Nautilus shell
Smile on Saturday
Backlit close up!
Nautiluses are found in only the Indo-Pacific, from 30° N to 30° S latitude and 90° E to 175° E longitude. They inhabit the deep slopes of coral reefs.
Nautiluses reproduce by laying eggs. Gravid females attach the fertilized eggs to rocks in shallow waters, whereupon the eggs take eight to twelve months to develop until the 30 millimetres juveniles hatch.
Nautiluses are the sole living cephalopods whose bony body structure is externalized as a planispiral shell. The animal can withdraw completely into its shell and close the opening with a leathery hood formed from two specially folded tentacles. The shell is coiled, aragonitic, nacreous and pressure resistant, imploding at a depth of about 800 m (2,600 ft). The nautilus shell is composed of two layers: a matte white outer layer, and a striking white iridescent inner layer. The innermost portion of the shell is a pearlescent blue-gray. The osmeña pearl, contrarily to its name, is not a pearl, but a jewellery product derived from this part of the shell.
Size
Nautilus pompilius is the largest species in the genus. One form from Indonesia and northern Australia, once called Nautilus repertus, may reach 25.4 cm (10.0 in) in diameter.[13] However, most nautilus species never exceed 20 cm
Nautilus shell
Smile on Saturday
Backlit close up!
Nautiluses are found in only the Indo-Pacific, from 30° N to 30° S latitude and 90° E to 175° E longitude. They inhabit the deep slopes of coral reefs.
Nautiluses reproduce by laying eggs. Gravid females attach the fertilized eggs to rocks in shallow waters, whereupon the eggs take eight to twelve months to develop until the 30 millimetres juveniles hatch.
Nautiluses are the sole living cephalopods whose bony body structure is externalized as a planispiral shell. The animal can withdraw completely into its shell and close the opening with a leathery hood formed from two specially folded tentacles. The shell is coiled, aragonitic, nacreous and pressure resistant, imploding at a depth of about 800 m (2,600 ft). The nautilus shell is composed of two layers: a matte white outer layer, and a striking white iridescent inner layer. The innermost portion of the shell is a pearlescent blue-gray. The osmeña pearl, contrarily to its name, is not a pearl, but a jewellery product derived from this part of the shell.
Size
Nautilus pompilius is the largest species in the genus. One form from Indonesia and northern Australia, once called Nautilus repertus, may reach 25.4 cm (10.0 in) in diameter.[13] However, most nautilus species never exceed 20 cm