Exploitation ofCornucopina tuba(Bryozoa: Cheilostomata) byAetea curta(Bryozoa: Cheilostomata)

Distal portions of zooids of uniserial, encrusting Aetea colonies curve abruptly away from the encrusted substratum. This characteristic, plus highly directional growth capability, enabled A. curta infesting an erect Cornucopina tuba colony to position its feeding structures consistently above the host colony, perhaps as a rheophilic growth response of individual zooids to feeding currents set up by the host.