Cirino et al.:   Laboratory culture of Ciona

Appendix 3: Notes on the physico-chemical parameters

  1. Temperature is nearly constant (21 °C); we regulate it by cooling or heating the culture seawater as needed. Since temperature is a very important parameter affecting the filtration rate, and, consequently, animal growth and sexual maturation, we made several trials to find the right temperature range to apply to our system. According to our results this range is 20 - 22 °C.

  2. The pH is always above 8.0 and salinity is about 38 ppt.

  3. Oxygen concentration ranges between 6 and 7 mg per liter.

  4. Concentrations of ammonia (NH3-N) and nitrite (NO2-N) never exceed 0.01 mg/l.

  5. Light conditions follow the ambient photoperiod. The tank walls are of tinted glass, which dims direct light.