HABITAT AND POPULATION-SIZE OF THE COELACANTH LATIMERIA-CHALUMNAE AT GRAND COMORO

In 1987 and 1989 coelacanths were observed for the first time in their natural habitat with the help of submersibles. Coelacanths were found between 150-253 m depth, their preferential depth seems to be around 200 m; the water temperature ranged between 16.5-22.8-degrees-C. During the day coelacanths aggregate in small non-aggressive groups in sheltered lava-caves. Caves might be a limiting factor for distribution. At night they leave the caves for hunting by drifting singly along the steep lava slopes. They migrate between different caves located within a large home range covering more than 8 km coastline. Coelacanths are site-attached, some for a period of at least 2 years. Our own observations and earlier catch records show that only the west coast of Grand Comoro is a suitable coelacanth habitat with more structural complexity and prey fish abundance than other coastlines of the island. From our survey we estimated a total coelacanth population off Grand Comoro to be 150-210 individuals; a saturated population would be 370-510 individuals. This small relict population seems to be stable. International protection of coelacanths against commercial interests is needed.