Ecology

These particular colonies of Myrionema hargitti were collected, possibly unknowingly, from the reef flats off Heron Island. They quickly flourished in the reef aquarium, and have demonstrated equally successful invasion and colonial settlement in tropical marine tanks around the world (Joy 2011). These organisms commonly colonise on rocks and coral flats, as demonstrated in the below figure.




Figure 3. Myrionema hargitti commonly colonise rocks and coral flats.



Research illustrates the reliance of this genus on habitats with a reasonable amount of light, explained by the dependence of their zooxanthellae symbionts on photosynthesis (see Anatomy and Physiology). They thrive in areas of high circulation, a requirement for capturing prey with their tentacles. For this reason, they are often located near water pumps in tanks and in tropical shallows. This genus rarely exceeds depths of 2m, in order to optimise photosynthetic efficiency and maximise water circulation.

Based on this fact, aquarium owners suffering from a Myrionema invasion have demonstrated successful control—albeit somewhat limited—in shrouding their tanks in darkness for a number of days (Ronchi 2012).