Whale Shark at Bida Nok
The Adventure Club are having a fantastic low season in terms of shark sightings; the Blacktip Reef Sharks are very active around Bida Nok, we see Zebra (aka leopard) Sharks at almost every trip to Gareng Heng and then yesterday the Holy Grail – the Iconic Whale Shark! (Specifically a juvenile 3 -4 meter female)
Like human fingerprints, whale sharks are individually identifiable based on their characteristic spot patterns. Using similar technology to that used by NASA to identify constellations in the sky, scientists are able to use the unique patterns around the gills & primary dorsal fin to identify the individual whale shark. The Adventure Club are happy to have contributed to these conservation efforts and have sent photos to whaleshark.org for identification purposes and population research, in addition to the DMCR Thailand. (Department of Marine and Coastal Resources.)
Whale Shark Facts
Whale Shark, Rhincodon typus
- Whale Sharks are both the largest fish, and the largest shark in the ocean, typically growing to around 10 – 12 meters, but with specimens up to 18 meters having been reported!
- They can weigh up to 15 tons.
- The “whale” part in its name is both due to its length in comparison to whales, as well as to its feeding behaviour, since both are also “filter feeders”.
- As a filter feeder , Whale sharks are one of only three known filter-feeding shark species (along with the basking shark and the megamouth shark).
- They feed almost exclusively on plankton, as well as krill, fish eggs, clouds of eggs during mass spawning of fish and corals, crab larvae, occasional jellyfish, sardines, anchovies, mackerels, small tunas, and squid
- Whale sharks have a mouth that can be 1.5 m wide, containing 300 – 350 rows of tiny teeth (a total of approx. 3,000 teeth in its entire mouth) and 10 filter pads which serve to separate food from water.
- Unlike many other sharks, whale sharks’ mouths are located at the front of the head rather than on the underside of the head. The head is wide and flat with two small eyes at the front.
- Whale sharks are grey with a white belly. Their skin is marked with a pattern of pale yellow spots and stripes which are unique to each individual, allow for identification.
- The whale shark inhabits all tropical and warm-temperate seas. This fish is primarily pelagic and are non-predatory.
- Whale sharks are thought to live between 60-100 years.
- They cannot reproduce until they reach 25 – 30 years old.
- Whale Sharks are OvoViviparous meaning the embryos develop inside egg cases, but they hatch inside the uterus, so give birth to live young.
- Whale sharks are believed to have the most shark pups in a single litter. A female caught in 1995 contained about 300 embryos, the largest litter size reported for any shark species. However they will then produce a litter of only between 2-12 live pups at a time.
- Neither mating nor pupping of whale sharks has been observed.
- According to the IUCN, the Indo-Pacific population of the whale shark is thought to have reduced 63 percent over the past 75 years. Populations are continuing to decrease and as such whale sharks are classified as endangered.
- Impacts of fisheries, bycatch losses, and vessel strikes, combined with its long life span and late maturation combine to threaten this docile species.
- Demand for their meat, fins and oil remains a threat, particularly by unregulated fisheries.
- A single whale shark pectoral fin can sell for up to $20,000, making it one of the most sought after of all sharks in the fin trade
- In Thailand the Whale Shark is listed as a protected species under wildlife conservation law,as well as being included on a fishery prohibition ban list of the Fisheries Department.