Errol Abada Gatumbato

The Tawilis and other endemic species of the Philippines

BY: ERROL ABADA GATUMBATO

The Philippines is globally known for its numerous endemic species. These flora and fauna are scattered throughout the different islands of the archipelago, but there are also species restricted only to a particular island. Given the geological formation of the country, some endemic species are being shared between islands.  This is particularly true in the West Visayas Bio-Geographic Zone where the islands comprising it, Cebu, Negros, Panay and Masbate, have similar species composition, although there are also island endemic in these areas. The famous species shared by these islands are the Philippines or Visayan Spotted Deer and Visayan warty pig – the two critically endangered mammals reportedly extinct in the wild in Cebu.

The Tawilis of Taal Lake

One interesting scientific development was the recent announcement of the National Fisheries Research and Development Institute that the Tawilis (Sardinella tawilis) is similar to Sardinella hualienses, a fish inhabiting in marine waters in the municipality of Appari in Cagayan province. Such finding was based on the morphological and genetic assessment of these two species. Tawilis was earlier known as a freshwater sardine available only in Taal Lake in Batangas province and nowhere else in the world. The investigators, led by Dr. Mudjekeewis Santos, believe these formerly known two different species are actually one and the same, according to the report posted online by the People’s Television Network, Inc. However, Santos was also quoted saying, “This matter is still open to scientific debate”.

This recent finding is not actually new, because there were also instances in the past when one species, thought to be a different one, was declared synonymous to another species. For instance, the Rafflesia banaoana from Kalinga province, described by Botanist Pastor Malabrigo as a separate species, was refuted by the group of Botanist Julie Barcelona as the same species with that of Rafflesia leonardi, a species discovered in the adjacent Cagayan province. Malabrigo, however, is maintaining the species he discovered in Kalinga, specifically in Balbalasang-Balbalan National Park, is a different kind of Rafflesia.

Another similarity of species also involves another species of Rafflesia.  The Rafflesia speciosa, which was first recorded and described in Antique by Barcelona, was also later recorded in Mount Kanla-on Natural Park in Negros by Malabrigo.  Similarity of species composition between Negros and Panay is due to the fact that they are one landmass many years ago.  The Negros bleeding heart pigeon was thought to be an endemic species of Negros until it was discovered in Panay in 1990’s. Similarly, the Dobsonia chapmani, also known as the Negros naked-backed fruit bat, was considered as an extinct endemic species of Negros, until it was recorded in Cebu by the group of Biologist Lisa Paguntalan. However, this fruit bat was rediscovered in southern Negros Occidental by the group of Dr. Ely Alcala.

It is quite unfortunate though that most of our endemic species are already declared as threatened species by the IUCN-World Conservation Union and the Department of Environment and Natural Resources, meaning their population in the wild is getting limited, and may face extinction if no proper protection measures are instituted. Even Tawilis is similarly threatened, because its production declines through the years.  The commercial value of this sardine is a constraint in declaring it as a threatened and protected species. Habitat destruction and over exploitation of endemic species are two major reasons why many species are listed as threatened species. Many of our endemic flora and fauna are forest dependent and the remaining natural forest in the country is already limited.

November 13, 2011 - Posted by | Biodiversity Conservation, Forest Ecosystem, Fresh Water Ecosystems, Species Conservation

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