Aggregating Cup Coral

Astrangia haimei

The Aggregating Cup Coral, Astrangia haimei, is a stony coral species identifiable by its small, cylindrical polyps. Each corallite measures about 2.5–3 mm in diameter and can extend more than 6.35 mm above the basal structure. The polyps are usually orange, though darker brown shades are also observed. The translucent tentacles end in a white, spherical tip, and when retracted, the coral's cup shape and simple septa are more visible. This coral species inhabits the Eastern Pacific Ocean, predominantly along the coast from Monterey Bay, California, to the Gulf of California and Baja California. It is found from sea level down to 53 meters, often on vertical rock faces with moderate to high water flow. Although primarily subtidal, it can also be seen in the low intertidal zone. Astrangia haimei feeds on plankton, which it captures using its stinging tentacles. Reproduction occurs through stolons, and like other Anthozoa members, it may be gonochoric or hermaphroditic. The zygote develops into a planktonic planula larva before settling. The conservation status of this species is not evaluated, and it is relatively uncommon in its range.