#1374 - Acetabularia sp. - Mermaid’s Wineglass
Most likely Acetabularia caliculus. AKA Umbrella Alga
Spotted by Frances Hammond while they were snorkeling at Woodman Point. I was excessively excited to see the photo, since I didn’t know Acetabularia even grew around here. It’s most common in tropical seas, but extends into warm temperate areas as well, which explains why we have it this far south.
It might not look like much, since each stem is only 3 or 4 cm long, but the fascinating thing about it is that each thallus is a single cell, with the nucleus down in the rhizoid. That makes it a wonderful test subject for studies of cell biology, and from the 1930s–1950s Joachim Hämmerling’s experiments proved that Acetabularia's genetic information is contained in the nucleus. This was the first demonstration that genes are encoded by DNA in eukaryotes.