Studies on the fauna of Curacao and other Caribbean Islands: No. 213. Observations on the light-inhibited activity cycle and feeding behavior of the hydromedusa Olindias tenuis

Olindias tenuis is a shallow-water hydromedusa from the Caribbean that during the day is cryptic, residing among seagrass and algae and after sunset swims into the water column. The medusae forage by swimming towards the surface, and then slowly drifting downwards with the exumbrella uppermost and the long primary tentacles hanging below. Positive buoyancy of the umbrella reduces the sinking rate. Both the activity cycle and buoyancy appear to be regulated by light since the intensity of light alters the normal activity cycle both day and night. Feeding occurs once the medusae have entered the... Mehr ...