2005年から2015年にかけての無人潜水機(ROV)を使ったインドネシアシーラカンスLatimeria menadoensisの調査

抄録

Habitats of the Indonesian coelacanth, Latimeria menadoensis, were investigated by Remotely Operated Vehicles (ROVs) surveys in the northern coast of Sulawesi Island and southern coast of Biak Island by collaboration of Aquamarine Fukushima (Japan), and Indonesian Institute of Sciences and Sam Ratulangi University (Indonesia) from 2005 to 2015. The Remotely Operated Vehicles operations were conducted 1173 times and coelacanths were encountered 30 times. A total of 30 different individuals were observed at a depth range from 115.6 m to 218.9 m deep. The water temperature was between 12.4 to 21.5 ºC. Most of the individuals were found alone, however, schools of two, three and six individuals were also observed. The Indonesian coelacanth, L. menadoensis, was observed at a similar depth of the African coelacanth, Latimeria chalumnae, and the temperature range also seems to be very similar. However, Latimeria menadoensis was sometimes observed besides big rocks or the steep wall. It seems to be less sensitive to daylight than L. chalumnae. Here we report also, for the first time in the world, a juvenile coelacanth was observed in a small crack at 165 to 171 m depth during these surveys.