Photograph by Ria Tan
A Blue Button (Porpita pacifica) at Sisters Islands
Location, date and time: Singapore Straits, Big Sister Island (Pulau Subar Laut); 20 April 2014; 0845 hrs
Observation: An example with disc of about 1.5 cm diameter was found washed ashore on the beach at the mid-tide line with other flotsam. When placed into a bucket of seawater, all the blue appendages fell off the flat, white central disk. It was assumed that the animal was freshly dead.
Remarks: The Blue Button is a highly modified hydrozoan that inhabits the open seas and oceanic waters, drifting about at or near the surface. The occasional examples are stranded on reefs and beaches when brought inshore by winds or currents (Colin & Arneson, 1995: 72-73).
- Colin, P. L. & C. Arneson, 1995. Tropical Pacific Invertebrates. A Field Guide to the Marine Invertebrates Occurring on Tropical Pacific Coral Reefs, Seagrass Beds and Mangroves. Coral Reef Press, Beverly Hills, California, USA. vii + 296 pp.