scholarly journals Effects of Chicken Manure Extract on the Population Growth, Mixis Induction and Body Size of the Freshwater Rotifer Brachionus angularis Gosse 1851

2015 ◽  
Vol 28 (4) ◽  
Author(s):  
ERICK OCHIENG OGELLO ◽  
ATSUSHI HAGIWARA
Keyword(s):  
Body Size ◽  
Population Growth ◽  
Chicken Manure ◽  
Brachionus Angularis

Effect of two microalgae concentrations on body size and egg size of the rotifer Brachionus calyciflorus

Biologia ◽  
2008 ◽  
Vol 63 (3) ◽  
Author(s):  
Abdolmohammad Kennari ◽  
Nasrollah Ahmadifard ◽  
Maryam Kapourchali ◽  
Jafar Seyfabadi
Keyword(s):  
Body Size ◽  
Population Growth ◽  
Egg Size ◽  
Scenedesmus Obliquus ◽  
Exponential Phase ◽  
The Body ◽  
Brachionus Calyciflorus ◽  
Food Level ◽  
Chlorella Sp ◽  
Rotifer Brachionus Calyciflorus

AbstractThe rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 106 cells ml−1). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed on higher densities of Chlorella sp. (10 × 106 cells ml−1) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 106 cells ml−1). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size.

scholarly journals Linking individual phenotype to density-dependent population growth: the influence of body size on the population dynamics of malaria vectors

2011 ◽  
Vol 278 (1721) ◽  
pp. 3142-3151 ◽  
Author(s):  
Tanya L. Russell ◽  
Dickson W. Lwetoijera ◽  
Bart G. J. Knols ◽  
Willem Takken ◽  
Gerry F. Killeen ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Population Growth ◽  
Vector Control ◽  
Anopheles Gambiae ◽  
Phenotypic Expression ◽  
Phenotypic Traits ◽  
Density Dependent ◽  
Individual Fitness ◽  
The Impact

Understanding the endogenous factors that drive the population dynamics of malaria mosquitoes will facilitate more accurate predictions about vector control effectiveness and our ability to destabilize the growth of either low- or high-density insect populations. We assessed whether variation in phenotypic traits predict the dynamics of Anopheles gambiae sensu lato mosquitoes, the most important vectors of human malaria. Anopheles gambiae dynamics were monitored over a six-month period of seasonal growth and decline. The population exhibited density-dependent feedback, with the carrying capacity being modified by rainfall (97% w AIC c support). The individual phenotypic expression of the maternal ( p = 0.0001) and current ( p = 0.040) body size positively influenced population growth. Our field-based evidence uniquely demonstrates that individual fitness can have population-level impacts and, furthermore, can mitigate the impact of exogenous drivers (e.g. rainfall) in species whose reproduction depends upon it. Once frontline interventions have suppressed mosquito densities, attempts to eliminate malaria with supplementary vector control tools may be attenuated by increased population growth and individual fitness.

scholarly journals The scaling of expansive energy under the Red Queen predicts Cope’s Rule

2019 ◽  
Author(s):  
Indrė Žliobaitė ◽  
Mikael Fortelius
Keyword(s):  
Body Size ◽  
Population Growth ◽  
Body Mass ◽  
Limiting Factor ◽  
Large Species ◽  
Small Species ◽  
Evolutionary Advantage ◽  
Zero Sum ◽  
The Red Queen ◽  
Cope’S Rule

AbstractThe Red Queen’s hypothesis portrays evolution as a never-ending competition for expansive energy, where one species’ gain is another species’ loss. The Red Queen is neutral with respect to body size, implying that neither small nor large species have a universal competitive advantage. The maximum population growth in ecology; however, clearly depends on body size – the smaller the species, the shorter the generation length, and the faster it can expand. Here we ask whether, and if so how, the Red Queen’s hypothesis can accommodate a spectrum of body sizes. We theoretically analyse scaling of expansive energy with body mass and demonstrate that in the Red Queen’s zero-sum game for resources, neither small nor large species have a universal evolutionary advantage. We argue that smaller species have an evolutionary advantage only when resources in the environment are not fully occupied, such as after mass extinctions or following key innovations allowing expansion into freed up or previously unoccupied resource space. Under such circumstances, we claim, generation length is the main limiting factor for population growth. When competition for resources is weak, smaller species can indeed expand faster, but to sustain this growth they also need more resources. In the Red Queen’s realm, where resources are fully occupied and the only way for expansion is to outcompete other species, acquisition of expansive energy becomes the limiting factor and small species lose their physiological advantage. A gradual transition from unlimited resources to a zero-sum game offers a direct mechanistic explanation for observed body mass trends in the fossil record, known as Cope’s Rule. When the system is far from the limit of resources and competition is not maximally intense, small species take up ecological space faster. When the system approaches the limits of its carrying capacity and competition tightens, small species lose their evolutionary advantage and we observe a wider range of successful body masses, and, as a result, an increase in the average body mass within lineages.

scholarly journals Kajian Budidaya Daphnia magna Menggunakan Air Rebusan Kedelai Dan Air Cucian Beras

PELAGICUS ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 45
Author(s):  
Hernika Simanjuntak ◽  
Ernik Yuliana ◽  
Sinar Pagi Sektiana
Keyword(s):  
Escherichia Coli ◽  
Population Growth ◽  
Daphnia Magna ◽  
Design Method ◽  
Chicken Manure ◽  
Natural Food ◽  
Feed Water ◽  
E Coli ◽  
Significant Difference ◽  
Boiled Water

ABSTRAKDaphnia magna memiliki banyak keunggulan sebagai pakan alami pada budidaya ikan fase larva. Tujuan penelitian ini adalah membandingkan pertumbuhan Daphnia magna pada budidaya dengan menggunakan beberapa sumber air pupuk/pakan. Penelitian ini dilakukan secara eksperimental dengan metode Rancangan Acak Lengkap (RAL) dengan perlakuan yaitu pemberian pupuk pakan: kotoran ayam, air cucian beras, dan air rebusan kedelai, masing-masing pada konsentrasi 2%, 5% dan 10% dengan 3 kali pengulangan. Analisis data yang digunakan adalah uji statistik ANOVA dan dilanjutkan dengan uji beda nyata terkecil (BNT). Hasil penelitian menunjukkan bahwa pertumbuhan populasi yang lebih baik adalah dengan penambahan pakan/pupuk air rebusan kedelai dengan konsentrasi berturut-turut 10%, 5%, dan 2%. Hasil uji ANOVA menunjukkan perbedaan yang siginifikan antar perlakuan, namun tidak berbeda signifikan pada penggunaan konsentrasi yang berbeda. Hasil uji BNT menunjukkan bahwa air rebusan kedelai konsentrasi 5% dan 10% memberikan respon yang lebih baik dengan rata-rata pertumbuhan populasi 346 ekor dan 534 ekor. Hasil pengujian kandungan protein dan lemak didapatkan hasil bahwa air rebusan kedelai lebih tinggi dibanding yang lainnya yaitu rata-rata sebesar 2,50% dan 5,77%. Pengujian kandungan Escherichia coli didapatkan hasil jika semua perlakuan menunjukkan kandungan E. coli yang negatif.ABSTRACTDaphnia magna has many advantages as natural food in larval stage fish culture. This study aims to compare the growth of Daphnia magna in cultivation using several sources of fertilizer/feed water. This research was conducted experimentally with a completely randomized design method with the treatment of feeding fertilizer: chicken manure, rice washing water, and soy boiled water, each at a concentration of 2%, 5% and 10% with 3 repetitions. The data analysis used was the ANOVA statistical test and continued with the least significant difference test (LSD). The results indicated that the better population growth was the addition of soybean boiled feed/water fertilizer with concentrations of 10%, 5%, and 2%, respectively. The results of the ANOVA test indicated that was a significant difference between treatments, but not significantly different at the use of different concentrations. LSD test results indicated that soybean boiled water with a concentration of 5% and 10% gave a better response with an average population growth of 346 and 534 individuals. The results of testing the protein and fat content showed that the cooking water for soybeans was higher than the others, namely 2.50% and 5.77%, respectively. The test for Escherichia coli content was obtained if all treatments showed negative E. coli content.

scholarly journals Body size of female calves and natality rates of known-aged females in two adjacent Alaskan caribou herds, and implications for management

Rangifer ◽  
2003 ◽  
Vol 23 (5) ◽  
pp. 203 ◽  
Author(s):  
Patrick Valkenburg ◽  
Robert W. Tobey ◽  
Robert W. Tobey ◽  
Bruce W. Dale ◽  
Bruce W. Dale ◽  
...  
Keyword(s):  
Body Size ◽  
Population Growth ◽  
Body Mass ◽  
Real Option ◽  
Rangifer Tarandus ◽  
Herd Size ◽  
Adult Females ◽  
Potential Population ◽  
Newborn Calves ◽  
Natality Rate

We studied body mass of female calves and natality rate of adult females in two adjacent Interior Alaskan caribou (Rangifer tarandus granti) herds during 1991-2001. Mass of newborn calves was similar in both herds, but Delta calves gained significantly more mass over summer than Nelchina calves. In contrast, Nelchina calves consistently maintained their mass during winter while Delta calves lost mass. Metatarsus length was similar in both herds in 4-month-old and 10-month-old calves, and it increased over winter in both herds. Natality rates of females &gt;3 years old were consistently higher in the Delta Herd than in the Nelchina Herd, primarily because natality in 3- to 5-year-old Nelchina females was low. Although body mass of Delta Herd calves consistently declined over winter, we concluded that nutrition was not significantly limiting herd growth. Managers are more likely to maximize harvest by maintaining the Delta Herd near its present size (i.e., 3500), or allowing it to increase only slightly. The only real option for increasing harvestable surpluses of caribou in the Delta Herd is reducing predation during calving and summer. In contrast, we conclude that summer nutrition significantly limits potential population growth and body mass in the Nelchina Herd, and managers are more likely to maximize harvest by maintaining herd size at or below 30 000 than by allowing the herd to grow to near historical highs (i.e., 60 000-70 000).

scholarly journals Rapid plastic shifts in body size precede and determine population growth

2021 ◽  
Author(s):  
Jean Philippe Gibert ◽  
Ze-Yi Han ◽  
Daniel J Wieczynski ◽  
Andrea Yammine
Keyword(s):  
Time Series ◽  
Body Size ◽  
Population Density ◽  
Population Growth ◽  
Carrying Capacity ◽  
Rapid Evolution ◽  
The Other ◽  
Phenotypic Change ◽  
Ecological Processes ◽  
Ecological Dynamics

1. Body size is a fundamental trait linked to many ecological processes-from individuals to ecosystems. Although the effects of body size on metabolism are well-known, how body size influences, and is influenced by, population growth and density is less clear. Specifically, 1) whether body size, or population dynamics, more strongly influences the other, and, 2) whether observed changes in body size are due to plasticity or rapid evolutionary change, are not well understood. 2. Here, we address these two issues by experimentally tracking population density and mean body size in the protist Tetrahymena pyriformis as it grows from low density to carrying capacity. We then use state-of-the-art time-series analyses to infer the direction, magnitude, and causality of the link between body size and ecological dynamics. Last, we fit two alternative dynamical models to our empirical time series to assess whether plasticity or rapid evolution better explains changes in mean body size. 3. Our results clearly indicate that changes in body size precede and determine changes in population density, not the other way around. We also show that a model assuming that size changes via plasticity more parsimoniously explains these observed coupled phenotypic and ecological dynamics than one that assumes rapid evolution drives changes in size. 4. Together these results suggest that rapid, plastic phenotypic change not only occurs well within ecological timescales but may even precede -and causally influence- ecological dynamics. Furthermore, large individuals may be favored and fuel high population growth rates when population density is low, but smaller individuals may be favored once populations reach carrying capacity and resources become scarcer. Thus, rapid plastic changes in functional traits may play a fundamental and currently unrecognized role in familiar ecological processes like logistic population growth.

scholarly journals Growth of Spirulina platensis Cultured with Inorganic Fertilizer (Urea, TSP and ZA) and Chicken Manure

2007 ◽  
Vol 4 (1) ◽  
pp. 41 ◽  
Author(s):  
N.B.P Utomo ◽  
. Winarti ◽  
A. Erlina
Keyword(s):  
Population Growth ◽  
Spirulina Platensis ◽  
Crude Protein ◽  
Nutrient Content ◽  
The Other ◽  
Inorganic Fertilizer ◽  
Chicken Manure ◽  
Other Hand ◽  
Inorganic Medium ◽  
Population Maximum

<p>This experiment was conducted to compare the effectiveness of inorganic fertilizer and chicken manure on population growth and nutrient content of <em>Spirulina platensis</em>. It was found that <em>Spirulina platensis</em> cultured in inorganic medium reached a maximum population on day-9 with a density of 614.77x10<sup>3</sup> Sin/ml, containing 56.39% of crude protein and 17.92% of lipid. On the other hand, <em>Spirulina platensis</em> cultured in 250 ppm of chicken manure reached a maximum population on day-4 with a density of 434.32x10<sup>3 </sup>Sin/ml, containing 45.39% of crude protein and 12.50% of lipid.</p> <p>Keywords: spirulina, <em>Spirulina platensis</em>, culture, inorganic fertilizer, chicken manure, population maximum</p> <p> </p> <p>ABSTRAK</p> <p>Penelitian ini dilakukan untuk membandingkan efektivitas pupuk inorganik (urea, TSP dan ZA) dan kotoran ayam terhadap pertumbuhan dan kandungan nutrien <em>Spirulina platensis</em>.  Hasil penelitian menunjukkan bahwa <em>Spirulina platensis</em> dikultur menggunakan pupuk inorganik mencapai puncak populasi pada hari ke-9 dengan kepadatan 614,77x10<sup>3</sup> Sin/ml, mengandungkan protein kasar 56,39% dan lemak 17,92%. Sementara itu, <em>Spirulina platensis</em> dikultur menggunakan kotoran ayam 250 ppm mencapai puncak populasi pada hari ke-4 dengan kepadatan 434,32x10<sup>3</sup> Sin/ml, kandungan protein kasar 45,39% dan lemak 12,50%.</p> <p>Kata kunci: spirulina, <em>Spirulina platensis</em>, kultur, pupuk inorganik, kotoran ayam, populasi maksimal</p>

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