Hydroid sampled in the marina of Zeebruge only once in the period 1999-2003: 1 ex on September 4th 2003. Medusa sometimes very common: May and June 2001, May and September 2003. Only one male was found on 60 medusa. Between 7° and 15°C the hydroid produces small eggs that develop to small hydroids on the gonads. Between 15° and 20°C, the hydroid produces larger resting-eggs. In captivity they sank and attached to the bottom of the recipient. Two months later few hydroids were born at 22°C and three weeks later one of them produced young medusa between the tentacles.
