Aspidelectra melolontha

General description: 

Aspidelectra melolontha is an encrusting bryozoan, characteristic of low salinity or brackish water communities. It only known to occur with certainty from the estuaries of south-east England (Rivers Crouch, Roach and Thames) and from a few similar localities on the Danish, Belgian and German coasts. It has also been recorded from a limited number of shallow stations in the Dover Strait in association with Conopeum reticulum and Electra monostachys

Colonies form encrusting, lobed, fan-like or dendritically branched patches on the inner surface of shells, often in great abundance on Ostrea and Mytilus valves. The small autozooids of this species are arranged in a regular linear series, which branch frequently giving rise to the lobed appearance of the colon.