Ecological studies of economic red algae. II. Culture studies of Chondrus crispus Stackhouse and Gigartina stellata (Stackhouse) batters

The carpospores of Chondrus crispus Stackhouse and Gigartina stellata (Stackhouse) Batters were grown under a variety of light intensities, temperatures, and salinities. Chondrus exhibited a rapid increase in growth concurrent with increasing intensities up to 440 ft-c and tended to level off above this intensity. Gigartina exhibited a less rapid, but more consistent, increase in cell production coincident with increasing light intensity through 770 ft-c. The growth of both species was accelerated with increasing temperatures to 19 °C. Spores of C. crispus germinated and grew relatively rapidly over a broad range of salinities (15–45‰ at 19°C). Gigartina exhibited a more restricted tolerance to reduced salinity (20 ‰ at 19°C). The local distribution and abundance of both species are correlated with their responses in culture as well as with previous observations on their photosynthesis and respiration.