First report of field sampling and identification of crown-of-thorns starfish larvae

摘要

To date, neld sampling ana identification of the larvae of the coral-eating starfish Acanthaster planci have not been successfully performed (Birkeland 1990). We collected water samples (500 L) from 5 different depths (surface, 3 m, 7 m, 11m, 15 m, and near the bottom) to find A. planci larvae on June 29, 2005, during the spawning period (Yasuda et al. 2010). The samples were obtained from Yabiji Reef, off Miyako Island, Okinawa, Japan (25ori3.85’TSf, 125。14'49.20〃E， Fig. 1A), where a population outbreak of A. planci was observed (Fig. IB). We used a stereoscopic microscope to find and isolate 26 possible starfish larvae (gastrula and bipinnaria stages; Fig. 1C and D, respectively) from the samples, which were preserved in ethanol (>70%). We extracted DNA using the DNeasy blood & tissue kit (Qiagen), and directly sequenced partial mitochondrial DNA fragments amplified by using a previously published COI primer pair (Vogler et al. 2008) and a putative control region primer pair (Timmers et al. 2011). The latter primer pair can discriminate A.