The Annual Growth-Rate Cycle in Brown Trout (Salmo Trutta Linn.) and Its Cause

1961 ◽  
Vol 38 (3) ◽  
pp. 595-604
Author(s):  
D. R. SWIFT
Keyword(s):  
Growth Rate ◽  
Brown Trout ◽  
Salmo Trutta ◽  
High Growth ◽  
Maximum Growth ◽  
Field Work ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Annual Growth ◽  
Annual Growth Rate

1. A regular annual growth-rate cycle is demonstrated in wild and hatchery yearling brown trout; the fish have a high growth rate in the spring and autumn and a low growth rate during the summer and winter of each year. 2. Experimental work with constant-environment aquaria, together with the results of the field work, indicate that the water temperature is the main external environmental factor influencing the growth rate. Maximum growth rate is achieved at 12° C. 3. The reason for the fall in growth rate above 12° C. is discussed and it is suggested that inadequacy of the respiratory system of the fish is the prime cause.

Development of a High Rate 4H-SiC Epitaxial Growth Technique Achieving Large-Area Uniformity

2008 ◽  
Vol 600-603 ◽  
pp. 111-114 ◽  
Author(s):  
Masahiko Ito ◽  
L. Storasta ◽  
Hidekazu Tsuchida
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Free Exciton ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
High Rate ◽  
Intrinsic Defect ◽  
Large Area

A vertical hot-wall type epi-reactor that makes it possible to simultaneously achieve both a high rate of epitaxial growth and large-area uniformity at the same time has been developed. A maximum growth rate of 250 µm/h is achieved at 1650 °C. Thickness uniformity of 1.1 % and doping uniformity of 6.7 % for a 65 mm radius area are achieved while maintaining a high growth rate of 79 µm/h. We also succeeded in growing a 280 µm-thick epilayer with excellent surface morphology and long carrier lifetime of ~1 µs on average. The LTPL spectrum shows free exciton peaks as dominant, and few impurity-related or intrinsic defect related peaks are observed. The DLTS measurement for an epilayer grown at 80 µm/h shows low trap concentrations of 1.2×1012 cm-3 for Z1/2 center and 6.3×1011 cm-3 for EH6/7 center, respectively.

Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories

1975 ◽  
Vol 32 (3) ◽  
pp. 427-448 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Growth Rate ◽  
Population Size ◽  
Total Mortality ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Stock Size ◽  
Slow Growth Rate ◽  
Wide Range

Available data on mortality, growth, reproduction, and stock size in exploited and unexploited populations of lake whitefish (Coregonus clupeaformis) are reviewed with a view to understanding the dynamics of exploited populations and improving their management. Natural mortality ranged from about 0.20 to 0.80 in unexploited populations. In exploited populations total mortality was as high as 0.94. Unexploited populations showed a wide range of growth rates. Growth rate increased with increasing exploitation, and growth rate in all heavily exploited populations was similar to the most rapid growth rate shown by unexploited stocks. Heavily exploited whitefish matured at a younger age and possibly also at a smaller size than those which were unexploited. Limited data on stock size suggest that although total population size declines under heavy exploitation, the vulnerable population remains of similar size.It is concluded that whitefish respond to fluctuations in population size through compensatory changes in growth rate, the difference between growth rate in a population and maximum growth rate is a measure of its scope for compensating for increased mortality. Populations with slow growth rate and low mortality should, therefore, have the best fishery potential, while those with high growth rate and high mortality have a low fishery potential. Further, it is possible to judge the fishery potential of a population or its stage of exploitation from relatively simple measurements of mortality, growth, age structure, and maturity.

scholarly journals Influence of types of constitution on meat productivity bullets of Simmental breed

2021 ◽  
Vol 273 ◽  
pp. 02024
Author(s):  
Anatoly Shevkhuzhev ◽  
Vladimir Pogodaev ◽  
Dagir Smakuev
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Meat Products ◽  
Live Weight ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Cattle Breeding ◽  
Meat Productivity

The aim of the research was to establish quantitative and qualitative indicators of meat productivity of Simmental bull calves of various constitutional types when raised using the technology of beef cattle breeding. The maximum growth rate and the highest yield of meat products were obtained from Simmental bulls of the meat and dairy type when they were raised and fed according to the technology of beef cattle breeding. Receiving from the mothers for 205 days of the sucking period more fatty milk, they gave 1250 g of gain per day and reached 289.7 kg of live weight by the cut. Having retained a high growth rate in the future, they at the final fattening gave 1321 g of gain per day and at 20 months the live weight was 659.3 kg. The superiority of Simmentals over analogues was natural by 3.4–13.3% by weight of the steamed carcass, by 0.4–1.8% in slaughter yield, by 1.4–11.1 kg in terms of the amount of pulp in the carcass and pulp per bones by 0.1–0.3 kg, protein in meat by 0.12; 1.19; 2.59 kg and the amount of energy in the pulp by 0.14; 0.44; 1.75 MJ. Simmental bulls of the meat and dairy type also have a high ability to transform protein and feed energy into protein and energy from the pulp of the carcass.

Comparison of Actual and Potential Growth Rates of Brown Trout (Salmo trutta) in Natural Streams Based on Bioenergetic Models

1989 ◽  
Vol 46 (6) ◽  
pp. 1067-1076 ◽  
Author(s):  
Richard J. Preall ◽  
Neil H. Ringler
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Specific Growth ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Dominant Feature ◽  
Natural Streams ◽  
Brown Trout Salmo Trutta

A ratio of specific growth rate to predicted maximum growth rate was employed as an ecological growth coefficient (EGC) in identifying major determinants of growth for brown trout, Salmo trutta, in natural streams. The coefficient may be more useful than specific growth rate when comparing trout populations from streams having diverse characteristics, since it accounts for the quantitative effects of stream temperature and mean trout weight. The maximum growth rate was generated by translating Elliott's bioenergetic equations into computer models applicable to fish weighing 5–300 g and to stream temperatures of 3.8–21.7 °C. EQMAX is the simpler model and generates only maximum growth rate. TROUT estimates the maximum ration size, maximum growth rate, and a variety of bioenergetic parameters. The EGC for Age I + trout ranged from 60 to 90% in three central New York streams. A relatively low EGC (30–60%) observed for Age II + trout in one stream may have been due to the inefficiency of feeding on small invertebrates. Temperature appears to be a dominant feature governing trout growth in streams. The bioenergetic models may provide useful predictions of the effects of foraging on prey communities by brown trout.

Seasonal Variations in the Growth Rate, Thyroid Gland Activity and Food Reserves of Brown Trout (Salmo Trutta Linn.)

1955 ◽  
Vol 32 (4) ◽  
pp. 751-764
Author(s):  
D. R. SWIFT
Keyword(s):  
Growth Rate ◽  
Thyroid Gland ◽  
Brown Trout ◽  
Seasonal Variations ◽  
Salmo Trutta ◽  
Maximum Growth ◽  
Liver Glycogen ◽  
Maximum Growth Rate ◽  
Thyroid Activity ◽  
Food Reserves

1. Seasonal variations in the growth rate, food reserves and activity of the thyroid gland of hatchery-reared brown trout have been investigated. 2. Two peaks of maximum growth rate were found, in spring and autumn. A marked depression of rate occurred during midsummer and winter. 3. Fat which was laid down along the mesenteries and pyloric caecae was found to be the main food reserve. Glycogen was found in small quantities in the liver and muscle. The composition of the muscle and liver was constant except for an autumnal fall in the female liver glycogen level. The fat reserves reached a peak of 23% by weight of the gut wall during July then fell to 5% in autumn. 4. Maturation of the gonads commenced in females in June and in males in July and was completed during October. The protein content of the ovary increased by 16%, and of the testis by 10%. The fat content of the ovary increased by 3%. 5. A new method is described for the determination of thyroid activity in fish using radioactive iodine. Peak thyroid activity was found to occur in midsummer.

Development of High Growth Rate SiC Epi-Reactor with Controlled Thermal Gradient

2007 ◽  
Vol 556-557 ◽  
pp. 81-84
Author(s):  
Masahiko Ito ◽  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
L. Storasta
Keyword(s):  
Growth Rate ◽  
Thermal Gradient ◽  
Gas Flow ◽  
Flow Behavior ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Simulation Results ◽  
Growth Experiments

A vertical hot-wall type reactor, with a unique structure designed for controlling both gas flow behavior and thermal gradient (T/mm) on the susceptor surface, was developed. The simulation results indicate that depending on the height of the epitaxy room (h), the T/mm can be changed from a negative to a positive value. Preliminary epitaxial growth experiments resulted in a maximum growth rate of 51 μm/h, 4-inch area uniformity of σ/mean=1.7% for growth rate and σ/mean=21.5 % for doping concentration, and Z1/2 trap concentration of 9×1012 cm-3 at a growth rate of 43 μm/h.

scholarly journals CRECIMIENTO DEL CORAL ACROPORA PALMATA (LAMARCK, 1886) EN EL PARQUE NACIONAL NATURAL CORALES DEL ROSARIO, CARIBE COLOMBIANO.

2016 ◽  
Vol 25 ◽  
Author(s):  
Rocío Del Pilar García U. ◽  
Elvira M. Alvarado Ch. ◽  
Alberto Acosta M.
Keyword(s):  
Growth Rate ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Annual Growth ◽  
Acropora Palmata ◽  
Alizarin Red ◽  
X Ray ◽  
Measuring Techniques ◽  
Growth Bands ◽  
Northern Zone

The growth rate in ten months (September 1992 - july 1993) for 30 colonies of Acropora palmata along the northern zone of the Corales del Rosario national natural park, Colombian Caribbean, was determined. Three measuring techniques were used: by hand, by staining with alizarin red, and from growth bands by X ray photography. The annual growth estimate for the species in the Park was 5.2 ± 1.3 cm and was found inversely correlated to the size of the colony (lenght, width and height). The growth presented a spatial variation. The smallest growth was found at Caleta Island and the largest at Caribaru Island. The maximum growth rate was observed in the dry season (December-February). No significant differences were found between measurement by hand and by alizarin red. The X-ray technique showed that Acropora palmata does not present discernible annual growth bands.

scholarly journals Reproductive Behaviour in Pakistan: Insights from the Population, Labour Force, and Migration Survey 1979-80

1984 ◽  
Vol 23 (2-3) ◽  
pp. 207-223 ◽  
Author(s):  
Zeba A. Sathar ◽  
Mohammad Irfan
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Labour Force ◽  
High Growth ◽  
Reproductive Behaviour ◽  
Policy Formulation ◽  
High Growth Rate ◽  
Fertility Survey ◽  
Annual Growth Rate ◽  
And Migration

Pakistan, with a population of83 million at the 1981 census, ranks as the ninth largest nation in the world. Owing to the persistently high levels of fertility and the concomitant relatively low levels of mortality, Pakistan's population has registered an annual growth rate of about 3 percent over the last two decades. This high growth rate poses a problem to all those concerned with the effects of rapid population growth in the face of limited global resources. Although a slight decline in Pakistan's fertility had been recorded in 1975, it was considered to be of little significance and a phenomenon too recent to influence population growth [I). A 12•percent decline in fertility during the 1970- 75 period, as suggested by the Pakistan Fertility Survey (PFS) data, however, generated hopes that Pakistan may well be entering into an era of declining fertility. There is an urgent need to investigate whether this decline was real and whether it continued in the late Seventies. Answers to these queries are of paramount importance both for population related research and for policy formulation. In this context, the data collected for Studies in Population, labour Force, and Migration (PLM) - a PIDE/ILO-UNFPA project [5] - may be extremely useful.

The assessment of seasonal yield using some Stylosanthes guyanensis accessions in humid tropical and sub-tropical environments

1977 ◽  
Vol 17 (86) ◽  
pp. 425 ◽  
Author(s):  
LA Edye ◽  
WT Williams ◽  
RL Burt ◽  
B Grof ◽  
SL Stillman ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Growth Period ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Growth Patterns ◽  
Seasonal Growth ◽  
Seasonally Dry ◽  
Tropical Environments ◽  
Dry Tropics

The seasonal growth patterns of some S. guyanensis accessions were compared in three humid environments at South Johnstone (extended rainfall tropics), 'Heathlands' (seasonally dry tropics) and Cooroy (humid sub-tropics). The accessions were selected mainly for their productivity in previously described small mown sward experiments over three years at each site. Previous methods of presenting seasonal growth patterns are reviewed, and a new, simpler method of presentation is defined. Growth was highly seasonal at all sites. There was no growth during July to November at 'Heathlands' and Cooroy due to moisture and temperature limitations respectively. At South Johnstone growth was continuous but depressed in August and December with limitations due to both soil moisture and temperature: the maximum growth rate was 22 times the minimum growth rate. The accessions differed markedly in their growth patterns at each site. In general, the yield differences between accessions were greater at the beginning and end of the growing season than during the peak growth period. The highest yielding accessions at each site had high growth rates spread over a long period. The yield distribution and persistence of Q8231 and 46589C seemed superior to existing cultivars in tropical and sub-tropical environments respectively

Sign in / Sign up

Export Citation Format

Share Document