Environmental constraints on the photosynthetic rate of the marine flatworm Symsagittifera roscoffensis

Symsagittifera roscoffensis, an Acoel flatworm that lives within the intertidal zone, was first discovered over a century ago as “plant animal” due to its symbiotic relationship with alga Tetraselmis convolutae. Although commonly used model organism in biomedical research, there is little information regarding life history or how environmental factors affect this organism. In study, we investigated effects of range abiotic on S. roscoffensis by measuring photosynthetic oxygen production rate under different salinities, temperatures, light intensities, photoperiods, and nutrient concentrations 6 days. Salinity (20, 30 40) had effect rate, whereas temperature 14 °C yielded significantly higher final than 0 °C. The lowest intensity (21 μmol m−2 s−1), shortest photoperiod (8 L:16 D) intermediate concentration (f/4) resulted highest rates. Our results showed ability tolerate remain photosynthetically active wide conditions it likely experience zone. Using our experimental data, estimated able produce 174% body C d−1 via photosynthesis alone, which could explain total absence heterotrophic feeding appeared be robust easy cultivate, should open new opportunities for wider applications.