Endemic Surigao oyster a high-priced delicacy

MANILA, Philippines – It is not surprising to know that the country has an exceptionally high rate of endemism or the prevalence of particular species exclusively within the country’s geographic boundaries.

Given the abundance of its coral reef life, the Philippines is regarded by international marine scientists as the “Center of Marine Biodiversity” in the world, surpassing the Great Barrier Reef of Australia.

One endemic species recently discovered is a marine bivalve mollusk, locally known as tikod amo. It is an oyster species which can only be found in the coastal municipalities of Barobo, Lianga Bay in Surigao del Sur.

The name originated from the Kamayo, language of people living in the central eastern coast of Mindanao, which was derived from the external appearance of the oyster which means ‘ankle of an ape’ (adductor muscle). Physically, the meat of tikod amo is aesthetically appealing with its internal parts having multiple colors.

“This species seems to be unknown in the international species nomenclature database. We found no information that describes its biological features, so we assumed tikod amo is a new species,” said Gemma A. Asufre, researcher from the Surigao del Sur State University (SDSSU).

Based on a  study conducted by UP-Los Baños, “there was a five percent difference of the DNA of tikod amo from the DNA of spondylus squamosos.’’ Although the difference will still have to be verified, the researchers are certain that tikod amo can be “considered as a new species of Spondylus (group of marine bivalve mollusk).

The study showed that tikod amo oysters were observed attaching into rocks, hard corals, logs, shell substrates, bamboo poles, and old tires. Others were found in hard surface bottoms.

These observations served as bases for the researchers to prove that this endemic oyster has higher potential for culture which addresses its declining population in the coastal areas of Barobo.

A seafood delicacy, tikod amo is an instant hit, not only among the locals, but also to those who have heard about it and have tried its unique and delicious taste.

Harvesting tikod amo has also become a good source of income among the marginalized fishers in the coastal areas of Surigao del Sur. Given its high demand, the price of tikod amo is higher than the price of any ordinary oyster meat available in the market. Its current price in the local market is about P400 per kilo for the unshelled meat. With such demand, production cannot adequately supply the local hotels and restaurants.

Among the foreigners who came to know about this rare oyster species, tikod amo has become a hit amid curiosity about its distinct taste.

With the increasing demand for tikod amo and the constant harvest, the natural stock of this oyster in the wild is now being threatened.

Also, the practice among gatherers of collecting spat (baby oysters) from the wilds is not sustainable and it poses a threat, not only to the diversity of oyster species in the area, but also to the hard coral substrates where these species naturally dwell.

As a result, the oyster catch has declined by 40 to 60 percent between 2006 and 2008.

The SDSSU conducted a study to look into the specific methods and systems to address the declining population of oysters.

According to the study, integrating oysters in a polyculture system could be applied on 146 hectares of fishpens in the mariculture zone.

Polyculture is the practice of raising more than one species of aquatic organism in the same pond. The principle behind this approach is that fish production can be maximized by raising a combination of species.

Compared with monoculture system of fish production, the possibilities of increasing fish yield per unit area through polyculture is considerably higher and more profitable. Combining different species in a polyculture system also effectively improves the pond environment.