The common Japanese conger Conger myriaster is an important commercial coastal fisheries species in East Asia, but its spawning area has not been determined. A larval sampling survey was conducted in September 2008 along 136°E between 13°N and 22°N, which roughly followed the Kyushu-Palau Ridge in the western North Pacific. Twenty larval specimens were confirmed to be C. myriaster using DNA analysis. Two were newly hatched larvae (preleptocephali) 5. 8 and 7. 8 mm in total length (TL), which were caught at 17°N. The 5. 8 mm TL larva was estimated to be 3-4 days after hatching, the youngest preleptocephalus (i. e., the earliest stage) of this species ever collected. Eighteen other leptocephali were caught at 18°N and 21°N, and these ranged from 18. 6 to 40. 0 mm TL. Based on these collections, we discerned that there is a spawning area of C. myriaster in the area along the Kyushu-Palau Ridge approximately 380 km south of Okinotorishima Island. Similar to the Japanese eel spawning area along the West Mariana Ridge, the Kyushu-Palau Ridge may play an important role as a landmark of the spawning area. The discovery of this offshore spawning area should lead us to a better understanding of the recruitment mechanisms of C. myriaster, and help to facilitate future international management efforts.
All Science Journal Classification (ASJC) codes
- Aquatic Science