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Freshwater Fishes of Southeast Asia
Potential for the Aquarium Fish Trade and
Conservation Issues
Southeast Asia is a conglomerate of continental
landmasses and numerous islands, all of which lie within the
equatorial belt. Composed of the countries of Thailand, Malaysia,
Indonesia, Singapore, Brunei and the Philippines, the year-round
warmth, high humidity and light of the region has resulted
in an environment which is extremely diverse and varied in
habitats (Whitmore, 1986). The freshwater fish fauna of this
region is exceptionally diverse, and over 1000 species are
now recognised (Kottelat et al., 1993) from western Indonesia
and East Malaysia (Kottelat et al., 1993; Kottelat & Lim,
1995). 
It is thus not surprising that the lucrative
aquarium trade has been utilising numerous wild species in
Southeast Asia for many years. The number of species which
are traded, however, is
surprisingly small, despite the large number of species present.
Much of the "official" trade has been with farm-bred
species like guppies, goldfishes, kois, mollies, swordtails
and cichlids, none of which are native to the region. While
a great deal has been written about the trade of these species,
much less is known about the wild fish trade. As with any
natural resource, there are several conflicting points of
view about using this resource. Economics dictate that the
trade should be expanded, with more species and larger quantities
exported. Conservationists argue that such a resource should
be left alone and conserved while sentimentalists argue that
trade of live animals is inhumane and should be banned outright.
Reality, however, requires that a compromise be established.
The trade itself is an enormous one. Singapore
itself exports US$80-90 million worth of fish every year.
While the bulk of this trade is due to the sale of cultured
species, an increasing part of it includes the re-exportation
of wild-caught fish. It is also generally acknowledged that
the actual trade, even for Singapore, is probably several
times the official figure. There are few reliable figures
for the other countries as well, and official figures are
often a gross underestimate of the real total. For Southeast
Asia as a whole, we estimate a total trade of between US$300-400
million in aquarium fish species in total.
The present paper is an attempt to place
some perspectives on the booming regional aquarium trade in
wild fish species. We will focus on an overview of the trade,
the problems faced and the practical conservation issues on
hand which must be dealt with squarely. We will also look
at a few key species which are currently important for the
trade, mistakes which have been made in the past, potential
for the trade and common misconceptions about it, as well
as offer suggestions on how this resource can be managed sustainably.
The present observations and suggestions are based on many
years of working closely with fish catchers, dealers and exporters
in the region, not only on a scientific level but also at
the fisheries level. There is so little published information
that we feel that it is imperative that some of these observations
be put on paper.
Species in the trade
The wild-caught species currently traded can be approximately
divided into three categories on the basis of how important
they are to the trade.
Category I are the so-called "bread
and butter" species are those which are very popular
in the trade and are caught and exported in large numbers.
Examples of wild-caught bread-and-butter species from Southeast
Asia are:
clown loach (Botia macracanthus),
eel-loaches (Pangio spp.),
chocolate gouramy (Sphaerichthys osphromenoides),
pearl gouramy (Trichogaster leerii),
harlequin rasbora (Rasbora heteromorpha),
flying fox (Epalzeorhynchus kalopterus),
lancer (Luciosoma setigerum),
two-spot catfish (Mystus bimaculatus) and
glass catfish (Kryptopterus bicirrchus).
Category II are wild-caught species which
are traded occasionally or in small numbers at the moment,
but with a good potential for their increased popularity and
export are:
neon rasbora (Rasbora axelrodi),
Hasselt's goatfish (Osteochilus hasseltii),
glowlight rasbora (Rasbora pauciperforata),
graceful rasbora (Rasbora gracilis),
Hengel's harlequin rasbora (Rasbora hengeli),
kalbar rasbora (Rasbora kalbarensis),
red rasbora (Rasbora reticulata),
six-banded tiger barb (Puntius hexazona),
zebra barb (Puntius gemellus),
eyed tiger barb (Puntius rhombocellatus),
eight-banded barb (Eirmotus octozona),
filamentous glassfish (Gymnochanda filamentosa),
fire-eyed loach (Barbucca diabolica),
swamp loach (Neohomaloptera johorensis),
Hasselt's loach (Lepidocephalichthys hasseltii),
Bornean clown catfish (Leiocassis mahakamensis),
brown clown catfish (Pseudomystus fuscus),
glass catfishes (Pseudeutropius spp.),
red dragon eel (Mastacembelus erythrotaenia),
fighting fishes (Betta spp.) and
licorice gouramies (Parosphromenus spp.).
Category III species are those which are
very expensive and cater for the "high end market".
Species in this category include:
arowana (Scleropages formosus),
red-flag giant gouramy (Osphronemus laticlavius) and
sawfish (Pristis microdon).
It is important to note that other than foreign species (like
guppies) which are now cultured, a number of native species
have also been so exploited. These include:
Siamese fighting fish (Betta splendens),
kissing fish (Helostoma temminckii),
gouramy (Trichogaster trichopterus),
bala shark (Balantiocheilos melanopterus),
scissor-tail barb (Barbodes altus),
tiger barb (Puntius tetrazona),
walking catfish (Clarias batrachus) and
giant catfish (Pangasius sutchi).
Most of these species have been selectively bred over the
years with the result that there are now a large number of
different breeds of each.
There are several well publicised examples
of severely over-exploited species, e.g. the bala shark (Balantiocheilos
melanopterus), arowana (Scleropages formosus) and
harlequin rasbora (Rasbora heteromorpha). Some of them
had been overfished to the extent that they have become locally
extinct. The classic case must surely be that of the bala
shark (Balantiocheilos melanopterus).
Bala shark (Balantiocheilos
melanopterus)
The bala shark was once abundant in Sumatra
and Kalimantan, and was a classic Category I species. Despite
its simple coloration, it became very popular all over the
world as an aquarium fish. This popularity resulted in severe
overfishing which effectively exterminated the wild populations.
It may well be extinct in these areas. The species became
so popular in the trade that it became one of the most important
species in the trade. In addition to extensive and intensive
collections in the various drainages where it was known to
occur, the collectors apparently also discovered the breeding
grounds. The bala shark also apparently migrates to reach
specific breeding grounds where it undergoes mass spawning.
This species reaches sexual maturity at about 10 to 15 cm,
although it can reach 25 cm in length. All sizes which could
be marketed were harvested, including juveniles and adults
up to 15 cm in length. The collections thus took a serious
toll not only of juveniles but breeding adults as well. This
species also happens to be a relatively delicate species,
being "jumpy" and easily excitable. Their fishery
thus often results in high mortalities. That the species is
relatively short-lived means that regular large collections
of specimens for the trade is necessary, and that capture
of breeding individuals has very serious consequences for
the population. These factors, together with collections even
when it was reproducing at its breeding grounds, not surprisingly,
resulted in a sharp drop in its numbers after a few years.
Undoubtedly, deforestation was also partially to blame, but
the key factor which led to its demise must surely be overfishing.
The species has had a "second chance"
as fortunately, wild populations in Thailand were still intact.
While the wild population in Thailand is dwindling, the species
has been bred in captivity. The success of captive breeding
has meant that the trade in this species (which remains very
popular) is today based almost entirely on cultured fish.
Arowana (Scleropages
formosus)
The arowana is widely distributed in Southeast
Asia - Cambodia, Peninsular Malaysia, Sumatra and Borneo.
There had been local extirpation of Scleropages formosus
in some drainages in Peninsular Malaysia and Sumatra due to
over-collecting, but is still relatively common in some areas.
This species has all the features of a Category III species
- high value, high demand, relatively initial abundance in
the wild. Its biological attributes (low fecundity, oralbrooding
habit and being an open-water spawner), however, make it a
prime candidate for over-exploitation and possible extinction.
Unlike the market for the bala shark, that
for the arowana is somewhat different. The high cost of each
fish, even juveniles, means that it is not a species which
is exported in large numbers and to average aquarists. For
many years, the arowana was only occasionally seen in the
aquarium trade and the species appeared regularly in markets
as a relatively cheap food fish! Its sudden popularity was
basically an Asian phenomenon. At some stage, Chinese superstition
had it that keeping this fish gave its owner good luck and
prosperity. This belief probably partly arose by chance and
partly because of the bright red and deep gold colours of
some arowanas, which Chinese and Japanese associate with luck.
Suddenly, people (especially businessmen) were paying incredible
prices to own an arowana so as to have a good luck charm.
In the west, the Southeast Asian arowana (and the South American
species) are much less popular, although they appear in the
trade occasionally.
The relatively smaller market and much higher
individual price of each specimen has meant that the stocks
of wild arowana had been less stressed over the short term.
Also important is that the arowana individuals are territorial
and are dispersed over a wide area, making their collection
difficult. Neither do arowanas migrate or congregate when
breeding, thereby reducing risks to their populations. In
addition, arowanas are relatively long-lived fishes, often
adapting well to captivity, and are usually kept in solitary
tanks. The turnover of arowanas is thus very small compared
to species like the bala shark. Concurrent with the rapid
development of the trade of the arowana of course, was the
realisation that the fate of the species might be threatened,
especially considering its reproductive biology. This resulted
in the species being placed on the CITES list of protected
species relatively early. Although CITES is usually ineffective
in many areas, it nevertheless served to restrict the trade,
and most countries have tried to curtail the trade, even if
it is often at face value only.
The large size, mouth-brooding behaviour
and high price of arowanas have also spurred efforts for their
culture relatively early. In the Kapuas area in western Kalimantan,
Indonesia, large farms have been established where the arowana
has successfully being bred. Under CITES guidelines, once
an endangered species can be bred in captivity, applications
can be made for its trade to be allowed on a controlled basis.
In Singapore, the successful spawning of the second generation
of Scleropages formosus by Rainbow Aquarium Pte Ltd.
and the Primary Production Department (PPD) of Singapore has
also lead to the controlled sale of this species. The usage
of microchip implantations into these Singapore offspring
aids in the identification of legal stocks in the trade. However,
wild caught specimens still command good prices (depending
on the colour variety) and are in high demand, until at least
captive bred stocks can meet demand. There is still an extensive
illegal trade ongoing (pers. comm. with fish dealers). The
prices of the different colour varieties of S. formosus
differ greatly. The red and gold varieties can cost from five
to ten times more than the green or normal variety (pers.
obs.).
It is also important to put issues in perspective.
Ten years ago, ad-hoc attempts at captive breeding of arowanas
were generally viewed with scepticism. Time, technology and
dedication of fish breeders have made this a reality. It is
currently heading towards the stage of full commercialisation
of breeding arowanas in farms. Perhaps in 10 years time, there
will be no more need for the harvest of wild stocks, except
perhaps for the occasional specimens to supplement captive
stocks to improve their genetic composition. There are also
problems with the taxonomic status of Scleropages formosus.
The different colour varieties may well represent different
species, but there are insufficient preserved specimens with
good data for the necessary comparisons. The high price and
CITES status of Scleropages formosus also hinders further
taxonomic work.
The clown loach, Botia macracanthus.
Small specimens are important for the aquarium trade whilst
large ones are sometimes sold for food. This is one of the
most popular fishes in the trade and is a clear Category I
species. Juveniles are found in abundance in the large rivers
of central Sumatra, west Kalimantan and central Kalimantan
during the high water seasons. The adults breed at the beginning
of the high water season and locals catch the young soon after.
This is the only time in the year when the fish is caught.
At other times, the individuals are too dispersed, scattered
or large to be of value to the trade. The size range preferred
by aquarists is three to eight centimetres. Larger specimens
tend to be more carnivorous and do not fit in well in community
tanks. Adults can attain sizes up to 40 centimetres long.
The most commonly marketable size range is from two to four
centimetres in length, with the optimum at around two cm.
This is because it is at this size when most individuals are
caught as they come downstream from their breeding grounds
upriver. At this size, they are also easier to maintain in
captivity and is easily fed with available fish feed.
The current trade in this species is estimated
to be about 20 million pieces exported annually. According
to a major dealer in Sumatra, handling up to one million pieces
annually is common. It is important to note here that while
the minimum breeding size of this fish is about 20-30 cm,
the trade is only interested in much smaller individuals.
As such, the fishes caught are basically juveniles, and breeding
populations are left intact. This is possible also due to
the current method for catching these fish (see later) which
pre-select for the sizes to be caught. The breeding grounds
are not yet known and even if discovered, it is unlikely that
there will be any fisheries directed here as the individuals
would be too large anyway. In any case, Indonesia has imposed
a ban on the export of specimens larger than 10 cm in length.
This ban, not only protects breeding adults, but also makes
the captive breeding of this species by external agencies
more difficult. Some dealers now culture clown loaches. Often,
fishermen are able to trap individuals smaller than two cm.
These are cheap and too small to be marketable but if they
are grown out, a profit of up to 300% or more can be realised
if a juvenile of 1.5 cm is raised to 3 cm. Juveniles exhibit
incredible growth rates. A doubling in size is discernible
in a week, if sufficient food, adequate aeration and filtration
are provided. Some exporters also keep excess stock to grow
out and sell later at higher prices when the fish is not in
stock and prices are high.
Collection of Botia macracanthus is
slightly different in Borneo and Sumatra. In Sumatra, Botia
macracanthus are caught by using perforated bamboo poles
stuck into the river bank substratum. The perforations are
situated just below the nodes of the bamboo pole, and the
size of the perforations will determine the occupant size.
To obtain fish of a certain size range, the correct perforation
size is made. This will catch fishes up to that size. The
collector sticks these poles at regular intervals of about
one metre apart in the river substratum. During the peak season,
the collector will collect at regular intervals by lifting
the whole pole out and pouring out the contents into containers
or directly onto the boat's bottom, which is filled with water.
Later, the catch will be sorted and transferred into holding
tanks, before selling to a middle man. In Borneo, a variation
of the abovementioned technique is used. A bundle of trimmed
and split bamboo poles of a pre-selected diameter are tied
together and sunk with stones. The bundle is attached with
a rope that is tied onto stakes driven into the river substratum
or onto overhanging bankside tree branches. Fish will take
refuge in and amongst the bamboo poles. The collector lifts
up the whole bundle and shake out the refugees into a container.
This technique used is somewhat more stressful to the fish,
as they are shaken out. The technique used in Sumatra only
requires pouring out the contents, and thus less harm inflicted
on the fish.
The clown loach has been heavily exploited
in Sumatra and west Kalimantan for over 20 years now, but
can still be found in good numbers in the wild. The reasons,
as mentioned earlier is due mainly to the nature of the fisheries
and the market, and to a lesser extent on government guidelines
which controls its trade.
In Central Kalimantan, the exploitation of
B. macracanthus is not as heavy and the locals catch
adults for food (pers. comm., D. Siebert, BMNH). Specimens
from Sumatra can be discerned from the Kalimantan specimens
by the fish exporters. The overall colour is subtly different
between the populations. The Sumatran specimens generally
have a silvery sheen over the body; whereas the Kalimantan
specimens have a more intense reddish colouration. This could
however due to the habitat. The Sumatran specimens inhabits
murky water rivers, whereas the Kalimantan ones prefer brown
water rivers or even black water tributaries. The dissolved
tannins and humic acids in black water tend to accentuate
their reddish colours.
Captive artificial breeding of Botia macracanthus
is possible and has been accomplished by the Thais. However,
it is still not cost effective to captive breed them, with
the wild caught stock being much cheaper. The species has
some unusual breeding characteristics and it is not one of
the easiest fish to breed in any case. The technology must
be developed to be commercially viable, in order to take pressure
off wild stocks. The trade must have enough foresight to counter
the inevitable extirpation of wild stocks. If the technology
has not been developed in advance, then the whole species
may face extermination due to unscrupulous fishing methods,
and more worrying, habitat destruction.
The harlequin rasbora is found in abundance
only in swamp forest habitats in Peninsular Malaysia and the
northern half of Sumatra. It is a Category I species, commanding
a reasonable price but often in large numbers. The species
has been popular in the trade for many decades and is popular
in community tanks.
The collection of this species in the swamp
forest is a tedious process, because the specimens are literally
scooped out individually or in groups. Although this is a
schooling species, the dense vegetation and uneven terrain
of the swamp forest makes collection generally difficult.
However, this species has been found to occur in more disturbed
areas, e.g. Pulau Bintan, where shoals can be scooped out
in large numbers (pers. obs.). Fortunately for the trade,
but unfortunately for the fish, school children love to spend
their spare time catching fish and earning some pocket money
at the same time. Middle men seek out eager helpers to collect
harlequin rasboras and pay by lots of a hundred or by per
piece. These specimens are collated and collectively sold
to the fish dealer. During a major harvest, in excess of a
hundred thousand pieces can be obtained within a week (pers.
obs.). This fish is easier to catch during the low water season
when the fish population is concentrated in shallow pools
of water. This is in sharp contrast to the fisheries for the
bala shark, arowana and clown loach, which are predominantly
fished from large rivers, requiring boats and at least some
expertise at fishing.
Ironically, harlequin rasboras are not very
prolific breeders. Their endurance in the trade, despite the
extensive collecting efforts is due in no small part to its
very extensive distribution and difficulty in collecting them
enmasse like other species. Even as schooling fish, harlequin
rasboras are not present in huge numbers. That the species
is still extant, even abundant in some places means that the
current fishing practices are sustainable. As will be noted
later, the primary fishing period for this fish is during
low water periods when the fish are accessible. Shortly after
this period, the populations often collapse in any case due
to a shortage of water. For this species, we anticipate that
the rapid loss of forests (especially swamp forests) will
pose the greatest threat to its survival, not the aquarium
trade as it stands.
It is our opinion that freshwater fish can
be sustainably harvested, unlike some other vertebrates, as
long as sufficient tracts of their natural habitat (including
the breeding grounds) are conserved. This is in part to the
nature of fishes and their habitats.
Annually, two phases occur in the wild -
growing and collapse phases (see Goulding, 1989). Typically,
the growing phase is just after spawning during the high water
season and juveniles are plentiful. This phase is vulnerable
to both inter- and intra-specific competition and predation.
This is the phase in which certain species can be harvested
with less immediate and direct impact to the long term survival
of the population, e.g. in Botia macracanthus. There
is also usually a "population collapse" phase which
typically occurs during the dry or low water season. This
is the phase in which many individuals die out due to lack
of water and other resources. This is a particularly appropriate
juncture to harvest, not only because many of the fish will
die anyway, but also it is relatively easier for fishermen
with the waters being low. Most species of tropical freshwater
fish are not annual fish, and the typical lifespan of the
smaller fish is anywhere from two to five years or more. Therefore,
fish collected during the collapse phase, while benefiting
the trade and hobbyists, is not anticipated to have much impact
on the population of the species. Its effect on the ecosystem,
however, is less clear, but we doubt if the impact is very
great considering the small size of the fish and many other
non-aquarium species involved. As such, we believe that as
long as the fisheries of selected species is coupled with
proper harvesting techniques, high mortality rates and the
threat to the survival of the species can be avoided, e.g.
in the harvest of Botia macracanthus. It is important
to be more clinical and management-oriented when decisions
need to be made on how a fisheries can be made sustainable,
on the threats faced by each species and the nature of the
trade. From the examples provided of the bala shark, arowana,
clown loach and harlequin rasbora, it is clear that the trade
and conservation of each species differs. Conservation and
fishery practices must thus be specifically tailored to deal
with each set of problems.
It is also important to note here that the
sustainable utilisaton of aquarium fish resources is an important
factor to consider when forest conservation in general is
considered. The economic value of conserving forest systems
usually involve calculations of forest products and by-products,
almost always leaving out the value of aquarium fish. This
sustainable by-product of an intact forest can add substantially
to the overall calculations.
The morality of the trade is another question
altogether. Care is increasingly been taken to minimise mortality
in wild-caught fish and substantial progress is being made.
The actual catching process has improved over the years, and
middle men are increasingly emphasising to their catchers
that good quality fish are needed. Gone are the days when
only numbers matter. The nature of the aquarium market today
(especially in western countries and Japan) is that high quality
fish are wanted, even if prices are somewhat higher. With
improved catching methods has also come the realisation among
many dealers that wild-caught fish must be acclimatised before
export. This is to ensure a high percentage of survival on
arrival. Concurrent with this is improvement in packing technology
which allows high stocking densities for longer periods. This
involves not only technology and water quality but more knowledgeable
use of appropriate anaethestics and chemicals. Freshwater
fish in general are not very fastidious and are relatively
easy to acclimatise, so long as one critical detail of its
place of origin is known - habitat type. As an example, fish
from peat swamp habitat should be acclimatised in water pretreated
with peat or a local equivalent (e.g. dried leaves of Terminalia
catapa) to make it sufficiently acidic. The transit of
fishes through right channels also decreases the time between
packing and unpacking on arrival at its destination. The improvement
in transport arrangements and choice of export point (e.g.
airport used) are very important considerations.
In Southeast Asia, Singapore has the best
infrastructure and logistical support. It is therefore not
surprisingly the top site for re-exportation of fish. Along
with proper packing of the shipments, with advanced materials
used for selective permeability, optimal packing can be achieved
and thus maximal profit. The official trade in Singapore is
between $80-90 million a year. In the Southeast Asia region,
the total official trade is between US$150-200 million, but
as noted earlier, the actual figures may well reach US$300-400
million. How much of this is represented by the wild-caught
fish trade is not known but is generally acknowledged to be
quite substantial. We have observed in many cases that fishes
exported which were supposedly "bred in captivity"
were actually caught from the wild.
At the moment, captive breeding of certain
species is simply not economical, with wild caught populations
far cheaper. Certain species are no longer collected from
the wild, as the captive stock has been successfully bred
and are now mass produced, thus very cheap. Examples are Trichogaster
trichopterus and Puntius tetrazona. Different colour
varieties of Trichogaster trichopterus are readily
available from the market at affordable prices. The Moss-green
variety of Puntius tetrazona had been developed by
Singaporean breeders and a variety of colour forms are available.
Deforestation is probably the main reason
why fishes and many other organisms (both faunal and floral)
are now endangered. Sustainable harvest of wild populations
is possible, if the managers and government offices have sufficient
knowledge and foresight to preempt disasters. There are certain
fish dealers who only collect a limited number of specimens
and fully acclimatise them before sale to customers overseas.
The trade and hobby should be geared towards healthy fish,
rather than high volume but low grade fish; and also towards
sustainable harvest and captive breeding. This we believe,
is good for the trade, hobbyists, and will also help the cause
of habitat and species conservation in general.
List of references.
Photos of other aquarium fishes:
The neon rasbora (left), Rasbora axelrodi
is becoming increasing popular in the trade. On the right
is the beautiful bleeding heart puffer, Carinotetraodon
spp.
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