Biology

Inhabits rocky crevices (Ref. 11482). Two paratypes that were collected at low tide between blocks of lava in about 50 cm of water, were observed to move slowly close to the sand bottom. Experiments that were carried out showed that O. deroyi can tolerate a widevariation in salinity, but not the low salinity in which O. galapagosensis lives. Consequently, there is an ecological barrier separating the two species. Only about five embryos were observed in ripe females (Ref. 57883).