Philippine seahorse: Out of danger

THE PHILIPPINE seahorse

(Hippocampus spp.), reported last

year to be on the brink of extinction, is

out of danger.

And the fishermen--the very people who threaten its

existence--may yet be the same people who will play a crucial

role in assuring and enhancing its production and survival in

the wild.

This will be accomplished by seeding

known seahorse habitats with

seedlings and mature seahorses

produced through simple techniques

developed by researchers at the

Mindanao State University in Naawan,

Misamis Oriental.

'The technology we have developed

is very simple and the cost will soon

be within the reach of ordinary

fisherman,' said Emilio Tubio, the

research team leader.

'Instead of continuously harvesting

the animal from the wild and

eventually depleting its natural stock, the fishermen may soon

raise it in their own backyard, using locally available materials,'

Tubio said during a research-in-house review held recently.

Dr. Marcelino Tumanda Jr., dean of research at the MSU

Institute of Fisheries Research and Development, announced in

the same forum that the university will teach the fishermen how

to raise and make money from seahorses.

But they must 'make a covenant with us that they will release to

seahorse habitats a certain percentage of their production (to)

ensure the survival of the species and provide them with sturdy

broodstock and breeders from the wild,' Tumanda said.

Seahorse habitats include seagrass beds, coral reefs and

mangrove estuaries.

Medicinal

The seahorse is exploited worldwide for its reputed medicinal

value. According to traditional Chinese medicine, it is known to

cure various ailments, such as asthma, arteriosclerosis, skin

diseases, goiter and lymph disorders.

It is also reported to be a potent aphrodisiac that has been used

by the Chinese and other Orientals, centuries before the

controversial Viagra.

It is also collected for the aquarium and curio trade.

The exploitation of seahorses for international trade is very

serious. In 1994, the Chinese reportedly consumed six million

seahorses and the Taiwanese, three million.

Dried seahorses cost $250-450 per kilo and live ones, for as high

as $1,500 per kilo. Thus, fishermen in the Philippines and

elsewhere go berserk in harvesting the animal, even to the edge

of extinction.

Commercial scale

The study of the MSU-Naawan aims to produce seahorses on a

commercial scale under controlled conditions, similar to how

sugpo (tiger shrimp) production was revolutionized in the late

1960s.

In the Naawan experiments, seahorse breeders weighing 9-16

grams each and with body lengths of 8-10 inches, were collected

from the wild and stocked in five pairs in 45-liter aquariums. The

tanks were mildly aerated and well-lit.

The breeders were fed with artemia. The tanks were cleaned

daily and water was replaced once a week.

One unique characteristic of seahorses is that the males bear

pregnancy. The males, nonetheless, actively initiate the

courtship.

'Seahorses are gentle, monogamous and sexually faithful

creatures,' says Ruby Gonzales, a member of the research team.

'It is reported that in the wild, pairs do not divorce and a pair

bond only terminates when one partner disappears or dies.'

Incubation lasts 12 days. A day after the release of the

hatchlings from the male pouch, courtship starts again. The

hatchlings number from 430 to 484.

Accidents in the transfer of eggs during copulation would

cause the eggs to drop to the bottom of the tanks. This

contributes greatly to very low production.

'Incomplete' or aborted copulation was attributed to the rather

low water column in the tanks. The couples, at times, reach the

surface of the water and are forced to separate without

completing copulation.

Larval rearing

The larvae are separated from their parents and reared in

separate tanks. They are fed live copepods, a zooplankton that

is dominant in most coastal waters, immediately upon their

extrusion from the male pouch.

Feeding is unlimited inasmuch as copepods are abundant in

nearby coastal waters. Fed alive, copepods do not pollute the

culture medium.

After 10 days of culture, the experiment showed that there was

no significant weight difference among the young seahorses

which were fed with artemia, copepods, or their combination.

This implies that one can do away with the expensive artemia as

feed.

After 30 days, however, the seahorses start to show preference

for the combination of copepods and young and adult artemia.

The primary problem of seahorse production at the

MSU-Naawan is the infestation of breeders with protozoans.

Heavy infestation causes body wounds that usually result in

bacterial and fungal infection. When this occurs, the seahorse

loses its appetite and eventually dies.

The researchers, however, solved this problem through 'water

cure' treatment. A certain volume of freshwater is added to the

tanks to dilute water salinity up to a certain point that kills all

protozoans without harming the seahorses.

Aquaculture

Commercial production of seahorses in confinement has very

promising prospects. Breeders are easily available in the wild

and can be produced in captivity.

The seahorse has a short life cycle and can be raised and

harvested in four months. It can be cultured in tanks made of

wood, canvas or other cheap materials.

Demand for seahorses is very high in the local and international

markets and the price they command simply dazzles the mind.

At the moment, the Naawan researchers are concerned with

coming up with cheaper feed substitute for artemia, an imported

product (also the main feed for shrimp and prawn larvae).

'We are experimenting on various possible feeds for seahorses.

We learned that the animals feed on mysid, a tiny shrimp-like

malacostracan crustacean,' Tubio said.

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