Tentacles soon sprout out from one end of the embryo's body and a mouth is formed; the column becomes more slender and attaches itself by the aboral pole to some solid object.
"Freshwater Sponges, Hydroids & Polyzoa"
Nelson Annandale
Young individuals are often, and adults occasionally, found floating free in the water, either with the mouth uppermost and the tentacles extended so as to cover as large an area as possible or with the aboral pole at the surface.
"Freshwater Sponges, Hydroids & Polyzoa"
Nelson Annandale