Nautiluses have been around for a long time - like, before the dinosaurs kind of long.
They appeared nearly 500 million years ago, and over the course of their history there have been
thousands of species. Today, there are less than ten species belonging to the Nautilidae
family which is sectioned off into two genera: Nautilus and Allonautilus. Species from the
Nautilus genus are the kinds with which you are likely most familiar because species from
the Allonautilus genus, who are referred to as fuzzy nautiluses, are rare and have only been
observed living in the wild fewer than five times. That’s as rare as Chester saying no to food! Oh,
and there are animals called paper nautiluses, but they aren’t true nautiluses - they’re octopuses!
The name nautilus is appropriate for these seafaring cephalopods because ‘nautilus’ is
derived from the latin word meaning ‘sailor’. The way these sailors move about is via jet propulsion
thanks to their unique design. Nautilus shells form with chambers - if you were to cut one in
half, which we don’t recommend since that would hurt the little gal inside, you would see 30 or
more compartments. When a nautilus is born, it has few compartments. The squishy body part of the
nautilus is found in the outermost chamber while the remaining chambers are filled with a gas and
liquid mixture that provide the animal buoyancy. By changing the ratio of gas to liquid within this
mixture, nautiluses can make themselves sink or float. To move, a nautilus will pull water into
the upper part of its shell and then push it back out through a siphon which is pointed in
the direct opposite of where the animal wants to move. That all might sound complicated, but
they’ve been doing it for millions of years so I’d say it’s best we don’t question it at this point.
For as durable as nautiluses have been throughout history,
they don’t really hold up well in captivity, so we haven’t had as much opportunity to study them.
They’re captured for their beautiful, elaborate shells which are sold as decoration pieces,
but it’s believed that their numbers could be declining so many people frown upon this practice.
Nautiluses are gorgeous, though, boasting colorful shades of red or orange against
creamy whites. They can reach 10 inches (25.4cm) in shell diameter and they have upwards of 90 or
more tentacles that can be completely retracted into their shell and hidden under a tough hood.
Their tentacles do not have suction cups like those of an octopus and instead have groves that
help with holding and grabbing food. Nautiluses eat crustaceans as well as fish and they also
scavenge for dead animals. In turn they are consumed by sea turtles, sharks, octopuses,
and sometimes even other nautiluses. In order to avoid predators, nautiluses are mainly nocturnal,
and some species participate in a daily migration. When we landlocked mammals think of migration we
likely think of moving on a horizontal plane, but many sea creatures, nautiluses included,
migrate on a vertical plane. During the day, nautiluses will sink themselves to as far as
2,000 feet (610m) below the ocean’s surface and away from light and predators. They can’t dive
too deep, however, because after a little more than 2,600 feet (800m), their shells will no
longer be able to withstand water pressure and may collapse on themselves. At night,
they’ll rise up to 300 feet (91.4m) and take their time enjoying their nocturnal feast.
They have relatively bad eyesight and likely use smell to find their food, so light isn’t really a
food-finding factor for these sailors. They hunt and live in the South Pacific and Indian Oceans.
Nautiluses are born from large eggs that are about 1.5 inches (3.81cm) long.
The eggs are laid by females who attach them to surfaces. The eggs take about a year to develop
before the baby nautilus hatches. Nautiluses take years, sometimes as many as ten or more,
to reach maturity and readiness to mate. This is pretty much opposite their other
cephalopod cousins who develop rather quick and typically only reproduce once in their lifetime.
And nautiluses break the record when it comes to their life expectancy. Where most cephalopods
only live about a year, nautiluses can live to be twenty and possibly older!
For more facts on nautiluses, be sure to read through the links in the description.
Tell us in the comments what you think of nautiluses.
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