Chambered nautilus
Videos
The chambered nautilus, also called the pearly nautilus, is the best-known species of nautilus. The shell, when cut away, reveals a lining of lustrous nacre and displays a nearly perfect equiangular spiral, although it is not a golden spiral. The shell exhibits countershading, being light on the bottom and dark on top. This is to help avoid predators, because when seen from above, it blends in with the darkness of the sea, and when seen from below, it blends in with the light coming from above.
The first and so far oldest known fossil of chambered nautilus, displayed at the Philippine National Museum.
1896 skiagraph (X-ray photograph) of a N. pompilius by James Green & James H. Gardiner, from Proceedings of the Malacological Society of London, Vol. II, Pl. XV, p. 178
16th-century Northern Mannerist nautilus cup
Waikīkī Aquarium
Videos
The Waikīkī Aquarium is an aquarium in Honolulu, Hawaii, United States. It was founded in 1904 and has been an institution of the University of Hawaiʻi at Mānoa since 1919. The aquarium is the second-oldest still-operating public aquarium in the United States, after the New York Aquarium.
Waikiki Aquarium entrance
Coral reef exhibit at Waikiki Aquarium