History's smallest whale shark rescued in Sorsogon (2)

The team freed the shark from the rope that was tied around its tail. After checking to see that the animal was unhurt, documenting the discovery, and measuring the shark, they transferred it into a large, water-filled plastic bag to allow it to swim freely while preparing for its release. Less than three hours after the report first reached Donsol, the response team was back on their banca, shark safely in hand. They took the shark out to deeper water, where it was less likely to get entangled in a fish net, and there, they set it free.

In spite of all the research that is being done worldwide on whale sharks, to this date no one knows where they breed or give birth. The Pilar 'pup' was so small, it was probably born here and could have been what biologists call a neo-nate. Not only is this animal the smallest live whale shark on record ever to be captured and released here in the Philippines (and arguably, anywhere in the world), it is also the first indication that the Philippines, at the apex of the Coral Triangle, is probably one of the places on the planet where these giants of the sea are born.

For many years, scientists thought that Donsol was merely one of many 'gas stations' along the global network of marine highways where whale sharks cruised. This new discovery is the first ever indication that this coastline may actually be a 'birthing site'. - Jose Ma. Lorenzo Tan, WWF-Philippines vice-chairman and CEO

The World’s Largest Living Fish is a Shark

The whale shark, locally known as “ butanding “, is the world’s largest fish. This gentle giant is known to grow to great lengths of up to 18 meters and can weigh up to 34 tonnes. As a highly migratory species, whale sharks are distributed worldwide in warm and temperate seas of the Atlantic, Pacific and Indian Oceans. They can migrate long distances through international waters to favored coastal areas in a few months of the year when the plankton they feed on is abundant.

Food is an important factor for the growth, migration and abundance of whale sharks in time and space. Its presence is highly associated with blooms of planktonic organism and changes in water temperature. Unlike other species of sharks, the whale shark can neither bite nor chew. Its thousand of teeth are so tiny that it can only eat small shrimps, fish and plankton by using its modified gift rakers as suction filter.

Whale sharks are slow growing, maturing sexually only after so many years and with long interval between pregnancies. Female have been found to produce as many as 300 embryos in her uterus, although it is thought that less than 10% of the young survive to adulthood. Upon giving birth, the mother sharks leave her young to fend for themselves. In effect, the species have low reproductive potential and low capacity for population increase. These make the species highly vulnerable to exploitation.

The ecological role of whale sharks is not yet fully understood but the links of these giants with other processes within an ecosystem cannot be underestimated. Whale sharks are related to important ecological processes such as crab, fish and coral spawning. As possible indicators of plankton-rich patches, whale sharks may be using baitfish to locate their prey.