"You
and I know that captive breeding is the ultimate
answer to current
collection
practices that are endangering the survival of too
many species".
-Terry
Siegel
What
a great statement to open a new column on fish breeding.
This thought led me right into the many ways to
prove his statement, or better yet -and more constructively
- to start a discussion on why we should breed fish
in our home aquariums.
I
begin with a short overview of the reasons why collecting
fish for the home aquarium may have serious impacts
on the future of these species in the wild and why
we want to breed fish in our homes. Welcome to my
view from inside "The Breeders Net".
So
how bad off are we?
All
of us understand that the fish we have in our captive
care originated in one of the many oceans of the
world. I believe we all know that someone has collected
these fish and transported them across continents
and countries to get to our LFS (local fish store).
What I don’t think we understand is the ramifications
of taking these fish out of the wild. Sure you’re
saying there are lots of my "X" kinds
of fish, and taking my fish out of the wild is no
big deal. Accompanying that idea you’re thinking
"well this is a fish with a huge ocean to swim
in and the range where it can be found is enormous.
Why would removing my fish be that important?"
A clutch of
clownfish eggs nestled under the parents'
host anemone
A male P.
flavivertex cradles an egg mass inside
his adopted PVC tube
In reality is it important,
coral reefs are the most biologically diverse shallow
water marine environments, and they support hundred
of thousands of animals and plants 1. With
this enormous diversity comes fragility. As of Feb
2002, 58% of the world’s reefs have been reported
to be threatened by human activities 2.
Agriculture, deforestation, and development are introducing
large quantities of sediments, nutrients, and pollutants
into coastal waters. With this impact comes degradation
of productive reef zones. Coral reefs are heavily
fished 3. In regions between the Pacific
and Indian Ocean, fishing with dynamite and poisons
has devastated reef habitats 4. In a survey
by Roberts et al of 1700 fish species, 26.5% had restricted
territorial ranges and were considered threatened
by over collection and devastation of their reef environments
5. That’s 450 species of fish which
we could potentially see in the pet shops.
Conversely,
it is widely believed that marine fish populations
are some of the most resilient species -- as they
have wide geographical distribution. Following this
erroneous assumption, over collection in one part
of the ocean should not impact populations found in
another area. Essentially moving to a new spot would
ensure plentiful fish. Again, data suggests this is
not true. A study by Bryant et al 2 examined
the genetic diversity of coral reef fish and found
that <28.7% had wide geographic ranges. This suggests
that restricted range fish were more prevalent in
reef environments, and that wide spread damage to
this population could lead to waves of extinction.
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sponsor of this column
So just how many
fish are taken each month for the hobby? This question is
a very difficult one to answer, mainly because accurate censuses
of fish are not taken. Collectors harvest as many fish as
they can to fill orders. Collectors need to account for shipping
losses to make the required quotas and this is often to the
detriment of the fish. As an example, in a report by Allen
6, he reported over 5000 banggai cardinalfish at
a collection station readied to ship to distribution stations
throughout the world. This was a monthly collection statistic,
suggesting that 60,000 of these fish are collected yearly.
This is a quantity of fish which is staggering to comprehend.
Can the wild population of fish support this volume of collection?
Only an accurate census will determine this. This is one of
the many reasons why we should consider breeding fish at home
and not subjecting the reefs to future potential devastation.
A proud dad.
A male banggai cardinalfish (Pterapogon
Kauderni) and recently released fry.
Photo courtesy of Brian Lanka http://members.aol.com/petpatrol1/
So
how are we doing?
Well,
that all depends on who you talk to: aquaculture
of fish is not new, the Romans tended beds of oysters
and medieval monasteries had ponds in which they
grew fish to eat. However, commercial production
of fish is still in its infancy. A few food fish
are grown in commercial numbers, but reef fish are
not. Commercial firms interested in producing reef
fishes must deal with a balancing problem. They
must find a hardy, resilient, fish species that
has an established appeal, and is omnivorous so
that food won’t be problematic. The fish species
must have defined breeding habits, with available
fry foods, and the breeder must be able to get brood
stock to ensure genetic variability. This all gets
weighed against food costs, growth rates, the ability
to control reproduction, adequate survival of young,
and market value. If, after all this balancing,
the fish is profitable, all the better. Commercial
breeding facilities have focused on high fecundity
fish that are hardy, readily accept available fry
foods, and have mass appeal. However, many of the
fish in our reef tanks do not fall into any of these
categories. At the end of this column I will present
a list of species that are currently bred or under
investigation for possible commercial breeding.
This way you can see which way our hobby is heading.
With
this in mind, I’ve created this column.
Over the next few
months we will discuss current topics in home breeding of
marine fish, and we’ll focus on a few fish which have
been bred with success and use them as examples for future
endeavors. Additionally, I’ll try to remove the mystery
involved in raising fry, describing simplified techniques
and tips on how to bypass the common stumbling blocks. Some
examples are: problems associated with pairing of the parental
fish, and more often the problems associated with raising
those pesky minute fry to juvenile stages where they will
actually eat food we can supply with ease
Breeding
fish at home does appear intimidating, and in fact
only recently did the techniques/resources required
to raise fish become available to the hobbyist.
(Martin Moe’s been doing it since the 70’s
using ocean water with live plankton. It’s
just easier now with new products) Commercial firms
and universities that have financial investments
in equipment, brood stock, and larval foods to produce
a few offspring designed these techniques and resources
(particularly foods). Now, by making a few phone
calls and ordering commercially prepared planktonic
foods (such as phytoplanktons and rotifers) many
home aquarists are successfully breeding certain
fish on a small scale.
If
we entertain the idea of actually breeding the fish
we desire and keep in our own aquarium, not only
can we eliminate future capture of these fish, but
the surplus can go back to the LFS -- or better
yet, be bartered with our peers.
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sponsor of this column
Fish commonly
bred in Aquaculture
Common Name
- Species
False clownfish - Amphiprion Ocellaris Orange clown - A.
sandaracinos
Red Saddleback Clown - A. ephippium
Clarki Clownfish - A .clarkii Cinnamon clownfish
- A. melanopus
Tomato Clown - A. frenatus
Pink Clown - A. periderian Clown Clownfish -
A. percula Skunk Clownfish -
A. akallopsis
Maroon Clown - Premnas bimaculatus Neon Dottyback - Pseudochromis
aldabrensis Sunrise Dottyback
- P. flavivertex Orchid dottyback -
P.fridmani
Springeri dottyback - P. springeri
Yellow dottyback - P. olivaceous Neon Goby - Gobiosomas
oceanops
Red Head Goby - G. puncticulatus Goldline Goby - G.
Randallii Genie Goby - Gobiodon
genie
Green Banded Goby - G. multifaciatum
Yellow Clown Goby - G. okinawae
Citron Goby - G. citrinus
Marine comet (marine betta) - Calloplesiops altivelis Royal grammas - Grammas
loreto Banggai cardinalfish
- Pteragon kauderni
Mustangs Seahorse -
Hippocampus sp.
Jeuvenile banggai cardinals
seeking shelter amongst the spines of a sea urchin.
Future topics
of "The Breeder’s Net" include: Which fish?
-Commonly bred fish in the home aquarium. Clowns, dottybacks,
cardinals, gobies, seahorses Sexing of fish
- How can we ensure we get the correct ratio of sexes or just
the right sexes of fish so we can breed them. The baby nursery
- Setting up an appropriate tank for fry hatching, and raising Babies’ first
foods - Size appropriate and nutritional complete
food for hungry offspring. Alternative foods
- Can we bypass some previously required foods? Combating disease
in the eggs, offspring, and parents Grow-out
tanks - We’ll get into what it takes to get
the fry from free-swimming planktonic larvae to sizeable little
fish capable of eating prepared foods.
Enjoy your aquarium
and we’ll peer thru "the net" again next month.
References
Aquarium
Fish, Freshwater
and Marine Aquarium, and Tropical Fish Hobbyist,
Publications:
Frank H. Hoff’s
Plankton Culture Manual (Aqua Culture Supply, 1999).
For specific fish, read Joyce D. Wilkerson’s Clownfishes
(Microcosm Limited, 1998); Martin A. Moe Jr.’s Breeding
the Orchid Dottyback, Pseudochromis Fridmani: An Aquarist's
Journal (Green Turtle Publications, 1997); Sara A. Lourie,
Amanda C. J. Vincent, and Heather J. Hall’s Seahorses:
An Identification Guide to the World's Species and Their Conservation
(Project Seahorse, 1999).
1)- M. L. Reaka-Kudla,
in Biodiversity II, M. L. Reaka-Kudla, D. E. Wilson,
E. O. Wilson, Eds. (Joseph Henry Press, Washington, DC, 1997),
pp. 83-108. C. Birkeland, Ed., Life and Death of Coral
Reefs (Chapman and Hall, New York, 1997).
2)- D. Bryant,
L. Burke, J. McManus, M. Spalding, Reefs at Risk: A Map-Based
Indicator of Potential Threats to the World's Coral Reefs
(World Resources Institute, Washington, DC; International
Center for Living Aquatic Resource Management, Manila; and
United Nations Environment Programme-World Conservation Monitoring
Centre, Cambridge, 1998).
3)- N. V. C.
Polunin, C. M. Roberts, Eds., Reef Fisheries (Chapman
and Hall, London, 1996).
4)- R. N. Ginsburg,
Ed., Proceedings of the Colloquium on Global Aspects of
Coral Reefs: Health, Hazards and History, 1993
(University of Miami, Miami, FL, 1994).
5)- T. Goreau,
T. McClanahan, R. Hayes, A. Strong, Conserv. Biol.
14, 5 (2000).
6)-G.Allen.,
Threatened fish of the World:Pterapogon Kauderni
., J Maquaculture 7(2):22-23., (1999).
