Spawning event of Pherecardia striata followed by washed up individuals in Hawaii

Abstract

Pherecardia striata (Kinberg 1857) is a polychaete worm of the family Amphinomidae. Amphinomids are known as ‘fireworms’ due to the discomfort and itching sensation if touched. P. striata is an active predator that can swallow pieces of fish and live prey such as small crabs, shelled gastropods, and other worms and even be hand fed in aquaria (Glasby and Bailey-Brock 2001). This is a large species reaching up to 20 cm in length in Hawaii and distributed throughout the IndoPacific (Bailey-Brock 1987). In Hawaiian shallow coral reefs, this species is known to spawn on a summer night, an event most likely triggered by a full moon. The spawning event was photographed on the night of July 25, 2005 in Coconut Island, Kaneohe Bay (Darlyne Murawski pers. comm.) and featured in Holland (2007) in a special issue of National Geographic. On the morning of August 17, 2014, dozens of individuals of Pherecardia striata were found dead at Kahanamoku Beach, 21.281602, -157.838943 (Fig. 1). Nearly ten years before, on August 6, 2004, about 200 individuals were found in a nearby beach (Ala Moana Beach , 21.288693, -157.847722) as reported in a local newspaper (Fujimori 2004). Although spawning events for this species are known to occur annually, heavy rains may have caused the massive deaths of individuals reported in 2004 and 2014. Predictions on spawning events of marine worms are very exact for the palolo worm (Palola viridis Gray in Stair, 1847) that spawns at the third quarter of the moon in October or November. This event is highly celebrated as the worms are eaten raw in the South Pacific. The three spawning events recorded for Pherecardia striata are documented herein for the third quarter of the moon of July or August and can be further investigated and celebrated by night divers and tourists.