Fascinating cuttlefish
by Paula Weston
With green blood, three hearts, and able to change colour in a flash, it sounds
like a ‘weird aliens’ movie creature. Actually, the cuttlefish is a
seafood delicacy.
The eye of the cuttlefish, like that of the squid, has a very similar design to
our own—but evolutionists must believe both eye types evolved separately,
so the similarity is just a ‘coincidence’.
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The world’s oceans are filled with amazingly complex creatures, perhaps none
more so than the cuttlefish. This fascinating mollusk is probably best known for
its cuttlebone, usually found at the bottom of budgie cages. However, the cuttlefish
is much more than just a calcium supplement for caged birds.
In addition to being able to camouflage itself in a range of environments, the cuttlefish
is able to change colour spectacularly when excited, flashing rapidly from yellow
to red-orange and blue-green.
It also has a complex propulsion and buoyancy system (the latter similar to that
used in submarines), and a sharp ‘beak’ which allows it to cut open
flesh like a pair of scissors, so it can use its tentacles to tear out meat.
Socially, the giant Australian cuttlefish is a favorite with divers during breeding
season, when the usually shy marine creature becomes outgoing, following divers
through the water and often holding still for a scratch or pat.1
The cuttlefish belongs to the mollusk class Cephalopoda—which means ‘head-footed’
derived from the Greek words kephale (head) and podes (feet)—ranging
from 2.4 centimetres (around one inch) to 90 centimetres (three feet) in length
(even bigger in the case of the giant Australian cuttlefish, which can reach the
length of a small man).
Cuttlefish evolution? Think again
Classification2:
Phylum: Mollusca
Class: Cephalopoda
Subclass: Dibrachiata
Order: Sepioida
Family: Sepiidae
Genus: Sepia
Like every animal phylum (a major division of life), the mollusks appear with no
ancestors in the so-called Cambrian rocks. (A hypothetical archimollusc is set forth
as the ancestor of all mollusks, but is not found in the fossil record.)3
The class Cephalopods appear in the fossil record in Ordovician rocks, again without
evolutionary transition.
Encyclopedia Britannica says of the cephalopods, ‘Phylogenetic [evolutionary]
linkages are still highly theoretical …’.4 The order sepioids
appears in rocks no lower than the Jurassic system, again with no transitions leading
to them. It is possible that all fossil and living sepioids may be the descendants
of one ancestral created kind, based on the structural variation described in fossils.5
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Cuttlefish blood looks blue-green because it uses the pigment hemocyanin to carry
oxygen, unlike our blood which uses the red pigment hemoglobin. The cuttlefish has
three hearts—one for each set of gills, and one for the rest of the body.
It has eight sucker-lined arms and two prehensile tentacles (which can be withdrawn
into pouches under the eyes), and mainly feeds on fish, crustaceans and other mollusks.
It hunts in the daylight, catching nocturnal prawns by blowing with its funnel and
jetting them out of the sand. Like an octopus, the cuttlefish produces ‘ink’,
in this case a brown fluid called sepia. However, it uses this defence only as a
last resort, preferring to rely on its extensive camouflage capabilities both to
hunt prey and avoid its own predators, such as sharks and dolphins.
The cuttlefish has a skin comprising three layers of chromatophores (colour pigment
cells)—a bright yellow layer near the surface, under which is an orange-red
layer and finally a dark base. Transformation from one colour to another, which
can take less than a second, is controlled by the nervous system. In just a few
seconds, it can run a whole gamut of colours.
The cuttlefish propels itself using a series of spurts, drawing water into a compression
chamber which it squeezes to jet the water out a funnel under the head. Direction
changes can be made by swivelling the nozzle of this funnel, and narrowing the funnel
controls speed.
Like a submarine, the cuttlefish fills tiny compartments in its cuttlebone with
gas to help maintain neutral buoyancy. This helps the cephalopod
hover above the ocean floor, because although it has a sophisticated propulsion
system its large cuttlebone does not allow it to be overly active, or quick in the
water. It is hard to imagine how this slow-paced species could have survived over
millions of years of evolution before it developed its all-important camouflage
capabilities, yet evolutionists believe this, even though there is no evidence to
show how such features developed.
The cuttlefish also has eyes which are similar in construction to human eyes, but
evolutionists do not believe it has any direct evolutionary relationship to humans
(i.e. there is no possible ancestor to both cuttlefish and humans which could have
had such an eye). So this similarity is explained away as ‘convergent evolution’:
the eyes of the cuttlefish and other cephalopods ‘evolved independently’
to humans. In other words, it is simply an evolutionary coincidence.
However, the similarity in the design of both the cuttlefish and human eye is easily
explained—they had the same Designer! The origins of the amazing features
of the cuttlefish can be more easily explained if we accept it as just another miraculous
example of the work of the Creator.
Staying neutral
Redrawn after Clarkson, E., Invertebrate Palaeontology and Evolution, George Allen
and Unwin, London, 1979 (Seventh impression 1984), p.167.
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The cuttlefish is a bottom-dweller which often lies in ambush
for smaller animals. For this way of life, it needs to keep itself at neutral buoyancy,
so that it neither sinks nor rises. At first glance, it would seem sufficient for
the Creator to have endowed it with a fixed overall density, so that its own weight
was exactly balanced by the upthrust of the surrounding water.
However, if the depth changes, so will the amount of ‘lift’
from the water. Therefore in order to be able to operate at varying depths and water
densities, cuttlefish need to be able to adjust their overall density so as to always
remain ‘neutral’ in the water. The cuttlefish does this by an ingenious
mechanism. The bony shell actually has many narrow chambers. If these were all filled
with gas, they would give a lift of up to 4% of the animal’s weight. However,
they are only part-filled with gas—the darker areas shown are where it is
part-filled with liquid. The cuttlefish is able to pump liquid in and out of that
section as needed to keep the buoyancy ‘just right’.
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Further reading
Other resources:
- ‘The Giant Australian Cuttlefish’, Geo 9(1),
March–May 1987, pp. 58–71.
- Encyclopedia Britannica, (fifteenth edition), 3:814, 1992.
References
- ‘Dolphins frolic as a seasonal tragedy unfolds beneath’, Sydney
Morning Herald, September 14, 1996.
- R. Moore, C. Lalicker, and A. Fischer, Invertebrate Fossils, McGraw Hill,
New York, 1952.
- Clarkson, Invertebrate Paleontology and Evolution, George Allen & Unwin,
London (7th impression), 1984.
- Encyclopædia Britannica, (fifteenth edition), 24:322,
1992.
- Ref. 1., chapter 8, ‘mollusks’.
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