TIM eMagazine Vol.4 Issue 2
Super Samaral (Siganus
guttatus x S. Vermiculatus)
weighing 486.0 g
Credit: Dr. Westly Rosario / BFAR
Siganus Vermiculatus,
breeder weighing 733.0 g
Credit: Dr. Westly Rosario / BFAR
Their experimental hatchery is now achieving very reasonable survival
rates of 5% from larvae to fry sizes in 45 days. The fry is stocked in nursery
ponds and reach fingerling size in about 90 days. Fingerlings can then be
further cultured in brackish-water ponds, pens or floating sea cages. In
lower densities, the fish can be fed with filamentous algae, seaweed and
sea grass which grow luxuriously in brackish-water ponds. However for
large culture volumes, a local plant-based pellet feed that ensures good
Siganus guttatus breeder
weighing 533.0 g
Credit: Dr. Westly Rosario / BFAR growth and survival rates, has already released by local feed producer
Tateh Feeds. Fish can be harvested at 250 grams within five or six months
of culture from fingerling size.
Rabbitfish are also ideal candidates for polyculture systems as they
are non-aggressive and feed mostly on filamentous algae and other
in the province of Dagupan is one of the scientists behind the successful
vegetation. In the Philippines they are already co-cultured with both
culture of Milkfish. In recent years however, he and his team also saw the
Milkfish and shrimp. They have also been experimentally co-cultured with
need to diversify the country’s aquaculture sector. For the past years, they
grouper, with small numbers of Rabbitfish added to grouper cages to keep
have been putting a lot of effort in the culture of Rabbitfish. Actually, as
the floating nets relatively free of algae and seaweeds.
he explains, it was his father who first experimented with and saw the
To further improve growth and survival rates, Dr. Westly explains how
potential of these fish.
he came up with the idea of developing a hybrid between the Golden
Rabbitfish (Siganus spp.) are medium-sized herbivorous fish native
Rabbitfish and the Maze Rabbitfish. This took some trial and error as S.
to the Indo-Pacific region, thriving in coastal areas. Some species prefer
guttatus spawns during the first quarter of the lunar calendar, while S.
brackish-water mangrove habitats while others live in and around coral
vermiculatus spawns during the last quarter (as the team later found out,
reefs. Locally known as Danggit and Samaral, these fish are very popular
the hybrids will only spawn during a new moon). These findings on lunar
and sought-after food fish. As Dr. Westly explains, “the Philippines is
cycles will enable Rabbitfish hatcheries to maximize production year-
the top producer of wild-caught and cultured Rabbitfish with annual
round. These hybrids should grow better than the parent species because
landings of around 30.000 metric tons (MT). The demand for export within of hybrid vigor and show stronger disease resistance while fetching the
Southeast Asia and other markets like Hawaii is very high. However, few
same price in fresh fish markets. However, some questions remain on
Filipinos are raising Rabbitfish due to the low supply of fingerlings and
the potential of these hybrids escaping and reproducing in the wild. It is
un-disseminated technology. Their popularity as food fish is leading to the important to never let this happen.
decline of their numbers in the wild.”
Despite the strong foundations laid down by Dr. Westly and his team,
About 10 years ago Dr. Westly and his team started working to close
the Philippines was still producing a paltry 303 tons of Rabbitfish through
the lifecycle of these fish in captivity. Eight years ago, they successfully
aquaculture in 2018, however this is almost 90% of global production, plus
cultured two of the most commercially-interesting candidates, the
the figure is up 56% compared to the 194 tons produced in the country in
Golden Rabbitfish (Siganus guttatus) and the Maze Rabbitfish (Siganus
2017.
vermiculatus), for the first time. Both species are popular food fish, growing
It cannot be denied that the culture of lower-trophic marine herbivores
to about 50 centimeters with a maximum weight of one kilogram for the
like Rabbitfish has enormous potential to feed the world’s steadily-
first and two kilograms for the latter. Fresh, they fetch around PHP 325 per
ballooning population, while simultaneously reducing the environmental
kilogram farm gate (USD 6.20), and PHP 380 per kilogram retail (USD 7.20), footprint of the food we produce. This is a path more aquaculturists and
which in comparison is almost double the price of Milkfish.
investors should explore.
https://thefishsite.com/
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