The production of tubes by the serpulid polychaete Mercierella enigmatica is compared with somatic growth and reproduction, and is shown to account for the greatest portion of production energy expenditure.
The tube of a serpulid polychaete consists of two major fractions, a conspicuous calcareous component comprising small crystals of aragonite or calcite, and a more diffuse organic matrix (Hedley, 1956; Neff; 1971). The continuity of the organic matrix was demonstrated by Hedley (1956), who showed that careful decalcifkation failed to disturb the form of the tube of Pomatoceros triqueter (L.).
The serpulid Mercierella enigmatica Fauvel (Ficopomatus enigmaticus cf. ten Hove & Weerdenburg, 1978) secretes a hard, calcareous tube shortly after it settles from the plankton (Rullier, 1955; Vuillemin, 1965). Initially, tube growth is relatively fast, but as the tube increases in length so the rate of growth declines. However, the tube of the adult worm can be as much as 80 mm in length, or more than four times the length of its body.