There’s a ‘gentle giant’ on the 100-peso bill, although you may not have noticed it.

Billed as the biggest fish in the world, the whale shark or ‘butanding’ is known to grow up to 9 meters in length. Those who have traveled to Donsol in Sorsogon in southeastern Luzon know that they can interact directly with these fish.

While in the past, local fishers tended to kill this slow-moving fish, eco-tourism has helped preserve their population. First identified in 1828 in Africa, this distinctly yellow-marked shark has a flattened head and a round, blunt snout―unlike most sharks, which have their mouths under the head. It also has a spiracle or vestigial gill slit behind its eye for breathing when it rests on the sea floor.

The mouth has two barbell-like protrusions from its nostrils that give it a friendly, almost comical look. Overall, the butanding tends to be gray or brown with a white belly, and has vertical and horizontal stripes. These markings are unique to each individual of the species and can help identify them.

Its skin can reach 10 centimeters in thickness, and females tend to be bigger than the males. It also has two dorsal fins towards the rear of its body and a two-lobed tail.

A previous article in Animal Scene stated, “The largest recorded individual whale shark was almost 13 meters long and weighed more than 21.5 metric tons. Not actually a whale and more of a shark, the whale shark is a filter feeder, like a whale, filtering tons of plankton, krill, small fish, and other tiny ocean tidbits through its mouth and gills.”

This accounts for their large mouths (with 3,000 teeth) and five pairs of gills. Only three shark species are known to filter feed, with the other two being the basking shark (incidentally the second biggest fish in the world) and the megamouth shark.

Unlike other sharks, the butanding need not swim forward to feed; it can stay in a vertical position and simply bob up and down, swallowing water and filtering it for food. When it shuts its mouth, water leaves through its gills and whatever isn’t forced out through there is what the butanding feeds on.

Unlike most sharks, which elicit a shudder of fear, the butanding is harmless to humans. Donsol is a seasonal feeding site for a large school of them, and you can go snorkeling with them; just avoid photos in which you harm or hurt them! Also, swimmers and divers are advised to keep clear of its large tail fin, which can accidentally hit and injure them.

Tip: younger butandings tend to be more playful! It’s easy to stay abreast of butandings, which reach a top speed of, at most, 5 kilometers per hour; they move their entire bodies from side to side to swim.

While their mating habits have not been observed, whale sharks are known to be oviviparous (eggs hatch and develop in the uterus of the female). They give birth to live offspring about 40-60 centimeters long. While the female can carry up to 300 embryos, only about 10% of these are expected to survive to birth, and these take 30 years to reach maturity. Once born, the mother leaves her offspring, making them vulnerable to predators.

There are long intervals between pregnancies, though they are expected to live up to 150 years in the wild if left alone. Given that the Philippines has the highest concentration in the world of whale sharks, when in 1998, it banned all fishing, selling, importing, and exporting of whale sharks for commercial purposes, this was a good move for the preservation of the species. India (2001) and Taiwan (2007) followed suit.

What a lot of people don’t know is that the whale shark is an important part of the marine ecosystem, linked to the survival of creatures like crab and other fish, and even coral reefs. The International Union for Conservation of Nature considers the butanding to be a vulnerable species, especially crucial because there are no population records for it.

It is listed on the CMS Memorandum of Understanding on the Conservation of Migratory Sharks, along with 6 other shark species; it is also on Appendix II of the 2003 Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) that regulates the international trade of live specimens and their parts. (Compiled by CFB.)


Scientific Name: Whale shark (Rhincodon typus)

Habitat: Tropical, warm-temperate waters; they seem to prefer the bottom of the sea

Habits: Highly migratory

Depth Can dive to 1,200 meters Size Anywhere from 4.5 to 14 meters in length

Average weight: Approximately 750 to 1,500 kilograms

Diet Plankton and krill

Also known as Vietnam: Ca Ong(literally means “Sir Fish)Mexico and throughout

Latin America: Pez dama, or domino(because for its patterns of spots)

Africa: Papa Shillingi in Kenya (in the belief that God threwshilling coins on it, hence its spots)Indonesia (Java): geger lintang, meaning, “stars in the back”

Found at Seasonal feeding areas, which include (in addition to Donsolin Sorsogon):

• Southern and eastern parts of South Africa;

• Saint Helena Island in the South Atlantic Ocean;

• Gulf of Tadjoura in Djibouti, Gladden Spit in Belize;

• Ningaloo Reef in Western Australia;

• Lakshadweep, Gulf of Kutch, and Saurashtra coast of Gujarat in India;

• Útila in Honduras;

• Southern Leyte, Pasacao, and Batangas in the Philippines;

• Off Isla Mujeres and Isla Holbox in Yucatan and Bahía de los Ángeles in Baja, California, and México;

• Ujung Kulon National Park and Nabire National Park in Indonesia;

• Nosy Be in Madagascar;

• Off Tofo Reef near Inhambane in Mozambique;

• Tanzanian islands of Mafia, Pemba, Zanzibar;

• Dimaniyat Islands in the Gulf of Oman; and

• Al Hallaniyat islands in the Arabian Sea Did you know? Butandings can process over 6,000 liters of water per hour when they feed.

This story appeared in Animal Scene’s March 2015 issue.