Biomaterial Database

[Population growth rate of the rotifer Brachionus rotundiformis (Rotifera: Brachionidae) in a two-stage chemostat]. 2008

María I Cabrera

Departamento de Biología, Facultad Experimental de Ciencias, Universidad del Zulia, Laboratorio de Modelos Ecológicos y Tramas Tróficas, Apdo. Postal 10 552, Maracaibo, Venezuela. gaiagua@yahoo.com

The population growth rate of the rotifer Brachionus rotundiformis (Rotifera: Brachionidae) in two-stage chemostat. The population growth rates of Brachionus rotundiformis were estimated in two-stage chemostat cultures. Chlorella sorokiniana was supplied continuously from a steady state culture growing with constant illumination on limiting nitrate. Rotifer growth in the second stage was limited by the rate of algal supply. The algal supply rate and rotifer population growth rate were determined by the second-stage dilution rate. The maximum population growth rate in the transient state of B. rotundiformis (1.96 day(-1)) was observed at 2.5 x 10(6) cel/ml of the algae whereas in the steady state the maximum population growth rate (1.09 day(-1)) was similar to the point Hopf's bifurcation predicted by Fussmann and was observed at 1 x 10(6) cel/ml of the algae. In the transient state, the rotifer's growth rate increased and the duplication time decreased at higher algal concentrations, until reaching a peak where the population growth rate begins to decrease. In the steady state, the opposite was true. The growth rates observed in this work are among the highest recorded for this rotifer in continuous cultures.

UI	MeSH Term	Description	Entries
D011156	Population Density	Number of individuals in a population relative to space.	Overpopulation,Population Size,Underpopulation,Densities, Population,Density, Population,Population Densities,Population Sizes
D011158	Population Growth	Increase, over a specific period of time, in the number of individuals living in a country or region.	Population Explosion,Baby Boom,Baby Bust,High Fertility Population,Natural Increase,Past Trends,Population Growth and Natural Resources,Population Size and Growth,Zero Population Growth,Baby Booms,Baby Busts,Explosion, Population,Explosions, Population,Growth, Population,High Fertility Populations,Increase, Natural,Increases, Natural,Natural Increases,Past Trend,Population Explosions,Population, High Fertility,Populations, High Fertility,Trend, Past,Trends, Past
D002708	Chlorella	Nonmotile unicellular green algae potentially valuable as a source of high-grade protein and B-complex vitamins.	Chlorellas
D004780	Environment, Controlled	A state in which the environs of hospitals, laboratories, domestic and animal housing, work places, spacecraft, and other surroundings are under technological control with regard to air conditioning, heating, lighting, humidity, ventilation, and other ambient features. The concept includes control of atmospheric composition. (From Jane's Aerospace Dictionary, 3d ed)	Clean Rooms,Laminar Air-Flow Areas,Controlled Environment,Area, Laminar Air-Flow,Clean Room,Controlled Environments,Environments, Controlled,Laminar Air Flow Areas,Laminar Air-Flow Area,Room, Clean
D005523	Food Supply	The production and movement of food items from point of origin to use or consumption.	Food Supply Chain,Chain, Food Supply,Food Supplies,Food Supply Chains,Supplies, Food,Supply Chain, Food,Supply Chains, Food,Supply, Food
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012403	Rotifera	A class of minute animals of the phylum Aschelminthes.	Rotiferas
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor