One generation, illustrated in the photomicrograph above, lives in hydroid colonies, consisting of polyps. The polyps reproduce asexually, by budding, and create new polyps until it has formed a treelike colony. The colonies are dimorphic, having two types of polyps. Gastrozooids, or hydranths, are the feeding polyps. They have a mouth surrounded by stinging tentacles, giving them a flowerlike appearance, and are responsible for capturing and consuming food.
Food is digested in the gastrovascular cavity and provided to the rest of the colony.
The second generation of the life cycle begins when the medusae are released by the gonozooids and become free swimming forms. The planulae remain in a free-swimming form for a period of time, eventually attaching to a surface and developing into polyps. Specimens were illuminated through Nikon dichromatic filter blocks containing interference filters and a dichroic mirror and imaged with standard epi-fluorescence techniques. The filter combination utilized for the obelia stained specimen was a triple cube specific for DAPI, FITC, and Texas Red. All Rights Reserved .