Showing papers in "Aquaculture in 1994"

TL;DR: Recent studies have shown that insulin levels in fish are similar to or often higher than those observed in mammals, thus indicating that fish are not diabetic as previously thought.

TL;DR: Examination of measurements presented in a number of published papers indicates that comparison of proximate compositions on a dry weight basis and failure to include fish size as a covariate have led to erroneous conclusions concerning the effects of environmental and dietary factors on the proximate composition of cultured fishes.

TL;DR: The results suggest that antibiotic-resistant V. harveyi had been colonising larval tanks and showed much lower LD 50 values than isolates from natural seawater, thus indicating their higher virulence.

TL;DR: A wholesome prepared food for the larvae is still unknown to science, but advances in biology and technology seek to break one of the last hurdles in the aquaculture cycle.

TL;DR: Energy needs of fasting salmonids are about 30–80 kJ/kg body weight/day, depending mainly on water temperature, while energy requirements for body growth and tissue deposition have been studied to some extent and current estimates vary between 15 and 18 MJ of DE/kg of live weight gain.

TL;DR: A significant interaction between population and salinity level (two-way ANOVA, P=0.035) indicated that the IHHN-positive population had relatively lower growth at the high salinities level.

TL;DR: Use of high-energy/low-protein diets seems to offer the fish-farming industry a means of reducing protein consumption.

TL;DR: It is suggested that the EFA growth-promoting activity of arachidonic acid provides strong support for the contention that dietary 20:4n−6 is essential for juvenile turbot.

TL;DR: A correlation between the appearance of lordosis in 0.7–4 g juvenile Dicentrarchus labrax and Sparus auratus and the lack of functional swimbladders was found in larval forms of both species and a mechanical cause of this deformity was suggested.

TL;DR: There is preliminary evidence that periods of chronic confinement stress experienced during the final stages of reproductive development not only disrupt the reproductive endocrinology of trout, but also result in reduced egg size in rainbow trout and significantly lower survival rates for progeny from both stressed brown and rainbow trout compared to progenyFrom unstressed controls.

TL;DR: The evidence for an increase as well as a decrease in aggression during domestication in fish is critically evaluated, the various mechanisms by which competitive behavior in fish can affect individual growth rates under natural or artificial conditions are described, and the direction and intensity of any phenotypic change in food-related agonistic behavior following natural orificial selection for rapid growth will depend on the relationship between agonism and access to food.

TL;DR: Recent high-nutrient-dense diet formulations output less than 200 kg solid waste and less than 5 kg P per tonne fish produced, but achieving this reduction of waste output requires completely revised feeding standards based on an average 15 MJ DE/kg salmonid fish produced.

TL;DR: High dietary levels of digestible carbohydrate induced lipogenesis and enhanced lipid deposition in the liver in rainbow trout under the conditions of this study.

TL;DR: Adding bacteria (strain CA2) as a food supplement to xenic larval cultures of the oyster Crassostrea gigas consistently enhanced growth of larvae during different seasons of the year.

TL;DR: There are large variations in the measured essential amino acid requirements of different species of fish when expressed as a proportion of the diet, and the question of whether or not these are real differences is considered.

TL;DR: Fish fed the 44% CP herring meal diet had the highest energy, protein and lipid retention and total ammonia excretion increased linearly and significantly with the protein level of the diet.

TL;DR: The results suggest that a dietary fatty acid composition more closely resembling the freshwater invertebrates might be beneficial for growth, development and the prevention of pathologies in salmon parr.

TL;DR: Because fouling decreases with depth and also varies markedly between localities, judicious choosing of culture sites in term of fouling development could substantially improve meat production.

TL;DR: There were no significant differences in activity of the selenium-containing enzyme, glutathione peroxidase, between the dietary groups, indicating a sufficient selenum status in all groups.

TL;DR: The results suggest that each of these n−3 HUFAs may play different and specific roles in crustacean reproduction and that either or both must be included in the broodstock diet.

TL;DR: Results showed that poultry by-product meal is suitable as a partial or complete replacement, but that complete substitution required amino acid supplementation, principally with lysine and methionine.

TL;DR: The source of lipid had very pronounced effects on the fatty acid (FA) profile of muscle and liver lipids but the variations mainly concerned saturated (in liver only), monounsaturated and 18:2n−6 FAs (in both tissues) and n−3 polyunsaturated FAs were significantly but only slightly modified by the sources of lipid, corresponding for both tissues to that found in other salmonids.

TL;DR: Data compiled from several spawning experiments showed that the interval between hormone administration and initial egg release (latency) was negatively correlated with water temperature over the range of 20-26°C and in each treatment it was nonetheless constant between 22.5 ’ C and 25 ” C.

TL;DR: Growth rate in fresh water was enhanced by elevated water temperature and continuous light, and the LLe group had the lowest growth rate in seawater, suggesting that the continued exposure to LL and elevated temperature interfered with the normal course of parr-smolt transformation.

TL;DR: It is concluded that stocking density affects growth rate of halibut only above a certain threshold level corresponding to 100% coverage of the tank bottom, and the optimal stocking density is somewhere between one and two layers of fish on the tankBottom.

TL;DR: Three types of microparticulate diets for marine larval fish were tested to improve retention of added amino acids after immersion in water, and encapsulating crystalline amino acids within lipid-walled capsules showed promising potential for use in nutritional studies with marine fish larvae.

TL;DR: Energy flow studies for dietary protein, fat and carbohydrate, together with an evaluation of the digestive utilization of these energy-yielding nutrients and their efficiency for feed conversion and growth showed that dietary energy efficiency was directly related to the digestible energy of the diets which was especially influenced by the dietary carbohydrate source.

TL;DR: It is demonstrated that subjecting postlarvae to reduced salinities for 2h provides a simple and rapid test for assaying the physiological condition of postlarval shrimp and suggests that an excessive supply of n-3 may not be beneficial to the shrimp.

TL;DR: Arbitrary primers and the DNA polymerase chain reaction (PCR) technique were applied to study genetic variation between different strains of the crayfish plague fungus, Aphanomyces astaci, and it seems likely that the introduced American signal cray fish has served as a vector and transmitted the pathogen to the indigenous cray Fish.

TL;DR: It is demonstrated that SBM, COM and SM could replace 25, 25, and 50%, respectively, of FM protein in practical diets of silver seabream without any adverse effects on fish growth.