Effect of irradiance and temperature on Chondracanthus chamissoi sporophytes

Chondracanthus chamissoi, commonly known as “yuyo” or “sea chicory”, has acquired great economic importance in recent years due to its potential as an aquaculture resource in Peru and Chile. For this reason, it is necessary to know the factors that affect its cultivation. With the aim of determining the effect of irradiance and temperature on the settlement and growth of C. chamissoi sporophytes, newly released carpospores were subjected to two levels of irradiance (35 and 70 µmol m^-2 s^-1) and three temperatures (18, 20 and 22 ºC) for 6 weeks. The number of settled carpospores was quantified 7 days after the start of inoculation and microthalli formed were measured from day 22. Results showed that the highest settlement occurred at 35 µmol m^-2s^-1 and 22 ºC, with 209.33 ± 24.58 sporophytes per cm². The lowest densities were obtained in the treatments of 18 and 20 ºC at 35 µmol m^-2s^-1, with 74.7 ± 45.5 and 57.0 ± 37.6 sporophytes per cm², respectively. The highest specific growth rate (SGR) was achieved at 70 µmol m^-2s^-1 (18 ºC), with 8.3% d^-1, followed by 70 µmol m^-2s^-1 (22 ºC), 70 µmol m^-2s^-1 (20 ºC) with 8.2 and 8.1% d^-1, respectively. In conclusion, sporophytes of C. chamissoi can develop at a higher speed at an irradiance of 70 µmol m^-2 s^-1, considering that increasing the temperature can generate a decrease in the growth rate.