Search results for "Tetraselmis"
showing 4 items of 4 documents
Influence of the concentration of oxygen on the swimming path of Brachionus plicatilis (Rotifera)
1993
Brachionus plicatilis females were maintained for > 24 hours in water where the concentration of oxygen was precisely controlled (spherical flasks with ≥ 6 mg 1−1 or < 0.5 mg 1−1; food = dead Tetraselmis sp.). Each female was randomly taken from one flask and quickly placed in an observation chamber containing the same experimental conditions. The swimming path was videotaped (5 minutes); then the size of the female was measured. The tape was analyzed by automatic tracking (25 x, y coordinates of the center of the animal, in a 512 × 512 pixels space). The swimming path was analyzed for ~45 females in both treatments. The speed (mm s−1 body length−1) was calculated for all trajectories, or o…
Effects of salinity, temperature and food level on the demographic characteristics of the seawater rotifer Synchaeta littoralis Rousselet.
2001
A strain of the seawater species Synchaeta littoralis, isolated from a Spanish Mediterranean coastal salt marsh, was cultured in the laboratory and fed with the alga Tetraselmis sp. The effect of three salinities (25 per thousand, 30 per thousand and 35 per thousand), two temperatures (20 degrees C and 25 degrees C) and two food levels (75,000 and 150,000 cells ml(-1)) on demographic parameters was studied using a life table approach. Average lifespan (LS) ranged between 4.0 and 7.3 days, net reproductive rate (R(0)) between 4.2 and 9.1 offspring per female, and intrinsic growth rate (r) between 0.50 and 0.95 day(-1). Salinity and temperature had a significant negative effect (***p<0.001) o…
Improved Extraction Efficiency of Antioxidant Bioactive Compounds from Tetraselmis chuii and Phaedoactylum tricornutum Using Pulsed Electric Fields
2020
Pulsed electric fields (PEF) is a promising technology that allows the selective extraction of high-added value compounds by electroporation. Thus, PEF provides numerous opportunities for the energy efficient isolation of valuable microalgal bioactive substances (i.e., pigments and polyphenols). The efficiency of PEF-assisted extraction combined with aqueous or dimethyl sulfoxide (DMSO) solvents in recovering pigments and polyphenols from microalgae Tetraselmis chuii (T. chuii) and Phaeodactylum tricornutum (P. tricornutum) was evaluated. Two PEF treatments were applied: (1 kV/cm/400 pulses, 3 kV/cm/45 pulses), with a specific energy input of 100 kJ/kg. The total antioxidant capacity (TAC) …
Effects of temperature, salinity and food level on the life history traits of the marine rotifer Synchaera cecilia valentina, n. subsp.
1997
A strain of the marine rotifer Synchaeta cecilia valentina, n. subsp., isolated from the Hondo of Elche Spanish Mediterranean coastal lagoon at 22%o salinity, was cultured in the laboratory in 20 ml test tubes and fed with the alga Tetraselmis suecica. The effect of two temperatures (20 and 24°C), four salinities (20,25,30 and 37%o) and two food levels (15 000 and 25 000 cells ml-1) on the life history traits of this rotifer were studied in life tables performed with replicated individual cultures. Temper- ature and salinity had a significant negative effect (P < 0.001) on the average lifespan (LS) and on the number of offspring per female (RQ). The effect of food level on LS is unclear, wh…