Tube ultrastructure in calcifying cirratulid
polychaetes
Several cirratulid
polychaetes are secreting calcareous tubes. Their tubes have multilamellar structure and are composed of
aragonite/calcite by the observations of Fischer et al. (2000) or Sr rich aragonite
according to the EDX analyses on Dodecaceria caulleryi (E. Dunca & O.
Vinn, personal observations). Fossil cirratulids are
known from the Oligocene in
References
Fischer, R., Pernet, B., Reitner, J. 2000. Organomineralization of Cirratulid Annelid Tubes-Fossil and Recent Examples. Facies 42, 35-50.
Fischer, R., Galli
Oliver, C., Reitner, J. 1989. Skeletal structure,
growth, and paleoecology of the patch reef-building polychaetes
worm Diplochaetetes mexicanus
Dodecaceria caulleryi,
longitudinal section, showing lamellar tube wall with the multiple septa. The
lamellae of septa are not continues with those forming the tube wall. Recent, Atlantic coast of
Dodecaceria caulleryi,
longitudinal section, showing the lamellae in tube wall composed of aragonitic irregular spherulitic prisms. Recent,
Atlantic coast of
Dodecaceria caulleryi,
longitudinal section, detailed view of aragonitic
irregular spherulitic prisms in the tube wall. Recent,
Atlantic coast of
Dodecaceria caulleryi,
longitudinal section, showing lamellar tube wall composed of aragonitic spherulitic prisms. Tube interior left on the
SEM photograph. Recent, Atlantic coast of
Diplochaetetes
mexicanus, longitudinal section, showing somewhat
irregular lamellae of the tube wall composed of irregular spherulitic prisms. Fossil,
Diplochaetetes
mexicanus, longitudinal section, showing details of
irregular spherulitic prisms. Fossil,
Diplochaetetes
mexicanus, longitudinal section, showing spherulite
in the tube wall. Fossil,
Diplochaetetes mexicanus, longitudinal section, showing homogeneous calcareous granules and rods in the tube wall. Formation of this structure could be result of the activity of some symbiotic bacteria (see Fischer et al. 2000). Fossil, Oligocene, Mexico.