Fluorescing Bowerbankia

This is a Bowerbankia species (attached to a scraggy thin, short-branched ecotype of Chondrus crispus) from Shoreham harbour. he image was taken using oblique LED lighting and it was not until I looked at the images that the blue 'fluorescent' (apparently) blobs showed up. They appear to be at the base of the zooid as they are not visible in the contracted state. Any suggestions as to which part of the animal this is?

Bowerbankia on Chondrus crispus
Bowerbankia on Chondrus crispus; Shoreham harbour, Sussex, Sept 2015