Showing papers in "Aquaculture in 1981"

TL;DR: Investigating the effect of extrusion processing and steam pelleting on pellet durability, pellet water absorption and the physiological response of rainbow trout reared upon these diets found extruded pellets to be more durable, had superior water stability and absorbed more water than steam pellets.

TL;DR: In this article, Hermetia illucens larvae were fed to channel catfish and tilapia, alone, and in combination with high-(45%) and low-(30%) protein commercial diets.

TL;DR: Oysters developed from treated zygotes set normally and subsequent survival was indistinguishable from those of controls, and juvenile oysters had about the same percentage of polyploid individuals as embryos.

TL;DR: During smoltification of coho salmon in freshwater (April–May), dramatic increases in both plasma T 4 and gill Na + K + ATPase activities were observed and found to be significantly related, suggesting that they may be freshwater developmental phenomena which prepare the fish for seawater entry rather than serving as regultory mechanisms after seawaterEntry.

TL;DR: Nitrogen-starved plants of the red alga Gracilaria tikvahiae assimilate ammonium-nitrogen very rapidly, doubling their total tissue nitrogen content in 8 h or less, and their growth rate declines.

TL;DR: Of the three environmental factors investigated, temperature had the stongest influence on growth of sockeye, coho, and fall chinook fry, and Hypo-osmoregulatory ability of juvenile coho in sea water was influenced by photoperiod, but none of the photoperperiod treatments produced optimum os moregulatory performance.

TL;DR: It could be calculated that, when the rations are readjusted only once a week, the high growth rates occurring in these experiments result in a considerable difference between the designated feeding rates and the actual feeding rates.

TL;DR: Purified diets with 0, 2, 4, 8, 16 and 32 mg supplemental copper/kg were fed for 16 weeks to channel catfish fingerlings and copper levels in liver were significantly higher in fish fed 32 copper/ kg than those fed the unsupplemented diet.

TL;DR: From the present knowledge it appears that important fish species such as rainbow trout and carp are not inferior with regard to dietary protein utilization to terrestrial farm animals.

TL;DR: Acute septicemia following handling operations was a frequent cause of mortality among Sparus aurata reared in the facilities of the I.O.R.L. Mariculture Laboratory at Elat and at least six distinct strains were isolated, with Vibrio alginolyticus being the most frequently isolated species.

TL;DR: Increased densities were found to yield a high production in a culture system of a relatively small capacity and showed the fish production and weight gain per m 3 water as well as the feed conversion rate to increase with stock density.

TL;DR: Formic acid at all levels tested seems to have a depressive effect on both growth and proteolytic activities, and acidified feeds showed lower feed utilizations than the control feed, this being most pronounced for the formic acid silage.

TL;DR: Apparent digestibilities of individual amino acids from three regions of the gastro-intestinal tract of carp were determined by the chromic oxide method after feeding a protein and an amino acid diet, and the essential amino acids generally showed higher values of absorption than non-essential amino acids, regardless of diet fed.

TL;DR: A comparison of the tissue fatty acid patterns suggests that P. indicus showed a limited capacity to chain elongate and desaturate linoleic and linolenic acids to C20 and C22 successor acids which characterise the wild-type fatty acid composition.

TL;DR: The composition of the stomach contents of the different fry species was analyzed in relation to the composition of some zooplankton and zoobenthos taxocoenoses in the embayment.

TL;DR: The growth response of the fish at nitrite concentration levels with significant mortality was extremely variable and the reduction in growth at the highest nitrites concentration without mortality was only 20%.

TL;DR: Larvae of the giant clams Tridacna gigas, T. derasa, and T. squamosa were reared in the laboratory, and juveniles were cultivated outdoors in a sunlit, flowing seawater system to predict high projected growth/year.

TL;DR: Changing the soy lethicin to 7.5% of the dry weight of the diet significantly decreased mortality in juvenile American lobsters and hybrid H. gammarus, and this mortality syndrome has been termed molt death syndrome.

TL;DR: It has been demonstrated that astaxanthin is stable in an acid silage of shrimp processing waste, but for a slow conversion of its diester to the corresponding monoester.

TL;DR: There was no interaction between diet and family for growth, indicating that the prospects for selectively breeding a strain of rainbow trout specifically better able to utilize carbohydrate are not promising, and the fish fed high levels of carbohydrate had significantly better apparent digestibility of energy and protein.

TL;DR: Juvenile oysters, Crassostrea virginica, were fed one of six diets consisting of three species of algae fed singly or in two-species combinations as mentioned in this paper, and the high growth response with Diet TI was not explained by measured values of ingestion and assimilation.

TL;DR: Different trials were undertaken to substitute a prepared diet for freeze-dried algae Platymonas suecica, as food for Brachionus plicatilis in continuous culture with renewal of a quarter of the volume daily, with good yield and better survival rates than with algae-fed rotifers.

TL;DR: The addition of living mysids to the diets positively influenced the growth increase and food conversion rates in Turbot larvae fed with mass-cultured rotifers and copepods.

TL;DR: Analyses showed that the dry alginate-bound food particles lost an average of 28% protein and 50% lipid during processing and rehydration prior to feeding and total loss of protein and lipid amounted to 39%–47% and 38%–76%, respectively.

TL;DR: There is a highly linear relationship between the percentage of A1 eggs and the hatching rate in spawnings from ablated females of both pond and wild stock.

TL;DR: The clinical, histological and immunofluorescent findings in this case of larval oyster vibriosis in a commercial hatchery demonstrated a pathogenesis which was identical to that previously reported in experimental vibRIosis.

TL;DR: It was found that the latter species is less useful for intensive rearing in ponds jointly with the common carp, and the drop in common carp production with bighead was so considerable that there are doubts as to the usefulness of joint rearing of the two species in ponds.

TL;DR: Phosphorus loss rates from earthen ponds and sediment-water systems in plastic pools were similar to those observed in laboratory systems, but the rates of phosphorus uptake were similar for all systems.

TL;DR: It was concluded that carp larvae and post-larvae with anInitial body weight of 9.5 mg and above exhibit an improved ability to utilise and survive upon an artificial diet, compared with larvae of a lower initial body weight.

TL;DR: In this article, the sperm survival is improved after storage in an O2 atmosphere in comparison with storage in air. But this variability in the response still limits the practical application of short-term preservation of rainbow trout sperm.