0000000000623083
AUTHOR
Angeles Esparcia
showing 4 related works from this author
Relationships between oxygen concentration and patterns of energy metabolism in the rotifer Brachionus plicatilis
1992
Abstract 1. 1. Activities of 10 enzymes and accumulation of two metabolites under experimental hypoxia were investigated in the rotifer Brachionus plicatilis . 2. 2. Pyruvate kinase (PK), lactate dehydrogenase (LDH), malic enzyme (ME), phosphoenolpyruvate carboxykinase (PEPCK), malate dehydrogenase (MDH) and fumarase (FUM) activities showed great increase at low oxygen levels. Alcohol dehydrogenase (ADH) activity was not detected. 3. 3. Alanine concentration showed an increase with low oxygen concentrations, while alanine aminotransferase (GTP) showed a slight activity increase with oxygen levels. The high alanine concentration was interpreted as enhanced proteolysis. 4. 4. Our results show…
Rotifer vertical distribution in a strongly stratified lake: a multivariate analysis
1998
The main source of variation of rotifer species distributions in lake Arcas-2, a small karstic lake near Cuenca (Spain), was explored by means of principal components factor (PCA) and canonical correlation (CCA) analyses. PCA was performed using rotifer densities and CCA using rotifer densities plus physical and chemical parameters. Factor 1 of PCA separated summer species from winter-spring species and Factor 2 accounted for the variation in the vertical profile. Three summer species with different food habits (Polyarthra dolichoptera, Hexarthra mira and Asplanchna girodi) were grouped together at the positive end of Factor 1, while Factor 2 separated the two hypolimnetic species (Filinia …
Vertical distribution of planktonic rotifers in a karstic meromictic lake
1993
Vertical distribution of planktonic rotifers is described in relation to temperature and oxygen in Lake La Cruz, a single-doline, closed karstic lake (121 m diameter and 25 m maximum depth) which shows iron meromixis. Samples were taken by peristaltic pumping at 10 cm depth intervals in the oxycline zone from June 1987 to September 1988. A model of rotifer vertical structure in stratified lakes is proposed. Rotifers concentrate their populations at the depths with intense gradients. As stratification develops some rotifer populations show a downward migration following the thermocline and some others show an upward migration following the oxycline. The production-respiration balance in the …
Brachionus plicatilis tolerance to low oxygen concentrations
1989
Tolerance to low oxygen concentrations is expected in Brachionus plicatilis, a rotifer adapted to live in saline warm waters. The population dynamics of a clone of this species, isolated from an endorreic saline lake, was studied under controlled laboratory conditions. Although their growth and metabolism is extremely reduced, B. plicatilis populations are able to maintain relatively high-density populations (a mean of 35 ind ml−1) in oxygen concentrations below 1 mgl−1, for more than one month. Major features of population growth related to oxygen are discussed.