Fact Friday

Bubble Coral

The coral in the photograph looks more like a soft coral than a hard coral. Corals in the genus Plerogyra, termed bubble or grape corals, expand their water-filled bubbles or vesicles during the day in order to maximize the exposure of their symbiotic algae (zooxanthellae) to sunlight. At night, the vesicles retract so that their tentacles can expand to feed on small organisms. Watch this video to see the vesicles expanding: https://youtu.be/r5I6TM3nnbU

Photo Credit: Annelise Hagan

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Fact Friday

October 6, 2023


Although tunicates may at first glance appear to be related to sponges or sea anemones, they’re actually in the same phylum as humans and other vertebrates – Chordata. In their larval form, tunicates look like tadpoles, with a notochord and nerve chord (which become the spine and spinal cord in vertebrates).

Photo Credit: Ken Marks