FUNCTIONAL-ANATOMY OF NAUSITORA-FUSTICULA (JEFFREYS, 1860) (BIVALVIA,TEREDINIDAE)

A study of the functional anatomy of Nausitora fusticula (Jeffreys, 18 60) correlated with the habitat of the species was made. Special atten tion was paid to the siphons, pallets, and musculature associated with them, ctenidia, labial palps, foot, and mantle. The analysis of the s iphons revealed the presence of cilia, not described for any Teredinid ne previously studied. Each ctenidium of N. fusticula is formed only b y the external demibranch, with the blades in a ''V'' form. The ctenid ia, associated with the rejection tracts of the mantle, present a good mechanism to deal with large quantities of particles, possibly an ada ptation for life in turbid waters. The labial palps are extremely redu ced. Analysis of the foot ciliary currents revealed that the foot part icipates in the removal of wood fragments produced by the action of th e shell against the gallery wall, and that only part of these fragment s are ingested, the remainder being eliminated as pseudofeces. The fun ctional anatomy of N. fusticula suggests that for this species plankto n probably is a more important food item than wood.