A Method of Raising Clones of the Hydroid Phialidium gregarium (A. Agassiz, 1862) in the Laboratory

The hydroid Phialidium gregarium can be successfully culturedto sexual maturity at any time of the year and maintained foryears in a closed system marine aquarium. Artificial sea waterwas used in place of natural sea water and was renewed by one-quarterof its volume each 4 weeks, Freshly hatched Artemia naupliiwere used as the sole food source. Methods for obtaining coloniesof a single genotype from planulae are described. Subculturingpieces from parental stock is accomplished by a new method.A new technique for removing hydroid colonies from their substratefor histological study is described.