Showing papers in "Aquaculture in 1982"

TL;DR: The minimum dietary protein level producing maximum growth of S. mossambicus was found to be 40%, with a dietary protein to energy ratio (P : E) of 116.6 mg protein per kilocalorie of calculated metabolizable energy.

TL;DR: All the protein sources except leucaena promoted reasonable growth even at high dietary inclusion levels, and the value of the different plant protein sources is discussed in relation to dietary essential amino acid levels and determined toxic factors.

TL;DR: An improved apparatus for the quantitative automatic collection of fish feces is presented, which may be used for digestibility determinations on natural or artificial foodstuffs with species where feces collection by abdominal pressure for Digestibility measurements is not possible.

TL;DR: It was concluded that regular soybean meal contains 10–15% less available energy and 10-15% more available lysine for carp than the generally accepted values.

TL;DR: Hatcher-reard, precociously mature, yearling male parr survived and grew as well as immature individuals under two temperature-photoperiod regimes and Trends in lipid-moisture dynamics and condition factor of mature and immature individuals followed typical sea-sonal patterns during smolting.

TL;DR: Stress may decrease the performance capacity of a smolt more than that of a parr, and hence have a more profound impact on the ability of migrants to cope with other environmental challenges.

TL;DR: The three pathogens proved to be closely similar to each other but distinct from any Vibrio species, although resembling V. anguillarum biovar I and particularly V. splendidus bore greatest similarity to three strains from Milford, CT, U.S.A., reported in 1965 as pathogens of bivalve larvae.

TL;DR: It is concluded that rapeseed products of the canola type are good protein supplements for chinook salmon and can comprise 13 to 16% of dietary protein (16 to 20%" of dietary dry matter).

TL;DR: The results demonstrated that the tilapia could utilise free amino acids for growth, and the minimum dietary level of methionine at the cystine level employed producing satisfactory growth was less than 0.53%, lower than has been reported for most other fish.

TL;DR: Spontaneous and induced triploid rainbow trout were identified by analysis of the DNA content of red blood cells with flow cytometry and there was no evidence of diploid cells in the triploids individuals.

TL;DR: It is concluded that smolting consists of a number of dynamic, seasonal, reversible and annually recurring processes, which differ substantially from 1 year.

TL;DR: Analysis of changes in plasma thyroid hormones provides useful information regarding the optimal time to transfer coho salmon from fresh water to seawater, and Peaks of thyroid hormones were also observed in chinook salmon and steelhead trout in fresh water.

TL;DR: It is suggested that bimodality of growth in juvenile Atlantic salmon is related primarily to sexual maturity, and only secondarily to smolting.

TL;DR: A study was made of externally measurable features that change significantly during the parr-smolt transformation and appear to reflect chronological age more faithfully than does integumentary pigmentation.

TL;DR: Reviewing the studies undertaken to determine the relationship between hypoosmoregulatory performance in the 24-h seawater challenge test and marine survival of hatchery-reared coho salmon and steelhead trout juveniles reveals temporal and size-related differences in the pattern of development.

TL;DR: The condition of seawater-adapted coho salmon parr may be described as hypofunctional in both development and osmoregulatory ability.

TL;DR: Environmental cues: photoperiod, temperature, and the lunar cycle among others, acting through several endocrine systems including the thyroid, set the timing of smoltification and the careful timing of the thyroxine surge suggests that a highly organized sequential pattern of hormone release and interaction leads directly to the orderly progression ofsmoltification-related developmental events.

TL;DR: Bacterial numbers in dried cysts were relatively low, but there was no evidence of intimate colonization of the nauplii by bacteria, and the loosely attached surface flora was removed readily by washing in sterile sea water.

TL;DR: Despite the lack of any seasonal gill enzymatic activation in the strains of nonmigratory species tested, transfers to seawater could be achieved during certain periods with domestic rainbow and brown trout of large size, whereas brook trout yearlings were unable to control the osmotic stress which resulted in 100% mortality.

TL;DR: The dietary copper: zinc ratio caused some small changes in the plasma and hepatic levels of a few minerals, but no evidence was found to suggest any zinc—copper antagonism in rainbow trout.

TL;DR: Clarification of the relation between peak interrenal activity and peak thyroid activity would define the nature of any association between seawater tolerance and seawater preference, and add clues about the mechanisms initiating changes in the pineal—hypothalamo-hypophysial axis and regulating the timing of smoltification.

TL;DR: In many respects, the abnormal stunt appeared hypoendocrine; however, the growth hormone cells and the corpuscles of Stannius showed ultrastructural signs of appreciable activity.

TL;DR: Harpacticoid copepods were made more available to fish larvae by transfering them to mesh-bottomed floating trays by carrying out preliminary experiments to find out whether these trays could also serve as a culturing site.

TL;DR: Hatching success was affected by the use of eggs derived from either normal or induced ovulation and also by the interval between egg-activation and cold shocking, which resulted in diploid gynogenetic all female coho when eggs were inseminated with irradiated sperm.

TL;DR: The nutritional qualities and freshness of pellets were significantly improved when the time lag between food distribution and start of night time activities of the shrimp was shortened and the nutritional quality and value of pellets was significantly improved.

TL;DR: Loci which were weakly polymorphic in natural populations were observed to be monomorphic in hatchery oysters and loci at which three or more alleles were segregating in wild populations were as genetically variable in the hatchery stock.

TL;DR: The relationship between loadings per unit fish biomass and fish size is illustrated based on data from 16 rearing situations at five farms and the effects of cleaning of the rearing units are illustrated.

TL;DR: The external appearance, swim bladder shape, and anal fin ray number of hybrids were more nearly that of their male parents than their female parents, and susceptibility to capture by seine was influenced more by the male parent than the female parent.