whale shark
Thursday Trivia: Whale Shark
The whale shark is the largest fish in the world and can fit a human inside its mouth. But don’t be afraid: this huge fish eats only plankton and small fish, which it gathers by pumping water over its gills.
The whale shark is one of three sharks that filter feeds, and the only one that does so actively rather than relying on simply swimming forward with its mouth open. Despite this, the whale shark has about 300 very small teeth, the purpose of which is unknown.
In addition to being the largest species of fish on the planet, whale sharks also have the thickest skin of any animal – about four inches thick. This skin is decorated with a pattern of yellowish white dots that is unique to each shark.
Whale sharks are usually solitary, but they can feed in groups. One particularly striking example of this behavior occurs around April off Australia, when immature males gather to feast on particularly plentiful plankton. Throughout their travels, whale sharks often cross entire oceans.
Whale sharks are considered vulnerable. One of the most important threats they face is shark finning – although their fins are not very popular to eat, because they are so large, they are highly prized for displays. In 1999, just one whale shark fin sold for around £11,000. Other threats include hunting for liver oil and meat and being caught accidentally as bycatch. It’s not all bad news, though! Some areas are protecting whale sharks in order to foster ecotourism.
Oceana’s shark campaign focuses on reducing shark bycatch, establishing shark finning bans, and implementing species-specific shark management.
You can learn more about whale sharks from Oceana’s marine wildlife encyclopedia, watch Oceana spokesperson January Jones swim with the gentle giants and take action to protect them.
On The Hunt For Elusive Whale Sharks
Emily went up in a spotter plane last weekend to look for whale sharks, while senior campaign communications manager Dustin Cranor was on the Latitude waiting for word of the sharks' location so the scientists on board could follow them in order to tag the animals. Unfortunately, the sharks proved elusive. Here's Dustin's report:
The whale sharks in the Gulf of Mexico spent the weekend hiding from the Oceana Latitude.
The crew spent two days searching for these sharks off the coast of southeastern Louisiana. Our hope was to tag some of them so that we could monitor their movements and contribute to scientists' understanding of the effects of the Deepwater Horizon disaster on their survival. Whale sharks were observed swimming in surface oil near the gushing wellhead earlier this year.
The two spotter planes did have one sighting, but the four whale sharks dove too quickly for us to track them.
Oceana and the University of Southern Mississippi have not given up and will continue the search Tuesday.
Here’s Oceana marine scientist Elizabeth Wilson:
It wasn’t until we reached Grand Isle to drop off the shark experts that we saw a school of what appeared to be silky sharks.
During transit, the experts spent time talking with Associated Press reporter Rich Matthews. One thing is clear, no matter what direction you look in the Gulf of Mexico, there are always oil rigs in the landscape.
Predators as Prey: 10 Threatened Shark Species
We often tell you about the threats facing sharks globally -- finning, bycatch, overfishing -- but we don’t regularly shine a spotlight on the individual species affected.
To continue our ongoing shark-themed posts in honor of Shark Week, here are 10 of the most threatened shark species in the world:
1. Basking sharks are the second largest shark, easily distinguished by their huge, filter-feeding mouths. Basking sharks are caught in target fisheries around the world for their oil, meat and fins, and they are also caught as bycatch in other fisheries.
2. Blue sharks are one of the most previously abundant shark species. Now they are the most heavily fished shark in the world. An estimated 10-20 million individuals are killed by fisheries annually, mostly as bycatch. Blue shark meat is beginning to replace swordfish in many Mediterranean countries and the fins are commonly used in shark fin soup.
3. Deep-sea sharks have huge livers that contain high amounts of oil to regulate their buoyancy at depths. As a result, they are caught by deep-sea trawls, gillnets and longlines for an oily substance found in their livers called squalene. Squalene, or its derivative squalane, is found in many cosmetic products.
