Description: This small, stalked jellyfish has a body shaped like a funnel or bell up to 35 mm in diameter which is attached with a stalk that ends in an adhesive disc. It is usually pale pink to red in colour but can also be a pale olive green. It typically has 8 equally sized arms, ending in knobbed tentacles (secondary tentacles). The arms, bell and stalk are usually all similar in colour and the outer surface of the bell is granular in texture. This species does not have primary tentacles/anchors between the arms. There are nematocysts (stinging cells) visible as white spots on the bell between and around the arms.

Habitat: Typically found attached to seaweed or the seagrass Zostera marina; less commonly on rocks. Found from lower shore to around 10 m depth.

Distribution: There are scattered records around the coasts of Britain and Ireland. Few records from east coast of Scotland/England. Possibly under-recorded due to seasonality and small size.

Similar Species: There are several species of stalked jellyfish found in Britain and Ireland, but careful examination of key features often allows for in situ identification. If in doubt several good quality photographs showing the bell, stalk, arms and tentacles should be sufficient for ID. This species doesn’t possess primary tentacles/anchors but does possess nematocysts which are clearly visible inside the bell.

Key Identification Features:

• Although colouration between individuals is variable, all parts of an individual are uniform.
• Primary tentacles are absent.
• Outer surface of bell is granular in texture.
• Nematocysts visible as white spots inside bell.

Distribution Map from NBN: Calvadosia campanulata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Calvadosia campanulata at iNaturalist World Species Observations database.

GBIF data for Calvadosia campanulata

WoRMS: Calvadosia campanulata at World Register of Marine Species. Accepted name: Calvadosia campanulata (Lamouroux, 1815). AphiaID: 886183.

Classification: Biota; Animalia; Cnidaria; Medusozoa; Staurozoa; Stauromedusae; Amyostaurida; Kishinouyeidae; Calvadosia