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 Mexico (Fischer et al. 1989, 2000).

 

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 Wilson, 1986 from the Oligocene of Baja California (Mexico). Geobios 22, 761-775.

 

Dodecaceria caulleryi

 

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 South Africa.

 

Dodecaceria caulleryi

 

Dodecaceria caulleryi, longitudinal section, showing the lamellae in tube wall composed of aragonitic irregular spherulitic prisms. Recent, Atlantic coast of South Africa.

 

Dodecaceria caulleryi

 

Dodecaceria caulleryi, longitudinal section, detailed view of aragonitic irregular spherulitic prisms in the tube wall. Recent, Atlantic coast of South Africa.

 

Dodecaceria caulleryi

 

Dodecaceria caulleryi, longitudinal section, showing lamellar tube wall composed of aragonitic spherulitic prisms. Tube interior left on the SEM photograph. Recent, Atlantic coast of South Africa.

 

Diplochaetetes mexicanus

 

Diplochaetetes mexicanus, longitudinal section, showing somewhat irregular lamellae of the tube wall composed of irregular spherulitic prisms. Fossil, Oligocene, Mexico.

 

Diplochaetetes mexicanus

 

Diplochaetetes mexicanus, longitudinal section, showing details of irregular spherulitic prisms. Fossil, Oligocene, Mexico.

 

Diplochaetetes mexicanus

 

Diplochaetetes mexicanus, longitudinal section, showing spherulite in the tube wall. Fossil, Oligocene, Mexico.

 

Diplochaetetes mexicanus

 

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.