Tubulariidae Fleming, 1828

The family Tubulariidae belongs to the suborder Aplanulata. This suborder encompasses species of the order Anthoathecata with a life cycle characterized by both the absence of a ciliated planula larva, and a direct development from fertilized eggs into young polyps. The systematics of the group has recently been revised based on new information available from molecular phylogenetic studies. Members of the family Tubulariidae usually live in shallow marine or brackish waters, where polyps are attached to different types of substrata. In some species of Tubulariidae,  the planktonic medusa phase does not fully develop and remains attached to the polyp as fixed sporosacs.

This leaflet briefly introduces  the family Tubulariidae, describing the taxonomic and ecological characteristics of fourEctopleura species and oneHybocodon species for which free-living planktonic medusa stages have been reported in the North Atlantic Ocean and/or in the Mediterranean Sea (E. dumortierii, E. minerva, E. sacculifera, E. wrighti,and H. prolifer). A taxonomic key to distinguish the two genera is also included. 

This leaflet is an update of the ICES Identification Leaflets for Plankton No. 2, published by Russell (1939). The revisions of the original leaflet are mainly based on the recent revision of athecate hydroids published by Schuchert (2012), the book of Bouillon et al.  (2006),  and the information provided by the World Register of Marine Species (WoRMS, 2020).