Media Review: Important Advances in the Aquaculture of Marine Angelfish

This month’s column will
focus on two very exciting announcements in the aquaculture of
marine angelfish. These developments hold the promise of
significantly reducing the negative impact of fish collection on
wild populations of these beautiful fishes while providing a
source of aquarium specimens for those who wish to keep them.

Both breeding programs were established in Hawaii, based on
two groups of Hawaiian angelfish, organisms with special appeal
to aquarists. The collection of fishes from the wild for the
aquarium trade is a hot issue here in Hawaii, with much public
opposition in the face of verified declines in the abundance of
collected species. The state of Hawaii, especially the Kona coast
of the Big Island (Hawaii) stands third as a world source of
aquarium fishes, exceeded only by exports of live specimens from
the Philippines and Singapore.

The impact of collection is clear. The

December 2001 issue
of The Smithsonian reports, in
“Something’s Fishy,” that Brian Tissot, a
Washington State University marine ecologist, found that in
Hawaiian waters targeted by aquarium collectors, populations of
eight of the most popular species had fallen by 38 to 57 percent.
More than 400,000 reef fish are collected from Hawaii’s reefs
annually for the aquarium trade. (

Honolulu Advertiser, January 23, 2002
)

Flame Angel

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The flame angel (Centropyge
loriculus)
in these pictures is maintained by the author
in his reef tank. This angelfish is very popular with marine
aquarists, and it is the author’s hope that they will be
successfully reared in captivity, limiting the impact of
collecting wild specimens.

William Walsh, marine biologist attached to Hawaii’s
Division of Aquatic Resources states that, based on
collectors’ reports, 52% of collected fishes here are yellow
tangs, yielding an astonishing figure of 200,000 yellow tangs
taken per year. To me, this leads to the clear inference that
high mortality rates must exist at every level of the trade from
collection through the end point in the tanks of consumer
aquarists. The Smithsonian article quotes Hawaiian collector
David Dart as saying that in good weather, an average diver can
pull in 100 to 150 yellow tangs a day, and there are many
collectors here. It is no surprise therefore, that the success of
the breeding programs were seen as important enough to gain
attention in the local press.

On January 20, 2002, West Hawaii Today in an article titled
“Rare ornamental fish bred in captivity” (p.12A)
reported that the Hawaiian masked angelfish, Genicanthus
personatus
, had been bred in captivity at the Waikiki
Aquarium. The fish, a native of the Northwestern Hawaiian
Islands, is one of the most rare and sought after aquarium
specimens.

The newspaper article was based on a
Waikiki
Aquarium News
bulletin of January 18, “Waikiki Aquarium
Announces Breeding Breakthrough For One Of World’s Rarest
Fishes”.

Bruce Carlson, the Aquarium’s director stated, “The
success of this research expands the possibilities of including
one of the rarest and most sought after species to the list of
ornamental fishes commercially raised for world wide trade.
We’re thrilled with this landmark achievement in the field of
aquaculture.” Hobbyists pay as much as $5,000 for the
angelfish. Aquaculture scientists have attempted for decades
breed and to rear specimens of the more than 70 species of
angelfishes.

It is important to note that the parental fish were all
juvenile females when they were collected at Midway Island in
1993 and grew to maturity at the aquarium. Spawning began when
one of the females changed sex and became a male, which is normal
in the development of the species.

Flame Angel

The flame angel (Centropyge
loriculus)
in these pictures is maintained by the author
in his reef tank. This angelfish is very popular with marine
aquarists, and it is the author’s hope that they will be
successfully reared in captivity, limiting the impact of
collecting wild specimens.

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The larval masked angels were successfully brought through the
75 or more days to develop from hatching to metamorphosis, and
the juveniles were reported to be one-half inch miniatures of
their parents. The article states, “A breakthrough came when
aquarium biologist Karen Brittain discovered a new, living food
source to sustain the small larval angelfish.”

On January 23, 2002 the
Star-Bulletin
of Honolulu, in “Researchers hatch angelfish in
captivity” and the

Honolulu Advertiser
in “Biologists score breakthrough in
raising reef fish,” reported another major event in the
development of the aquaculture of aquarium species. On January
17, 2002, the Oceanic Institute of Oahu had

announced
that research teams led by Dr. Charles Laidley and
Dr. Robin Shields succeeded in obtaining natural spawns of the
popular and beautiful flame angelfish, Centropyge
loriculus
, and in nurturing the larvae through metamorphosis
at the hatchery, The initial group of juvenile flame angelfish is
almost three months of age and will be joined by additional
batches in 2002.

The Institute based its success on its research in food fish
aquaculture. Dr. Anthony Ostrowski, Finfish Program Manager for
the Oceanic Institute stated, “The key to this recent
success was in culturing suitable microscopic organism
(zooplankton) as prey for the angelfish larvae. Conventional
diets are too large for such tiny larvae, therefore our
researchers isolated plankton directly from the local reef
environment.”

Recently, researchers at the facility also obtained the first
recorded fertilized natural spawns of yellow tang, Zebrasoma
flavescens
, under aquaculture conditions and documented the
early developmental stages of the larvae. They have not yet
succeeded in rearing the larvae to the juvenile stage.

“The challenge now for our researchers is to convert
these early achievements into reliable technology that will allow
commercial cultivation of high-value species such as the flame
angelfish and yellow tang,” said Ostrowski. “Such
advances will bring new employment opportunities and lessen the
impact the aquarium trade has on Hawai’i’s fragile coral
reef ecosystem.”

The Honolulu Advertiser story included reports of successful
aquaculture of another aquarium species, as reported by the
Oceanic Institute. Frank Baensch, an independent researcher
working in collaboration with Dr. Malia Chow at the Hawai’i
Institute of Marine Biology, has developed techniques to culture
another Hawaiian dwarf angel, Centropyge fisheri,
Fisher’s angelfish, in captivity. The work was based on
collaboration with respect to techniques. Some of the
Fisher’s angelfish reared by Baensch will soon be on display
at the Waikiki Aquarium.

In a related development associated with the attempt to
mitigate the decline in target fish populations associated with
collection for the aquarium trade, the Hawaii state legislature
enacted bills three years ago to establish “Fish
Replenishment Areas (FRA’s)” covering one third of the
Kona coast of Hawaii, the state’s major collection region.
The sites, which are monitored, include areas protected for a
minimum of ten years that prohibit collecting, fishing, or both.
Comparing target fish populations in the recently fully
restricted areas with those closed only to aquarium collecting,
and those open to all fishing, Kona marine biologist Walsh’s
numbers are beginning to detect some positive trends. Three years
into a five-year study, he has found that the yellow tang is no
longer declining in the newly protected areas, but continues to
decline in open areas.

In his surveys, Walsh also counts the baby recruits in
protected and unprotected areas. The fact that he has yet to
detect much of a difference worries him. “Without an
increase in recruitment, the reserves won’t realize their
full potential,” he says. I will have a full report on the
recent data on the effectiveness of the FRA strategy in my next
column.

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As a final note, West Hawaii Today, on February 27, reported
that Dr. Bruce Carlson, the current director of the Waikiki
Aquarium, has announced that he will resign from the aquarium to
become the Vice President for Life Sciences at the new Georgia
aquarium, scheduled to open in 2005. Carlson pioneered public
aquarium displays of living corals and the fascinating mollusc,
Nautilus.

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 Doug Robbins

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