[DOC] [TLE] Nautilus - Wikipedia [PAR] The nautilus is a pelagic marine mollusc of the cephalopod family Nautilidae, the 
sole extant ... Like all cephalopods, the blood of the nautilus contains 
hemocyanin, which is ... The animal can withdraw completely into its shell and 
close the opening with ... The "ear" of the nautilus consists of structures called 
otocysts located... [DOC] [TLE] Cephalopod - Wikipedia [PAR] A cephalopod is any member of the molluscan class Cephalopoda These 
exclusively marine ... In the Coleoidea, the molluscan shell has been internalized 
or is absent, whereas in ... Left: An octopus opening a container with a screw cap 
.... Like most molluscs, cephalopods use hemocyanin, a copper-containing 
protein,... [DOC] [TLE] Chambered Nautilus - Deep Sea Creatures on Sea and Sky [PAR] Like the coelacanth, it has remained unchanged for over 400 million years. ... The 
nautilus is a mollusk and a member of the cephalopod family. ... A small tube 
near the animal's tentacles, known as a siphon, expels water under ... Each new 
chamber will be a little larger that the last, allowing the opening of the shell to... [DOC] [TLE] Cephalopods - Amazing Facts on Molluscs [PAR] Like that of other molluscs, cephalopods' bodies are divided in head, visceral sac 
... Among some squids (Loligo) all that is left of the shell is a flexible rod, called a 
... over the pinhole camera eye of a nautilus towards the lens eye of an octopus. 
... with water and presses the water out of the cavity's opening with high speed. [DOC] [TLE] Terminology and Morphology [PAR] Hinge line   Straight posterior margin of shell parallel with hinge axis; ... Pedicle 
opening   Variably shaped aperture in shell through which pedicle emerges. ..... 
Axil-arm   Arm including its branches borne by any branch of main-axil as seen 
in .... Modioliform  Shaped like shell of Modiolus; differing from mytiliform in that
... [DOC] [TLE] The Cephalopoda - University of California Museum of Paleontology [PAR] These "brainy" invertebrates have evolved suckered tentacles, camera-like ... 
Sutures are contact lines between shell chamber walls (called septa) and the ... 
were planispiral, the shells of some species were wide, open-coiled, kinked, 
twisted, or hooked. ... Three main clades are typically identified within the 
Cephalopoda... [DOC] [TLE] Watch: Octopus Carries CoconutBut Is It Using a Tool? [PAR] Jun 5, 2015 ... Main Menu .... When hunting for tasty morsels like crabs and scallops, octopuses 
must ... so letting go of the camera just wasn't an option," says Julian Finn, the ... 
jets to clear dens of sand and grit and stack rocks in front of the openings. ... 
Unlike mollusks such as clams, octopuses don't have a hard shell to... [DOC] [TLE] Biological Diversity 8 - Estrella Mountain Community College [PAR] Secretion of a mineral shell that allowed the animal to use the shell as a mineral 
repository. .... A rapid closing and opening of their two valves releases water in 
spurts. ... Bivalves, like other mollusks, have an open circulatory system. ... 
Squids possess a vestigial skeleton under the mantle, called the pen, which 
surrounds... [DOC] [TLE] Malacology Monthly: Inside-Out | Deep Sea News [PAR] Oct 16, 2015 ... Main menu ... of today's most popular marine mollusks ... First up, the aptly-
named Screw Turritella (Turritella terebra: Turritellidae) with a tall, twisting spire. 
... The opening  or aperture  of the shell is the front-door, and new ... to kill off 
their wild predators, like porcupine fishes, wrasse, bat rays, and crabs. [DOC] [TLE] Giant Squid | Smithsonian Ocean Portal [PAR] As the camera whirred, the research team pulled a 24-foot (7-meter) squid to the 
... A giant squid's body may look pretty simple: Like other squids and octopuses, it 
has two ... Squids belong to a particularly successful group of mollusks called the 
.... are completely airtight, contain valves and openings for refilling preservative... [DOC] [TLE] Learn About Ocean Animals - Home Science Tools [PAR] A person

Question: Like the opening in a camera, the main opening in the shell of a mollusk is called this
Answer: the aperture