Ingestion-Limited Growth of Aquatic Animals: The Case for Blackman Kinetics

1982 ◽  
Vol 39 (12) ◽  
pp. 1585-1595 ◽  
Author(s):  
Richard E. Condrey
Keyword(s):  
Growth Rate ◽  
Linear Relationship ◽  
Ingestion Rate ◽  
Growth Efficiency ◽  
Published Data ◽  
Limited Growth ◽  
Aquatic Animals

The published data on ingestion-limited growth in aquatic animals is shown to be consistent with Blackman kinetics. As such, if ingestion limits growth rate there is a linear relationship between growth and ingestion from starvation to satiation. If, however, growth is limited by some factor other than ingestion rate, there is no increase in growth rate with increasing ingestion rate.Key words: ingestion, growth, growth efficiency, Blackman kinetics

Effect of growth rate on the physiological rates of a chemostat-grown rotifer Encentrum linnhei

1988 ◽  
Vol 68 (1) ◽  
pp. 165-177 ◽  
Author(s):  
J. M. Scott
Keyword(s):  
Growth Rate ◽  
Oxygen Consumption ◽  
Steady State ◽  
Respiration Rate ◽  
Clearance Rate ◽  
Ingestion Rate ◽  
Physiological State ◽  
Growth Efficiency ◽  
Theoretical Figure ◽  
Marine Rotifer

The physiological rates of a normally omnivorous marine rotifer, Encentrum linnhei, were measured under the steady-state chemostat conditions in which the physiological state of the food-algae was kept constant whilst the rotifer growth rate was changed to preset levels. The specific clearance rate ranged between 50 and 100 μl/μg rotifer C/day (1.5–3.0 μ/rot/day) and varied hyperbolically with growth rate, a similar curve was obtained with the specific ingestion rate which varied between 1–2 μg C/μg rot C/day. A mean respiration rate of 0.45 μg C/μg rot C/day was obtained from oxygen consumption measurements. About 60‰ of ingested energy was found to be egested as paniculate matter and 9–4 °0 dissipated as heat, the latter comparing with a theoretical figure of 4–5‰.From rates, transfer efficiencies were obtained giving a mean net growth efficiency (K2) of 38‰ and a mean overall growth efficiency (K1 of 15‰. A curvilinear increase of Kl with growth rate contrasts with linear and hyperbolic responses found with brachionid rotifers.

Effects of lasalocid and protein levels on feed intake and growth rate of Awassi lambs

1997 ◽  
Vol 1997 ◽  
pp. 187-187
Author(s):  
M. M. Muwalla ◽  
M. Y. Harb ◽  
T. F. Crosby
Keyword(s):  
Growth Rate ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Published Data ◽  
Growth Promoter ◽  
Feed Conversion ◽  
Protein Levels ◽  
Feedlot Lambs ◽  
Lamb Growth ◽  
Awassi Lambs

Lasalocid is a polyether antibiotic derived from the fermentation of streptomyces lasaliensis used as a coccidiostat in sheep. There are varying literature reports on lamb growth rate and feed intake when lasalocid is included in the diet of feedlot lambs. While some reports have shown that lasalocid enhances feed efficiency in ruminants by decreasing feed intake and either maintaining or improving rate of gain others indicate that lasalocid did not have any effect on lamb growth rates or feed efficiency (Stobart et al., 1987). Also, when lasalocid was fed to Chios lambs, growth rate was increased but there was no improvement in feed conversion efficiency (Hadjipanayiotou et al., 1988). There are no published data in the literature relating to the use of lasalocid as a growth promoter in the Awassi breed of sheep fed complete diets and the purpose of this study was to investigate the effect of lasalocid with two levels of protein on the growth rate and feed efficiency of weaned male and female Awassi lambs.

scholarly journals Threat of plastic pollution to seabirds is global, pervasive, and increasing

2015 ◽  
Vol 112 (38) ◽  
pp. 11899-11904 ◽  
Author(s):  
Chris Wilcox ◽  
Erik Van Sebille ◽  
Britta Denise Hardesty
Keyword(s):  
Risk Model ◽  
Ingestion Rate ◽  
Empirical Studies ◽  
Global Scale ◽  
Marine Debris ◽  
Published Data ◽  
Plastic Pollution ◽  
Anthropogenic Pressures ◽  
Seabird Species ◽  
Spatial Risk

Plastic pollution in the ocean is a global concern; concentrations reach 580,000 pieces per km2 and production is increasing exponentially. Although a large number of empirical studies provide emerging evidence of impacts to wildlife, there has been little systematic assessment of risk. We performed a spatial risk analysis using predicted debris distributions and ranges for 186 seabird species to model debris exposure. We adjusted the model using published data on plastic ingestion by seabirds. Eighty of 135 (59%) species with studies reported in the literature between 1962 and 2012 had ingested plastic, and, within those studies, on average 29% of individuals had plastic in their gut. Standardizing the data for time and species, we estimate the ingestion rate would reach 90% of individuals if these studies were conducted today. Using these results from the literature, we tuned our risk model and were able to capture 71% of the variation in plastic ingestion based on a model including exposure, time, study method, and body size. We used this tuned model to predict risk across seabird species at the global scale. The highest area of expected impact occurs at the Southern Ocean boundary in the Tasman Sea between Australia and New Zealand, which contrasts with previous work identifying this area as having low anthropogenic pressures and concentrations of marine debris. We predict that plastics ingestion is increasing in seabirds, that it will reach 99% of all species by 2050, and that effective waste management can reduce this threat.

Energy Dynamics of the Eutrophic Chironomid Chironomus plumosus f. semireductus from the Bay of Quinte, Lake Ontario

1980 ◽  
Vol 37 (8) ◽  
pp. 1254-1265 ◽  
Author(s):  
Ora E. Johannsson
Keyword(s):  
Growth Rate ◽  
Feeding Rate ◽  
Assimilation Efficiency ◽  
Growth Efficiency ◽  
Time Of Day ◽  
Organic Content ◽  
Algal Community ◽  
Instantaneous Growth Rate ◽  
Larval Size ◽  
Instantaneous Growth

Relationships between feeding rate, temperature, body size, and time of day were investigated and collated with seasonal assimilation efficiencies of in situ chironomids to construct a picture of chironomid energetics over the year. Temperature controlled feeding rate, and larval size and time of day exerted no effect. The temperature optimum plateaued between 22.0 and 24.5 °C, decreasing logarithmically outside this range. Both assimilation efficiency (AE) and organic content of the food varied seasonally, but were not correlated. Periods of high AE corresponded with the latter part of Melosira or Melosira–Stephanodiscus blooms, while periods of low AE occurred between diatom blooms and during the late summer blue-green bloom. Consequently, growth fluctuated throughout the year, being a result of the interaction of temperature and AE. Anabolic processes dominated at AE greater than 3.5%. Maximum net growth efficiency (NGE) was attained when AE ≥ 6% and temperature ≥ 15 °C. NGE was more sensitive to changes in AE than temperature. Instantaneous growth rate, however, was more sensitive to changes in temperature. Daily ingestion (mg) exceeded body weight by as much as 460–480%, which equals the sediment-processing capacity of freshwater detritivores.Key words: chironomid, feeding rate, assimilation efficiency, instantaneous growth rate, net growth efficiency, algal community, Bay of Quinte

scholarly journals Microcredits for Sustainable Development of Small Ukrainian Enterprises: Efficiency, Accessibility, and Government Contribution

2020 ◽  
Vol 12 (15) ◽  
pp. 6184 ◽  
Author(s):  
Olexandr Yemelyanov ◽  
Tetyana Petrushka ◽  
Anastasiya Symak ◽  
Olena Trevoho ◽  
Anatolii Turylo ◽  
...  
Keyword(s):  
Growth Rate ◽  
Sustainable Development ◽  
Linear Relationship ◽  
Labor Productivity ◽  
Small Businesses ◽  
State Support ◽  
Time Intervals ◽  
The Sustainable Development ◽  
Methodological Approaches ◽  
The Creation

The purpose of the study was to assess the efficiency and accessibility of microcredits for small Ukrainian enterprises and to justify the feasibility of strengthening government contributions in lending to ensure the sustainable development of small businesses. Indicators for evaluating the efficiency and accessibility of microcredits are systematized. Methodological approaches to assessing the efficiency of lending for the creation and development of microenterprises have been improved. A model for evaluating the efficiency of microcredits aimed at the survival of microenterprises in a deteriorating environment was developed. It has been revealed that the level of efficiency of microcredit creation for firms in some time intervals depends quadratically on the share of microcredits in the total amount of funds directed to the creation of firms. A linear relationship between the relative amount of credit received and the growth rate of firms’ assets has also been established. However, there is no significant impact of the microcredit’s amount on labor productivity. A method has been developed for evaluating the budgetary efficiency of microcredits when such a lending is carried out using funds from state or local budgets. It was found that improving these lending conditions through budget financing can significantly increase its attractiveness for microenterprises without significantly reducing the budgetary efficiency of microcredits. This article substantiates the need to strengthen state support for microcrediting of small Ukrainian enterprises in the context of the COVID-19 pandemic.

Isozyme variation, morphology, and growth response to temperature in Pythium irregulare

1997 ◽  
Vol 75 (12) ◽  
pp. 2073-2081 ◽  
Author(s):  
D. J. S. Barr ◽  
S. I. Warwick ◽  
N. L. Desaulniers
Keyword(s):  
Growth Rate ◽  
Pythium Ultimum ◽  
Morphological Characters ◽  
Published Data ◽  
Pythium Irregulare ◽  
Analysis Group ◽  
Wide Range ◽  
Pythium Sylvaticum ◽  
Group A ◽  
Group B

Isozyme-based genetic diversity, morphological characters, and growth rate at different temperatures were compared in a worldwide collection of 125 isolates presumed to be Pythium irregulare Buisman. The isozyme data was analysed with previously published data for Pythium ultimum Trow and Pythium sylvaticum Campbell & Hendrix. UPGMA cluster analysis yielded a dendrogram with four distinct groups: P. ultimum, P. sylvaticum, and two for P. irregulare. Putative P. irregulare isolates were separated into 33 multilocus genotypes defined by 11 isozyme loci: group A contained 116 isolates in 25 genotypes, and group B, 8 isolates in 7 genotypes. One genotype with a single isolate was determined as P. sylvaticum. Based on the isozyme analysis, group B was considered a distinct taxonomic entity from group A, but lacked any unique morphological character. There was a wide range in oogonium and oospore sizes among different isolates of P. irregulare, with those in group B generally being larger. Some isolates in group A had well developed oogonial spines, but others were essentially spineless, whereas all those in group B were spineless. Both groups A and B contained isolates with distinctly aplerotic oospores and others with essentially plerotic oospores. Antheridial number and shape were highly variable both within and among isolates in the two groups. Growth rate over a range of temperatures varied among isolates in both groups and was not a reliable taxonomic criterion. The irregular shape of oogonia and, when present, oogonial spines were the only reliable characters for distinguishing P. irregulare isolates from other taxa. Key words: taxonomy, Oomycetes, Pythiaceae, Pythium ultimum, Pythium sylvaticum.

Sign in / Sign up

Export Citation Format

Share Document