Camera (cephalopod)

Cutaway of a nautilus shell showing the chambers

Camerae (singular camera) are the spaces or chambers enclosed between two adjacent septa in the phragmocone of a nautiloid or ammonoid cephalopod. These can be seen in cross-sections of a nautilus shell and in the polished cross-sections of ammonites. In life these chambers are filled with gas, mediated by the siphuncle, and used to control buoyancy.

Some Palaeozoic nautiloid genera, especially those with long, straight shells, are distinguished by cameral deposits. These were accumulations of calcium carbonate secreted in the empty chambers of the shell, used for ballast and control of buoyancy. The nature and form of these deposits are very useful in nautiloid classification.

References

• Flower, R. H. (1955). "Cameral deposits in orthoconic nautiloids". Geological Magazine. 92 (2): 89–103. doi:10.1017/S0016756800063408. 

Cephalopod anatomy
Shell	Shell types External shells: Ammonoid shell Argonautid eggcase Nautiloid shell Orthocone Internal shells: Belemnoid guard Cirrate shell Cuttlebone Gladius (pen) Spirula shell Stylet External features Aperture Apex Callus Lirae Periostracum Sculpture Spire Sutures Umbilicus Internal features Body chamber Camerae Nacre Phragmocone Septa Siphuncle Whorls
Mantle	External anatomy Funnel Dermal structures Fins (wings) Mantle locking-apparatus Internal anatomy Branchial hearts Ctenidia (gills) Hepatopancreas (digestive gland) Ink sac and ink Needham's sac Nephridia ("kidneys") Nidamental glands Osphradium Pericardial glands
Head and limbs	Brachial crown Arms Hectocotylus Tentacles Buccal region Aptychus Beak Odontophore Radula Spadix and antispadix Other parts Eyes Statocysts
General	Chromatophores Photophores Nervous system Squid giant axon Squid giant synapse
Developmental stages: Spawn → Paralarva (Doratopsis stage) → Juvenile → Subadult → Adult • Egg fossils • Protoconch (embryonic shell)