Practice question

Ecological profile of lophophorate phyla reflects adaptation to stable suspension feeding from stationary posture with minimal energy. Overwhelming majority marine benthic, either epibenthic attached to rocks, shells or seaweeds, or infaunal burrowers. Solitary phoronids construct chitinous tubes in sand, brachiopods permanently attached by muscular pedicle, bryozoans form diverse encrusting sheets or erect colonies. Sessility favors filter feeding via lophophore generating self current, low metabolism, chemical defense. Few freshwater representatives exist among phylactolaemate bryozoans. Planktonic stages like actinotrocha and cyphonautes ensure dispersal. Predominantly marine sessile existence distinguishes them from active annelids and mobile molluscs.