Rhacostoma is a genus of aequoreid hydrozoans. It is monotypic with a single species, Rhacostoma atlanticum. It has been reported from the Atlantic coastline of North America, Colombia, western and central Africa.[1] The polyp stage is unknown.[2]
The medusae reach up to 30–40 cm (12–16 in) in diameter with the bell height 3–4 times less than the width.[1] Specimens found in the northern waters tend to be transparent, while those found farther south are tinted pink.[3] The broad stomach gives rise to 80–100 non-branching radial canals.[1] Tentacles are slightly more numerous than radial canals and do possess elongated conical bulbs.[1]
Rhacostoma is a genus of aequoreid hydrozoans. It is monotypic with a single species, Rhacostoma atlanticum. It has been reported from the Atlantic coastline of North America, Colombia, western and central Africa. The polyp stage is unknown.
