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Book Review:
Cephalopods: Octopuses and
Cuttlefishes for the Home Aquarium
By:
Colin Dunlop and Nancy King
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| by Neale Monks |
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The maintenance of cephalopods, particularly the smaller species of
octopuses, has steadily become more popular over the years.
Cephalopods are molluscs in terms of classification, but unlike
snails or clams they are dynamic, intelligent animals adapt to a
highly predatory lifestyle. Many species display an ability to
learn tricks and adapt to their environment simply without parallel
among the invertebrates. Aquarists who maintain octopuses often
comment on their highly individual personalities, and come to think
of them with a level of affection more like that given to cats and
dogs.
Unfortunately for the casual hobbyist though, cephalopods are
difficult animals to maintain. All require pristine water
conditions, and most are very fussy feeders that only accept live
foods. Octopuses are notorious escape artists as well, so their
habitat has to be designed not only to stop them from getting
bored, but also to make sure they can't get out! But even if
you have the budget, skills and experience to be able to look after
them, getting good information can be difficult.
That's where the new TFH book 'Cephalopods: Octopuses and
Cuttlefishes for the Home Aquarium' comes in. The authors are
Colin Dunlop and Nancy King; both experienced cephalopod keepers as
well as scientists. At well over two-hundred pages in length and
profusely illustrated with some of the best cephalopod photos
I've seen, at first glance at least this book set to be the
definitive textbook for those aquarists ambitious enough to keep
these amazing invertebrates. But does it live up to its
promise?
Science
Inevitably aquarists keeping animals as specialised as cephalopods
will be interested in their evolution and biology. The authors
introduce the cephalopods in the first chapter, taking care to
review the taxonomy of the group, outlining the key differences
between octopuses on the one hand and cuttlefishes on the other.
The many features that they have in common are described, and there
is also a brief review of the evolution of the group.
As the book progresses through eight chapters devoted to aquarium
husbandry and species selection, the scientific content is less
overt but remains significant. Anyone reading this book to find out
about the particular octopus or cuttlefish they own will quickly
absorb a lot of useful information on natural habitats, breeding
behaviour and so on.
Style
In general terms the book is written in a light but precise way,
very much in the style of a couple of jovial experts explaining
their subject to an audience of well-informed students. The book
does assume a certain amount of background knowledge with regard to
things like filtration and artificial seawater chemistry, but
that's obviously not a bad thing in a book aimed at a very
specific niche within the hobby.
One odd quirk is the flipping between metric and US units in terms
of priority. This likely follows on from the fact that one author
is a Scot and the other an American. It should be noted that this
quirk only applies to which units are given first in a particular
sentence: in all the cases I could find, even where (say) the
metric unit came first, the US unit would be presented in
parentheses. British readers should note that some US units are not
always identical to Imperial units, most notably in the case of the
gallon, where the Imperial gallon is significantly larger than the
US gallon.
Husbandry
As has been mentioned, neither octopuses nor cuttlefish are easy to
keep. No fewer than three chapters are dedicated to the issue of
building an aquarium that caters to their very specific needs. The
two authors are highly experienced cephalopod-keepers, and what
they present in the book is clear, relevant and above all
practical.
Refreshingly perhaps, the accent isn't so much on high-tech or
expensive equipment, but rather on getting the basics right from
the start, so that the aquarium you build for your octopus or
cuttlefish is finely tuned to provide the right water conditions.
Now, some marine fishkeepers may take issue with this approach. In
particular the authors advocate water changes as the prime tool for
keeping nitrate levels low, rather than things like the deep sand
beds increasingly widely used in reef tanks. They do also pass over
topics like alkalinity and redox potential that are considered by
many aquarists to be essential indicators of water quality.
But the other way of looking at this is to accept that this is a
book that, by definition, is aimed at expert fishkeepers. What the
authors are really doing is outlining the baseline values required
for cephalopods in terms of salinity, temperature, nitrate
concentration and so on, and leaving the aquarist to choose how
they want to go about providing these conditions.
On the other hand, where the authors go into great detail is when
explaining the things that make a cephalopod aquarium distinctive
compared to a generic marine aquarium catering to fish or corals.
For example, they explain why undergravel filters can't be
used, why protein skimmers are essential, and why you might want to
avoid lighting your aquarium altogether.
Decorating the cephalopod aquarium is a complicated topic, not
least of all because octopuses like to hide in rocks while
cuttlefish prefer to burrow into the sand. So if you want your pet
to feel at home, you'll need to follow the suggestions
presented here to provide it with a comforting environment. Making
the tank escape proof is another essential topic that the authors
cover in depth.
Feeding
Cephalopods are completely carnivorous, consuming little if any
plant material in the wild. Feeding them in captivity can be
difficult because they mostly prefer live foods, and generally need
quite a lot of food if they are to remain healthy, so the topic of
feeding these animals is of particular importance.
The authors spend an entire chapter discussing the nutritional
requirements of cephalopods. Initially they discuss the key issue
of how much to feed and how often, but then move on to what sorts
of foods can be used and how to obtain them. UK aquarists are
reasonably lucky in being able to buy live river shrimps from many
of the bigger aquarium shops. These are inexpensive and will
survive for several days in a tropical or subtropical marine
aquarium despite being coldwater animals in the wild. But if you
can't get hold of these shrimps, the authors describe lots of
alternatives as well, ranging from freshwater crayfish to live
clams.
With care, some cephalopods can be weaned onto frozen foods. The
authors describe the use of feeding sticks and other tools for
getting this useful job done. On the flip side, they also outline
the problems that arise when the wrong foods are used. Feeder fish,
for example, are not only too fatty to be safe to use, but can also
introduce toxic amounts of copper that have been used to medicate
the fish at some point. Copper is deadly to cephalopods, and even
small amounts will poison them.
Selection
The fifth chapter of the book is all about buying and acclimating
cephalopods. This is one of the most critical parts of the topic
because a lot of things can go wrong within the first few days. The
importance of the drip method of adjusting your new cephalopod to
the water conditions in the home aquarium cannot be overstated, and
the authors do a good job of detailing all the steps required to
make the adjustment. They also provide sage advice on things you
should and shouldn't do once your octopus or cuttlefish has
been turned loose in its new home. You shouldn't try to feed
your pet for the first day for example, and you shouldn't try
to play with your pet until it has had a couple of weeks to settle
down.
Octopuses are particularly sensitive to their environment, in both
positive and negative ways. Bright lights will scare them, but
hiding places will encourage them to settle down more quickly. The
authors describe a variety of toys that enrich the life of a pet
octopus, giving it things to explore and thereby avoid boredom. And
yes, octopuses can get bored, and at some level they need to be
stimulated if they are to remain happy and healthy in the long
term.
Enjoying your pets
Cephalopods can be enjoyed in many ways, and the authors
enthusiastically outline some of the ways they have enjoyed their
pets. Breeding cephalopods is one topic they discuss in depth, and
even those who don't have space to maintain sexually mature
groups of octopuses might care to raise octopuses or cuttlefish
from eggs. These can be ordered through your retailer, being quite
widely available from exporters and wholesalers.
An unusual but very worthwhile chapter explains the best way to
photograph your pet cephalopod. Given the relatively short lifespan
of most species, typically a year or two, most keepers will be
quite anxious to take some pictures, and the authors do a great job
of outlining the process. Being somewhat photophobic animals, there
is a bit of an art to taking the perfect octopus portrait!
The back end of the book contains various appendices including some
pretty off the wall stuff on cephalopods in art and literature.
There are lots of links to cephalopod-oriented web pages, as well
as a good list of useful books. People who are prepared to keep
octopuses and cuttlefish as pets are going to have to be pretty
dedicated given the demands these animals place on their owners,
but around the world there are actually quite a lot of those
people! If nothing else, this book makes it clear that if you think
a cuddly animal should have eight legs, two hearts, an upside-down
beak and be able to change its colour at will, you are not
alone!
Recommended?
Yes! As someone who has been lucky enough to work on cephalopods, I
was thrilled to receive this book for review. This is a
well-researched and well-presented book that stands remarkably well
as a practical review of the natural history of octopuses and
cuttlefish But what really makes it special is that the authors are
so clearly enthusiastic, intelligent and above all competent that
they make this challenging aspect of the marine aquarium hobby
dramatically more accessible than it was before the book was
written. It's a landmark book, and an essential purchase for
anyone interested in keeping cephalopods in captivity.
Copyright Neale Monks
We hope to have this book available on TFF within the next few
weeks and it is currently available from all major shops. |
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