homogeneous growth and higher survival, most cannibalistic acts being restricted to the first 24 h of exogenous feeding, just after oral teeth were fully developed (21 h after hatching). Provisioning dorada with Artemia nauplii a few hours before their oral teeth were fully developed reduced early cannibalism from 41 to 15%. High proportions of deformed fish caused higher mortality, both directly and indirectly, as they promoted early cannibalism, depensatory growth and more intense cannibalism among larvae. The initial sorting of embryos, based on their occupation of the water column improved survival significantly during the first week of exogenous feeding, up to 52% in progenies containing <10% of deformed fish. Size-grading of larvae and young juveniles over the next 2 weeks reduced cannibalism to 2·6 and 1·9% day,, in the first and second weeks, respectively. These results indicate that cannibalism in dorada can be mitigated efficiently through appropriate rearing procedures, and open promising perspectives for the intensive culture of this fast-growing tropical species. [source] INTEGRATING INTENSIVE AQUACULTURE OF CHONDRACANTHUS EXASPERATUS, THE TURKISH TOWEL SEAWEEDJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Waaland, J. R. Department of Botany, University of Washington, Seattle, WA 98195 USA A new, high value product from the Turkish Towel Seaweed, Chondracanthus exasperatus, was developed recently by a Seattle company. However, Washington State has a long term moratorium on commercial seaweed harvesting from wild populations so there is renewed interest in intensive cultivation of this species. The initial phase of this research was conducted at Mukilteo, Washington. There, strategies for long term cultivation in tanks were tested, and a custom cultivation tank design was developed for pilot scale cultivation research at a site on the shore of Clam Bay near Manchester, Washington. Long term cultivation is now being tested in tanks of up to 5000 L volume supplied with natural seawater, seawater supplemented with nutrients, and seawater effluent from nearby Pacific Halibut culture tanks. Seawater from Clam Bay is naturally rich in nutrients from tidal driven upwelling and nearby commercial salmon mariculture operations. Supplemental nutrients (commercially available "f/2" enrichment) and halibut culture tank effluent have both been tested for their ability to support C. exasperatus growth with relatively low seawater turnover rates. Compared to seawater at the site, Halibut tank effluent differs in both nutrient composition and quantities. Initial results indicate that halibut tank effluent is a satisfactory source of nutrients for C. exasperatus in intensive culture and that the Turkish Towel Seaweed scrubs significant quantities of nutrients from halibut tank effluent. [source] Effects of a peroxide-based commercial product on bacterial load of larval rearing water and on larval survival of two species of Sparidae under intensive culture: preliminary studyAQUACULTURE RESEARCH, Issue 4 2009Gemma Giménez-Papiol Abstract Larvae of two Mediterranean Sparidae species, Sparus aurata and Dentex dentex, were used to test the efficacy of a peroxide-based product (Ox-Aquaculture©) on the reduction in bacterial load in larval rearing water and its effects on larval survival. Eleven-day-old S. aurata larvae and 15-day-old D. dentex larvae were exposed to different concentrations of Ox-Aquaculture© (50, 100 and 200 mg L,1, and 20 and 50 mg L,1 respectively) for 1 h. Results indicated that 50 and 20 mg L,1 were the most effective concentrations for the reduction in bacterial load (at least one order of magnitude) after 1 h treatment, without affecting larval survival and/or vitality in 11 dph S. aurata and 15 dph D. dentex larvae respectively. Ox-Aquaculture© concentrations of 200 and 50 mg L,1 during 1 h affected negatively final survival rate of the larvae of S. aurata and D. dentex respectively. [source] Weaning Chinese perch Siniperca chuatsi (Basilewsky) onto artificial diets based upon its specific sensory modality in feedingAQUACULTURE RESEARCH, Issue 2001X F Liang Abstract Chinese perch are one of the most valuable food fish in China, but the sole source of feed for intensive culture is live prey fish. Our previous studies on systematic sensory physiology revealed that this species have a mechanism for this peculiar feeding habit. In the present study, a specific training procedure was designed, and both experimental (initial body weight 171.0 g; 120 days) and commercial (initial body weight 52.4 g; 240 days) net-cage cultures were conducted to investigate the training success, growth performance and survival of the trained yearlings fed with nonlive or Oregon-type moist diet. The training successes of minced prey fish and the Oregon moist diet were 100 and 89.9%, respectively, in experimental culture, and 92.2 and 83.5% in commercial culture. In an experimental trial, the fish fed minced prey fish or the Oregon moist diet attained final body weights of 472.7 g or 344.7 g, although the specific growth rates of these groups were significantly lower than that of the fish fed live prey fish (final body weight 560.0 g). Mortality was not significantly related to dietary treatment. In commercial culture, the final body weights were as follows: 750 g on live prey fish, 705 g on minced prey fish and 651 g on the Oregon moist diet. Feed costs to produce 1 kg fish were estimated to be US$6.59 for live prey fish, US$1.76 for minced prey fish and US$2.07 for the Oregon moist diet. The results of the present study confirmed that sensory modality and associative learning appear to be critical factors in determining food discrimination of Chinese perch, indicating that both minced trash fish and Oregon-type moist diet can be substituted for live prey fish in intensive commercial production. [source] Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriaeAQUACULTURE RESEARCH, Issue 7 2010Svend J Steenfeldt Abstract Copepods are well known to be the optimal live feed for most species of marine fish larvae. Still copepods are rarely used in marine hatcheries worldwide. Lack of efficient production techniques are among the reasons for this. Consequently, Artemia and rotifers are utilized in commercial settings. One problem in intensive production of copepods is contamination with rotifers. Rotifers have higher growth rates than copepods and consequently will compete out the copepods when accidentally introduced to the copepod production systems. Once contamination has occurred, the only cure has been to shut down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L,1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L,1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis in T. holothuriae batch cultures. [source] | ||||||||||