Studies on specific property of population growth of Moina rectirostris, Simocephalus vetuloides, Daphnia pulex forma schoedleri Stars were conducted under 28± 0.5℃ .
在28±0．5℃控温条件下,对直额裸腹溞(Moina rectirostris)、拟老年低额溞 (Simocephalus vetuloides)、细长型蚤状溞(Daphnia pulex forma schoedleri Stars)进行了种群增长特性的研究。
During the culture season (temperature 22.6-29.7℃), the generation time of the dominant species Strombidium sulcatum was 6.54-19.80h, population growth rate 0.035-0.106h -1 . The population growth of S. sulcatum was affacted by temperature and amount of food.
Rotifer can survive at pH 3. 5 ~ 11. 5, but the optimum pH for population growth is 8. 5. where the rotifer shows a maximum reproductive sped. and the absolute egg density is the highest (132 cells' ml-1 ).
The results demonstrate that ciliates can interrupt the normal population growth of bacteria, enhance breaking down organic pollutants and improving water quality.
Analysis of data showed that the ammonia accumulation was higher than that of the control during the equilibrium stage of ciliate population growth,and was significantly lower than in the control during the decaying stage either in Euplotes treatments with a range of 0 01-0 2 g/L glucose concentrations or in the Uronema treatments with a range of 0 05-0 2 g/L glucose concentrations.
The relationships between the temperature and the population growth rate of both QD and GZ strain were curvilinear, with the regression equation Y= 0.0009X2 - 0.0061X + 0.4090 and Y= - 0.0144X2 + 0.7412X - 8.3751, respectively.
When0. 02～5.00μg/ml of vitamin A is added tobaker's yeast suspension,the population growth rate R increases with the rising concentration ofvitamin A,and reaches the highest value(0.75)at the concentration of 5. 00μg/ml on the 4th day,which is 5. 6times high than that of the controlled group.
When the food concentration was 8.2453×10 6cells·ml -1 , the population growth rate reached it's maximum, 0.6085d -1 . Body size tended to enlarge with increasing food concentration.
A new class of competition models in which the population growth coefficients are represented by periodic delta-functions is designed.
Analysis of the available field and published data indicates a two-stage pattern of the population growth phase and a synchronous transition of wolf populations to this phase.
Selenium in concentrations of 0.01 and 0.5 mg/liter stimulated cell population growth, while the number of ultrastructural alterations was the same as in the control cells.
At a selenium concentrations of 1 mg/liter, cell population growth slightly decreased by the end of the experiment, and there was some increase in the number of cells with damaged organoids and in the number of completely destroyed cells.
salina, suppressing cell population growth and promoting extensive destructive changes.
The purpose of the present report is to study the population growth of a highly commercially exploited species, Hairtails, in its major distribution area in order to provide a ibasis for controlling the population dynamics and considering possible management measures.The specimens of the main population used for this study were collected in the northern East China Sea from May 1977 to June 1978, but some elder ones were the spaw-ners in 1976 and 1979, and specimens of other populations...
The purpose of the present report is to study the population growth of a highly commercially exploited species, Hairtails, in its major distribution area in order to provide a ibasis for controlling the population dynamics and considering possible management measures.The specimens of the main population used for this study were collected in the northern East China Sea from May 1977 to June 1978, but some elder ones were the spaw-ners in 1976 and 1979, and specimens of other populations were collected from 9 fishing grounds located in the South China Sea and the southern East China Sea as well as the Bohai Sea and Huangbai Sea in. recent years.Based on the study of the age, the measurement of the body and its otolith transverse section, the relative growth of otolith and population growth pattern as well as the weight-length relationship of this fish, the problem of geographical differences in population growth ih the northern Bast China Sea and elsewhere is discussed. The results of our study are summarized as follows :1.The otolith and (body growth of this fish are 'closely related to the form of the power function curve, so that the otoliih can be used for (back-calculating the fish growth.2.The females fish grows slightly faster than the males, but the growth differences between the sexes are not significant statistically.3.Based on the bimodal distribution of first ring radius of otolith and body length of young fish, it may be concluded that the Hairtails generally consist of two or three groups such as spring and summer and autumn broods, but so far as concerns the main population, it may be devided into two groups by the size of the first ring radius, the earlier-born group .(spring and summer broed, r>0.72 mm) and late-born group au tumn brood, r<0.72mm).4.The weight-length relationships of the main population (A+S) and its earlierborn group(S) and later-born group (A) are expressed in equations 19 - 21.5. The growth pattern of this fish could be expressed in equations 13-24.6.Growth in weight with age for this fish is determined also as a typically asby-metric sigmoid curve, the inflexion corresponding to maximum growth rate occurs at 3.26 age (3.17 for ealier-born group and 3.43 for later-born group). It has been observed that the majority of individuals in 1 age group has attained sexual maturity and all the males and females 'become sexually mature in 2 years. The significance of the infle-xion of the population growth equation by weight should be further netted because the size at instantaneous first capture providing the maximum yield generally lies at around this point.7.The increment and incremental rate of this fish in standard length and weight are described with dL/dt, d2L/dt2, dW/dt and d2W/dt2 curves respectively (F g. 2,4).8.The obvious growth difference in body length and weight between the earlier and later-born group is found only in first two years, but not so obvious in growon parameters such as the limiting body length, weight and inflexion of growth curve for weight.9.The geographical difference in population growth is found obvious orey between the populations of sub-tropical waters (the South China Sea) and temperate waters.10.The Hairtails have a more rapid growth rate than the Large Yelloy Croaker or the Small Yellow Croaker, and its long breeding period as well as the predt tory and mixed feeding habit account for its great productivity. While the number of the other two species of croakers are greatly reduced as a result of heavy fishing pressure., they are still present in significant amount to be the main fish stock of the fishing ground and their growth rate is get higher than years ago. If the fishing of the, last two lowest age, group can be postponed one or two years later, its population productivity may possibly be increased greatly. Thus, it is very promosing to have a further development of this fishery. .
Egg develpoment time and population growth of Brachionus calyciflorus were observed at constant temperature, and the production rate of the species was estimated with three different methods.
Midge larvals from fishing ponds were studied from Apr, 1986 to Jun 1987. Using the methods of collecting specimens with modified Peterson grab and the emergence traps, about two handreds sampling were carried out for the last two years. Specimens were extracted and identified. The data collected are used to show the annual fluctuations in the number of individuals in cohort md its biomass, to describe the population growth by the logistic equation, to determine the intrinsic rate of increase of the population,...
Midge larvals from fishing ponds were studied from Apr, 1986 to Jun 1987. Using the methods of collecting specimens with modified Peterson grab and the emergence traps, about two handreds sampling were carried out for the last two years. Specimens were extracted and identified. The data collected are used to show the annual fluctuations in the number of individuals in cohort md its biomass, to describe the population growth by the logistic equation, to determine the intrinsic rate of increase of the population, to estimate the various components of production for the population of larval of Chironomus attenuatus from Mar to Jun, 1987, in which the actual net production is 1412.33 g/m2 and to give the r'tio as 2.497 of the total production (P) of C.attenuatus to its biomass (B). It does support notice that the presence of fish predators are main reason for a pond's bcnthic decrease in abundance for the period Mny-Jun, 1987.
population growth
种群增长
查询“population growth”译词为用户自定义的双语例句
相关查询
2008 CNKI－中国知网