Osmoregulatory capacity of the shrimp Litopenaeus vannamei at different temperatures and salinities, and optimal culture environment

Osmoregulation in Litopenaeus vannamei was studied in a factorial experiment at four temperatures (20, 24, 28 and 32 degrees C) and six salinities (10, 16, 22, 28, 34 and 40 per thousand). The isosmotic related points for 20, 24, 28, and 32 degrees C were 754, 711, 822, and 763 mmol/kg, respectively. This species hyperregulates between at salinities of 10 and 20 per thousand and hyporegulates between 20 and 40 per thousand. The isosmotic point in L. vannamei exposed to constant salinities changed in relation to temperature from 717 to 823 mmol/kg. For these experimental conditions, the T-S combination of 32 degrees C and 28 per thousand produced the best growth.

La respuesta osmorreguladora de Litopenaeus vannamei se estudió en un experimento factorial con cuatro temperaturas (20, 24, 28 y 32 ºC) y seis salinidades (10, 16, 22, 28, 34 y 40 ‰). Los puntos isosmóticos relacionados para 20, 24, 28, y 32 ºC fueron 754, 711, 822, y 763 mmol/kg, respectivamente. Esta especie hiperregula dentro del intervalo de 10 y 20 ‰ e hiporegula entre 20 y 40 ‰. El punto isosmótico de L. vannamei expuesto a salinidades constantes cambia en relación a la temperatura desde 717 a 823 mmol/kg. Para estas condiciones experimentales, la combinación T-S de 32 ºC y 28 ‰ produjo el mejor crecimiento.

Spin relaxation by transient monopolar and bipolar optical orientation.

We have used two-color time-resolved spectroscopy to measure the relaxation of electron spin polarizations in a bulk semiconductor. The circularly polarized pump beam induces a polarization either by direct excitation from the valence band, or by free-carrier (Drude) absorption when tuned to an energy below the band gap. We find that the spin relaxation time, measured with picosecond time resolution by resonant induced Faraday rotation in both cases, increases in the presence of photogenerated holes. In the case of the material chosen, n-InSb, the increase was from 14 to 38 ps.

Osmoregulatory capacity of the shrimp Litopenaeus vannamei at different temperatures and salinities, and optimal culture environment.

Osmoregulation in Litopenaeus vannamei was studied in a factorial experiment at four temperatures (20, 24, 28 and 32 degrees C) and six salinities (10, 16, 22, 28, 34 and 40 per thousand). The isosmotic related points for 20, 24, 28, and 32 degrees C were 754, 711, 822, and 763 mmol/kg, respectively. This species hyperregulates between at salinities of 10 and 20 per thousand and hyporegulates between 20 and 40 per thousand. The isosmotic point in L. vannamei exposed to constant salinities changed in relation to temperature from 717 to 823 mmol/kg. For these experimental conditions, the T-S combination of 32 degrees C and 28 per thousand produced the best growth.