One of the advantages of writing a blog is being able to occasionally plug your own work, or in this case what is primarily the work of a friend and colleague. This amazing story begins on the morning of March 7, 2009 in Donsol, Philippines. Elson Aca, at that time the Donsol Whale Shark Research Coordinator for WWF, received a call from Gilbert (Embet) Guadamor, one of the BIOs, the Butanding Interaction Officers who manage whale shark ecotourism encounters. Embet said that a local fisherman had caught a whale shark in his net off a nearby beach. (Although whale sharks are protected in the Philippines, and are not actively fished, they are sometimes caught accidentally in nets.)

Elson, Embet, and local officials set out on a rescue mission, expecting to find one of the 6-8 meter whale sharks common near Donsol. Arriving at the beach, however, they did not see any evidence of a whale shark. Eventually the group noticed a small stick stuck into the sand, with a piece of string attached and trailing into the water. Following the string revealed something incredible - a tiny whale shark tethered by the string tied around its tail. Instead of the expected huge whale shark, the group was confronted with what would turn out to be the smallest free-living whale shark ever reported - this likely newborn animal measured only 46 cm from mouth to tail tip. The small shark appeared unharmed, swimming for all it was worth against its restraint.

We know so little about the embryonic development, birth and early life of whale sharks. Finding a newborn whale shark is an extremely rare event; prior to this date, only 12 neonatal animals had been described in the scientific literature. This rarity is even more surprising if you know how whale sharks develop within the female. The single pregnant female whale shark that has been studied carried more than 300 embryos in her uterus! If this number of offspring is typical, where are all the baby whale sharks? Regular sightings of whale sharks don’t begin until the animals are about 2.5 meters in length, and perhaps one year of age. The habitat used by whale sharks during their first year of life is entirely unknown, and one of the most fascinating questions about these mysterious animals.

What of our small Donsol shark? The pup was quickly measured and photographed, and within 3 hours of WWF notification was on a boat headed back out to sea. Elson and crew released the pup in deep water away from fishing areas, where it swam quickly away from the boat and began to dive. As amazing as this story is, three weeks later a second neonatal whale shark was found near Donsol. This pup was 63 cm in length, nearly 40% larger than the March 7 animal; it was also documented and released. Whale sharks are believed to grow very quickly during their first few months, so the relative sizes and timing of these two pups suggests that they may have been siblings from a single litter born in the area.

You can read the article describing these two pups, and a slightly older (even more rare) juvenile, here:

http://www.uic.edu/labs/schmidtlab/pdf/Aca%20&%20Schmidt%202011%20Asia%20Life%20Sciences.pdf

A great video of Elson and the shark can be found here:

http://www.youtube.com/watch?v=QvAyJbeOem0

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