by birdfish
I.O. is the way to go!
In marine fishspeak I.O. stands for Indian Ocean. It is most
often used to differentiate the fish that did not come from
the Pacific Ocean where most of the fish out there came from.
The fish from Bali, the Philippines, Fiji, Hawai'i, and much
of Indonesia (and Bali) are Pacific Ocean fish. The main I.O. source
historically has been Sri Lanka, or as when I was young it
was called Ceylon. Most of the I.O. fish over the last several
decades were of Sri Lankan origin. There have been a few
other intermittent sources of minor import from time to time.
The Indian Ocean is one of what are called the world's three
great oceans, with the Pacific and Atlantic. It is the third largest
ocean in the world, with about 20% of the world's ocean area.
It extends from Australia to Africa, and north to Asia. Its northeast
corner is roughly Indonesia. The west side of Indonesia is I.O., to
the east is the Pacific Ocean. In the geographical heirarchy of oceanic
or marine features first you have oceans, in or adjacent to which you
may have seas, then gulfs, and finally bays.
The Red Sea is considered a sea of the Indian Ocean, as is the
Arabian Sea. Then you have gulfs, such as the Persian Gulf, and the
Gulfs of Oman and Aden. Finally then bays, like the Bay of Bengal,
which is ginormous by bay standards, the largest bay in the world.
The bay in the name is a misnomer really as it is not protected as
typical bays are, in fact much is open ocean, so it should have
been called the Bengal Sea or Gulf of Bengal, but I guess those
just didn't have the ring Bay of Bengal did.
Not only is the Red Sea considered a sea of the Indian Ocean, few
realize a number of fish usually called 'Red Sea' fish are
actually found in the immediate adjacent Persian Gulf, Gulf of Aden,
and Arabian Sea of the far western Indian Ocean too. A few examples
are the amazing Red-faced Butterfly (Chaetodon larvatus), Asfur Angel,
and even the Purple Tang, among others. Fishing in the Persian Gulf is
a bit dicey these days. Lately getting things out of the Red Sea is like
pulling teeth and these other sources have been supplying a bit of
'Red Sea' fish (from the I.O.) mostly via Yemen and Somalia.
The thing with I.O. fish is that the Indian Ocean versions of
many widespread fish are brighter in color than the Pacific Ocean
fish of the same species. In some cases there are 'super-species'
which is a group of very similar closely related species, with I.O.
versions having full species status, others are just sub-species,
still others are varieties or color morphs, of often widespread species.
The brighter coloration aspect of I.O. fish is consistent across many
families of fish. The I.O. version is always brighter. What is up with that?
The example most of you know is Blonde Naso Tang versus the regular
Pacific Naso Tang. Blonde Naso are the I.O. version of the standard
Pacific Naso Tang. Most would say prettier, brighter, and more
colorful with that bright orange dorsal fin. And so it goes with
many species in the I.O. Gold-striped Maroon Clownfish is another
example many know, in general white-striped Maroons are Pacific,
while I.O. Maroons are gold-striped (more color - prettier).
In many cases, both I.O. and Pacific varieties are all considered one
species, as best I understand it. Some others are considered different
subspecies. Some are full species, and some I look at some and wonder why
they don't have full species status. I am not a taxonomist though and
so won't play one on the intertubes. I think many of the I.O. forms are
just considered color morphs or color phases. By the way, generally for
most biological usages a morph is permanent, a phase is temporary, so these
would be I.O. species, subspecies, or morphs, as the case may be.
Some other great examples of the I.O. differences are the Imperator Angels,
orange-tailed in the I.O. version, yellow-tailed in the Pacific.
Regal Angels are white-bellied in the Pacific, yellow-bellied in the
Indian Ocean. Then I.O. Blue Tangs are also yellow-bellied when they get size,
the Pacific Blues are blue or white bellied. I always thought the I.O.
Odonus niger trigger was bluer, whereas the Pacific ones are greener.
One of my favorites that I once kept was the I.O. Teardrop Butterfly,
all yellow bodied with none of the white that the Pacific fish (formerly
mostly from Hawai'i) is. What a great fish, a beautiful animal. The
I.O. Teardrop is often considered a seperate species from the Pacific
Teardrop (I.O. is Chaetodon interruptus versus the Pacific C. unimaculatus)
and illustrates why binomials (scientific names) are so useful. Now if
it is correctly a full species is another story. Having kept and studied
both my vote is yes. In any case I sure like having an absolute different
name to call it where we can all be on the same page about which animal
exactly we are talking about. The point of binomials. Or if a designated
subspecies, the trinomial does the trick.
There are also many sibling or sister species to widespread Pacific
fish that have I.O. endemic versions. Like I.O. Coris formosa vs. the Pacific
C. gaimard wrasses (young nearly identical, adults way different). The I.O.
Gomphosus caeruleus vs. Pacific G. various (blue bird vs. green bird wrasses).
Another is the I.O. Zebrasoma desjardini vs. the Pacific Z. veliferum Sailfin Tangs.
All are widespread Pacific Ocean species with a brighter sister taxon endemic
in the I.O. (though adult Red gaimard wrasses hold their own against anything).
There are of course lots of I.O. endemics, stuff that isn't found
in the Pacific Ocean. Things like xanthocephalus, melapterus, madagaskariensis,
mittratus, and amazing collare butterflies, chrysurus angels, Gem Tangs,
Tesselatta (favigineus or permistis) eels, radiata lions, M. indicus triggers,
good groupers (sometimes flavocaeruleus and often boenacki), the best annularis
angels. All are I.O. fish. Some might be found a little in the Pacific,
but where to get them are the Indian Ocean sources.
The Sri Lanka I.O. Powder Blue Tangs were always considered far
superior to the Bali and Indo fish, though for hardiness rather
than any visual difference one might find. No contest. Can't tell
them apart to look at them. Sri Lanka put itself on the map decades
ago because the Powder Blue Tangs (PBT's) from there lived forever.
As opposed to the Bali or Java (Indo) PBT's that can have longevity issues.
There is way more freight on I.O. PBT's since further away (packed way
lighter), so they cost way more and then they don't sell. Instead, people
say PBT's don't live long because they are accustomed to dealing with
the cheaper Bali-Indo fish, which, based on how they thrive in captivity, is
a completely different animal. It sometimes seems like we have forgotten
things we already had figured out.
Some few things along the east side of the I.O. end up for sale
via Bali, Java (Indo), and Irian Jaya where things from the furthest
west reaches of their collectors can come from the eastern-most
Indian Ocean. But only a few of the items, like annularis angels,
gold-striped Maroons, Blonde Naso (Orange-spine Unicorn on their lists),
and Yellow-bellied Regal Angel. Those are I.O. and they cost more.
Actually Irian Jaya is the spot that most regularly gets some I.O.
from the west end of their island (Papua New Guinea) that reaches
eastmost Indian Ocean waters, but even then it is only a few items.
You need to get to Sri Lanka or Kenya to get into the heart of the
I.O. difference and a stock list full of species not on Indo-Pacific lists.
One more example of the I.O. difference is with female Anthias of
the species Psuedanthias squamipinnis. On the Irian Jaya list they
are available regular, which is dark eyed Pacific fish. Or you can
order the blue eyed Indian Ocean version (for about four times as
much per fish). There are surely countless examples of these types
of differences, we are only scraping the tip of the iceberg here to
give you an idea of the magnitude of what is going on.
OK, I'll come clean with full disclosure, I once had an I.O. tank.
That's right, every fish was I.O. I was an I.O. snob. LOL

But the stuff is so neat, and there were a bunch of bad Philippine fish
goin' round at the time. Sure the I.O. were more, but I knew they were
better fish, the real deal. As an I.O. freak, througout the 1990's next to
my desk on the wall was the classic Nat. Geographic map (from the 1970's?)
of the Indian Ocean showing the seafloor, all the geography of the I.O.
above and below the sea. Must be still packed in a box, haven't seen it.
You might be able to find one of those, it is stunning.
We know anywhere I.O. everything is hand or net caught, and kept for a
good period in tanks and likely eating for a week or two until just before
shipment (because flights and shipments are not as regular). At the
wholesale importer end I.O. fish in general have long been considered
like those from the Red Sea and Australia, they eat-out-of-the-bag and
possess bulletproof hardiness. The hand-caught and cared for difference.
There have always been good inverts from the I.O., particularly Sri Lanka.
The biggest best skunk or eel cleaner and fire shrimp (called pinkies
for the size), great colored carpet anemones (rarer and higher priced now),
crimson knob stars, and sea lillies if you want to try something really
exotic (amazing animals for very advanced aquarists). Kenya too has
good I.O. inverts.
Currently I.O. fish are available primarily from Kenya and Sri Lanka.
Besides sharing a number of the I.O. specialties, each has different
things too, like Chrysurus Angels often at Kenya. There are some few
fish from the Maldives and 'Red Sea' available via a Sri Lanka source.
Sri Lanka imports some Red Sea and Maldive Island fish to their station
where we can tap into it and they ship everything together from there to
LAX. So you can get some deluxe stuff like Purple Tangs. Sri Lanka has
historically been a wee bit sloppy with a sub here and there. You might
get an extra 3" Powder Blue Tang you have to find a home for. It
is their favorite fish to send as a box filler - their idea of a 'damsel.'
Dealing with extremely foreign places on the other side of the world
requires a small amount of flexibility. It is the only way to get a lot of good stuff.
The Red Sea and Maldives is a bit high, but they have to fly
them in from those areas and tank and keep them until they are shipped.
If you check the Sri Lanka-Maldives-Red Sea species list out, you will
see lots of things not generally widely available. Always note the
current stock column to see if they have it, the Kenya and Sri Lanka lists
are full master lists with the current stock column critical for current
ordering. Note that things they only show one or two of, we can't be
guaranteed to win the lottery on and receive.
Just to remind like all of our sources, of course you can't get a
half box of each source, you have to make up a box worth of fish from any given
source (or all of them

). We are not the
place for a couple or few fish unless big box fillers.

If you are getting mediums, Sri Lanka runs 6-12 fish in a box,
Kenya about 15-20, of course way more if all smalls (double it).
Some of the neat different Kenya I.O. fish available from Africa
are allardi and chrysogaster clownfish, acanthops Pygmy angel,
often Chrysurus Angel, Lyretail Hog, great butterflies including
madagascarensis, I.O. Yellow Teardrop, and zanzibarensis, a bunch
of great wrasses like Coris angulata and formosa, H. iridis Radiant
Wrasse, bipartitus Divided Wrasse, Bluestripe Pipefish, flavocaeruleus
grouper, it's a whole 'nother world, African Indian Ocean!
Once a year or two, if we are lucky, a load of Gem Tangs comes in
from Zanzibar to the Kenya station and you can get them for a week
or two. If you have a few grand burning a tang hole in your pocket. LOL
At least with I.O., there is usually never anything you can't get
rid of. Most stores don't carry it because it cost more.
At the retailer level an extra $5-10 for a fish and 10-15 bucks extra freight
for what looks like the same little juvenile Imperator angel... they
usually opt for the cheap one. You can't tell it is going to be an
orange tailed adult, you have to know. You can't tell when it
is small that the I.O. Blue Tang is going to grow up to have a yellow belly.
So most opt for the cheapest one, or as often, the only one at hand, understandably.
I have long been a huge fan of Indian Ocean fish and fauna, primarily intrigued
with the many unique endemic species, subspecies, and color varieties of fish.
Why is all this stuff different in the Indian Ocean? What's the deal?
It well illustrates how unique the Indian Ocean is. When not sibling species
of a species pair, there are unique color forms of so many Pacific species it
is mind-boggling. I don't pretend to know them all and would be interested
to hear of other examples folks know of. Mostly here we have just discussed
a few of the most common obvious well-known examples you are likely to see.
The oceans may look similar from above, and are even connected, but to
compare the fish from inside them, the differences are astounding.
Vive le I.O. différence!