This entire article is nothing more than my own personal
opinion. But that opinion has developed during my 13 years
of marine aquarium keeping as well as my 10 years of working
full-time in the ornamental fish industry. I offer it not
so much as a definitive statement, but as a guide to what
I go through and what I look for when purchasing fishes, and
as an aid to my fellow aquarists.
While I have attempted to thoroughly
discuss the most common diseases of marine fishes in an effort
to help fellow hobbyists save their aquatic pets once they
have already been purchased (see the list of additional reading
material at the end of this article), many problems with general
fish health and anomalous losses can be averted by careful
and critical selection of fishes at the time of their purchase.
The first thing to do is to decide which fish are desired.
I always advise clients to plan, with my advice and counsel
of course, every fish they are going to add before adding
the first fish. This prevents compatibility issues
later and saves the trouble of removing one fish from a fully
stocked display when it is later decided that another fish
is more desirable. Many fish don't get along well with others
of the same species or even with those of the same genus.
Knowing this and planning accordingly saves trouble later.
Second, once a wish list of desired species is developed,
further research is necessary. Will these fish get along?
Even if the aquarist is aware that he may have only one surgeonfish,
he may not realize that the planned yellow tang (Zebrasoma
flavescens) won't get along well with a foxface (Siganus
vulpinus), a raccoon butterflyfish (Chaetodon lunula)
or most other fish with a grossly similar overall appearance.
Consider compatibility among intended tankmates prior
to their purchase. The above two fish, for example,
are best not combined. Photos courtesy of Greg Rothschild
(left) and Tuan Pham (right).
Size - It is Even More Important than You Think:
After determining the compatibility
of the planned tankmates, the full adult size of the desired
fish should be determined. Purchase only fish that can be
kept in the display currently owned. In many instances, an
aquarist claims that he intends to purchase a bigger tank
sometime in the near future and will be housing this larger
animal in the relatively small display for only the next six
months to two years. Unfortunately, though, life happens.
People get laid-off. They get divorced and lose their house.
Any number of reasons might derail their planned upgrade.
And, because of this, the fish suffer from inadequate space
and, in some cases, poor water quality as a result.
Know Some History:
Three dead blue tangs and a fourth
one struggling for life. This certainly does not
instill a lot of confidence in purchasing fish
out of this aquarium in particular or from this
shop in general.
The next factor to examine is whether
the selected fish has historically done well in captivity.
Most hobbyists should realize that some fishes (and many other
ornamental marine organisms) offered for sale do not fare
well in captivity. Many have highly specialized diets that
are currently impossible to replicate. Others hail from cool,
temperate waters and do not survive long-term in a warm, tropical
display. Careful research before their purchase helps to avoid
these simple mistakes.
As more of an editorial comment, if we can't or won't police
ourselves, eventually the government or some other entity
will do it for us. The only reason we routinely see
obligate coral polyp-eating butterflyfish, remoras, baby nurse
sharks and other "dead fish - swimming" offered
for sale to uninformed, new aquarists is to make a quick buck
from an impulse purchase. This kind of shortsighted profit
taking does not do the hobby or the industry at large any
good. While it may appear that an endless stream of new "suckers"
enters this hobby every day, imagine the money generated if
most of these people were offered sound advice, good equipment
and healthy livestock, thereby making for successful, long-term
hobbyists. It is a shame that so many stores seem to operate
instead on the P. T. Barnum "a sucker is born every minute"
concept. And frankly, it is not a sound business model. Planning
not to maintain clients, but instead to turn over nearly
100% of customers every year, is a difficult proposition to
pull off. But, I digress.
Know Your Limitations:
Photo courtesy of Lisa Page.
I mentioned fishes whose diet cannot
currently be replicated, but there are others that can be
fed but which might be more challenging or consume more time
than the aquarist wishes to invest. Careful research beforehand,
as well as thorough and realistic introspection as to the
level of skill in aquarium keeping and the amount of free
time willing to be invested, can preempt these problems as
well. For example, mandarinfish (photo left) are certainly
not impossible to keep in captivity, but they are not for
everyone. They require larger displays with noncompetitive
tankmates and, preferably, a refugium to provide them with
sufficient live food. Again, careful research before
their purchase will help prevent needless livestock losses
and make for a more conscientious hobbyist.
During this research period, pay particular
attention to the diseases to which your potential tankmates
may be prone. Certain fishes are typically plagued by certain
pathogens. Surgeonfishes and puffers, for example, are routinely
afflicted with Marine Ich/Cryptocaryon irritans. Puffers
are also known to have problems with internal worm infestations
(Jedlicki, pers. comm.). In my experience, Acanthurus
species tangs frequently are stricken with both Marine
Ich/Cryptocaryon irritans and Marine
Velvet/Amyloodinium ocellatum. And, wild caught
clownfish are often afflicted with Brooklynella hostilis.
Knowing this prior to bringing the animal home helps during
its initial examination at the local fish store as well as
ensuring the aquarist is prepared by having the proper medications
on hand for treatment in the event the fish becomes ill.
At first glance this Kole tang appears to be doing well.
A closer inspection of this fish, however, reveals a
Cryptocaryon infestation. Photo courtesy of Bill
Additionally, it's important to research whether the fish
poses any danger to the aquarist. While most aquarists are
familiar with lionfish and stonefish envenomation,
and some know about the dangerous spines of foxfaces/rabbitfishes
and marine catfishes, there are other surprises as well. For
example, I was recently surprised to discover that scats are
venomous, and it's quite painful to be jabbed by their dorsal
Aquarists should pay attention to important details
when examining potential livestock. Left: Some
species, such as this Paracanthurus hepatus,
are prone to HLLE (head and lateral line erosion). Right:
This Chelmon rostratus suffers from a lesion
on its tail fin. Photos courtesy of Mark Kingery.
Captive-bred, Tank-raised or Wild-caught:
One last thing to inquire about is
whether or not the chosen animal is available captive-reared.
Whenever possible, I encourage fellow hobbyists to buy a tank-raised
specimen; they are generally far hardier and less disease-ridden
than their wild-caught counterparts. Consequently, this translates
into less work for the aquarist and makes for a better value
for the money spent. And, it is arguably a more environmentally-friendly
Local Fish Store Versus Online or Catalog:
Once all of the research is complete,
it is time to search for and evaluate the desired species.
This is probably going to be one of the most controversial
statements I make in this article, but I feel compelled to
say it. I don't understand buying fish mail-order or online
as a hobbyist. Frankly, I would not buy a pair of pants for
myself without first looking at them in a store and trying
them on, let alone purchase a live animal without evaluating
it firsthand. How would you know if they are going to make
your butt look big or not? Oh, wait a minute! I am supposed
to be talking about fish.
That is not to say, though, that I am against online sales
in all instances. There are certain things I would urge hobbyists
to purchase online or mail-order: live rock, for instance.
It does not make sense to pay a premium for something like
that. Significant discounts, even with shipping prices factored
in, can be had by buying online. Plus, the aquarist can obtain
a fresher product with a higher likelihood of creature diversity.
Other items, such as protein skimmers and lighting, are best
purchased via the internet because of the potential savings,
and also because of the range of choices available. How can
anyone expect a small "Mom and Pop" local fish store
to stock 175, 250 and 400-watt single-ended metal halide fixtures
along with 150 and 250-watt double-ended options in 6,500
K, 10,000 K, 14,000 K and 20,000 K lamps for all those wattages
and various manufacturers such as Ushio, Aqualine-Buschke,
Iwasaki, XM, Hamilton, etc., not to mention the myriad of
reflector and ballast options to be had? No store could possibly
afford the expense of stocking all those variations. But,
that is exactly what large warehouse vendors that sell through
mail-order catalogs or via the internet do so well.
While I prefer to purchase fish locally after first being
evaluated, I do not recommend purchasing fish from a store
that practices poor husbandry or routinely stocks animals
for impulse purchases that are historically known to fare
poorly in captivity. I don't give my business to stores that
prey upon the ignorant and uninformed, and I encourage others
to do likewise. Vote with your dollars and reward the good
local fish stores that are conscientious and run a clean shop.
Additionally, there are some areas of the country, unfortunately,
that because of their small population or remote location
cannot support a local fish store. As such, individuals living
in these areas are relegated to purchasing online or mail-order
exclusively. But, that is one of the beauties of the internet.
It can fill those voids in retail markets and can also help
consumers make good purchasing decisions. In these instances,
buying decisions should not revolve exclusively around availability
and price. Scour the internet looking for feedback
on the vendor that is being considered. There is no shortage
of people willing to volunteer their opinion online. Try to
sift through those opinions to find legitimate praise or positive
comment with regard to the quality of the animals received,
packaging, shipping and customer service in general.
When evaluating a specimen, the first
thing I want to determine is from where the animal hails.
Collection locale is extremely important when selecting healthy
livestock. Some places put more effort and money into collecting,
holding and shipping livestock, and while that extra care
comes at a premium in terms of its actual purchase price,
it pays off in the livestocks' health and vigor. Some places
that I am particularly fond of purchasing fish from include
Hawaii, Fiji, the Red Sea and Australia. Also, don't simply
take the word of the local fish store employee that the particular
fish being looked at actually comes from where he says. Sometimes
stores and their employees are simply misinformed regarding
the correct collection locale, and in some instances I get
the feeling that someone is trying to pull a fast one. Ask
yourself, do the price, coloration and known geographic distribution
coincide with the claimed collection locale? This takes a
bit of research on the part of the hobbyist prior to walking
into the store, but it is well worth it.
Knowing the fish's collection locale can also help an aquarist
avoid fish that have been captured using cyanide. Unfortunately,
is still a problem for marine ornamentals and the live
food fish industry. But it is currently limited to a few places
such as the Philippines, parts of Indonesia and I have recently
heard of it spreading to Vietnam. On the other hand, I have
never heard of any confirmed reports of fish coming from the
Caribbean, Hawaii, Fiji, the Red Sea, Australia or the Sea
of Cortez that are captured with cyanide, although I have
heard of other drugs being used such as MS-222, clove oil,
bleach and Quinaldine. But, I have not done enough research
at this time to discuss how widespread they are or their potential
Another thing to look for in fishes potentially caught with
cyanide is a dazed and confused appearance. The fish don't
interact with others in the tank, nor do they react to your
presence. A healthy fish should dart and hide when first approached,
but should be curious enough to come back out to see what
you are up to. Cyanide exposed fish typically remain motionless,
staring off into space. They also tend to appear overly bright
colored. I can best describe it as an aura, looking as if
the holding tank is illuminated with a lot of actinic lighting
when nothing more than standard full-spectrum lighting is
actually in use.
General Appearance & Behavior:
As part of observing its general appearance,
also examine the fish for spots, a dusty appearance, rapid
breathing (anything greater than one respiration per second),
red streaks, missing or damaged fins, cloudy or bulging eyes
or anything else that is out of the ordinary. I won't buy
damaged or obviously sick fish, and I would not recommend
that others do it either. That is not to say, however,
that a quick, cursory observation will allow aquarists to
avoid all sick fish. Several diseases are difficult-to-impossible
to detect from a brief observation because of the pathogen's
life cycle or appearance. That is why quarantine
is so critical. But, a careful observation helps minimize
the outbreaks and damage done prior to the chosen treatment.
This, in turn, helps to lessen subsequent losses.
Also, I pay particular attention to the mouth of long-snouted
fishes like butterflyfish and certain surgeonfish. In some
instances, these long-nosed fishes are damaged in transit
when bounced around in shipping bags. This is evidenced by
red streaks radiating out from the mouth or white "cottony"
looking growths on their lips. If any of these signs is evident,
I pass on that animal. To me, this is a double whammy. The
infection must first be dealt with while the fish typically
goes without eating. So, once the treatment is successful
and the infection has cleared up, the aquarist is still left
with a lean fish that needs additional "TLC" to
regain its normal weight.
A challenging fish that has also been damaged in transit
and lost most of its dorsal fin. This does not bode
well for long-term success with keeping this specimen.
Next, I like to see if the animal is eating. I won't necessarily
reject it if it won't eat the offered food, but it does factor
into my decision if it will, or won't, feed. Secondly, what
did it eat? Most any fish will consume live brine shrimp if
offered, but they might not survive and grow to a full adult
size on a diet of nothing but live Artemia. Fish that
are feeding on pellet or flake food are a much better risk,
in my opinion. Additionally, bear in mind that some fish probably
won't make the transition to prepared foods in the short time
they spend at the local fish store. Fish such as mandarins,
or gulping predators such as lionfish and groupers, are typically
going to require additional work to get them feeding on frozen
or dry foods. But, that is simply par for the course with
some fishes and something that was, hopefully, learned during
the research prior their purchase.
The Goldilocks Analogy:
The last aspect of physical appearance
to evaluate is size. While I have already mentioned researching
the full adult size of the fish in question, its size at the
time of purchase is also very important. Basically, I want
a fish that is neither too big nor too small. I want one that's
just the right size. I avoid all tiny, baby fishes - the ones
typically seen that are under one-inch long. Of course this,
like most any rule of thumb in this hobby, is simply a rough
estimate. It obviously does not apply to small fishes like
gobies, for example, that might not even grow to one-inch
as adults, but hopefully you get the basic point, namely,
avoid those that are exceptionally small. While these tiny
offerings are awfully cute and tempting, there is a tremendously
high mortality rate with these baby fishes. I have heard it
theorized that baby fish are probably like human babies in
that they need constant small feedings, which they don't get
while navigating the chain of custody from the reefs to the
final vendor. As such, they are probably half-starved to death
by the time they are offered for sale. I definitely see the
logic in that train of thought. While I don't know for sure
if that is why they seem to perish more frequently, they still
have a high rate of mortality, for whatever reason.
I also avoid very large specimens. These are the so-called
"show" fishes offered for sale. For one, they are
not a good value. Shipping large fishes is expensive because
they need a box all to themselves and require a lot of water,
i.e. weight, to go with it. Remember that much of the dealer's
final costs associated with a fish, and therefore its purchase
price, are the freight costs. Large bags of water drive up
the price of shipping a fish from point A to B.
Also, it often takes a lot of work to get these large fishes
to take prepared foods, assuming they ever do. Again,
I have heard people theorize that these large fishes are too
old and "set in their ways" to learn to eat prepared
foods. To me, that sounds a little too anthropomorphic. But,
I have seen a number of larger fishes refuse to eat for what
seemed like a longer period of time than their smaller counterparts.
It could simply be that these larger fishes, having searched
day after day for food while looking downwards at the substrate
for grazing material, have a hard time learning to look upwards
for food dropping from the heavens.
Play the Waiting Game:
Once a specimen has been selected,
one might wonder what is left to do besides taking it home.
But remember that you are paying a premium from the local
fish store because of its potential losses, along with other
associated costs. Let that work to your advantage. Place a
deposit on the fish you want, and let it sit for three to
seven days before actually purchasing it. Morgan Lidster has
spoken and written about something he calls "Post Traumatic
Shipping Disorder." Additionally, Edward Noga has written
about something he calls "Delayed Mortality Syndrome"
(Noga, 2000). Both of these phrases characterize similar phenomenon.
Basically, these terms mean a fish may die from any number
of reasons related to shipping trauma; things such as temperature
changes, lack of oxygen, depressed pH, salinity shock, etc.
None of these stresses are readily apparent upon physical
examination, though. So, by allowing the fish to acclimate
for up to one week in the dealer's tank, I can be reasonably
sure that the fish won't keel over at a later date from unexplained
reasons when I bring it home.
Whenever I see a dead fish in a retail outlet, I automatically
suspect the store. Some fish are going to die no matter
what; losses are a part of working retail. But, leaving
them in the tank for customers to see makes you wonder
if other aspects of their husbandry get neglected as
well. Not to mention it leaving me wondering why they
died in the first place and why the store didn't catch
the early symptoms and treat accordingly.
Again, like most rules regarding aquarium keeping, there
are exceptions to this rule. In the case of fishes
such as dragonettes, seahorses, pipefish and other frequent
feeders, I take them home as soon as possible. Simply put,
I trust the care I can provide for these challenging fishes
more than that provided by any local fish store.
Hopefully, most will find this guide
to be useful. I have tried to lay out in a systematic way
the processes that I go through when purchasing a fish, even
though I don't have a true checklist, either literal or mental.
I do many things when evaluating a fish that are almost subconscious,
honed from years of experience. In time, you too will learn
and perform this sort of analysis without even thinking about
it. In the meantime, use my advice as a guide to enjoying
this hobby even more.
All photos copyright Steven
Pro, except where otherwise noted.