Camerae (singular camera) are the spaces or chambers enclosed between two adjacent
septa
SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...
in the
phragmocone of a
nautiloid or
ammonoid cephalopod molluscus. These can be seen in cross-sections of a
nautilus
A nautilus (; ) is any of the various species within the cephalopod family Nautilidae. This is the sole extant family of the superfamily Nautilaceae and the suborder Nautilina.
It comprises nine living species in two genera, the type genus, ty ...
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
Buoyancy (), or upthrust, is the force exerted by a fluid opposing the weight of a partially or fully immersed object (which may be also be a parcel of fluid). In a column of fluid, pressure increases with depth as a result of the weight of t ...
.
Some
Palaeozoic nautiloid genera, especially those with
long, straight shells, are distinguished by cameral deposits. These were accumulations of
calcium carbonate
Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ...
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
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{{DEFAULTSORT:Camera (Anatomy)
Cephalopod zootomy