60-foot-long Whale Shark Sighting is Double their Average Length

Google Alerts pinged this week with news of a 60-foot-long Whale Shark spotted in the Pacific Ocean. The Whale Shark, Rhincodon typus, is the world’s largest cartilaginous fish, with a maximum length of up to 21 metres, or 68 feet, although average length is less than half that, at 5.5-10 metres, or 18-33 feet, with females always being the larger sex.

Despite the news of the sighting, the news stories published in the Daily Galaxy and Wion are vague and lack any evidence, with no first-hand reports, photos or actual measurements. Both news sources also confined the sighting to the “Pacific Ocean,” an area of 60 million square miles. 

The kid in me is still fascinated by gigantism in the animal world. Giants of all species are becoming rarer because of hunting and all the associated human-related risks that prevent wild animals from living long enough to attain their maximum size. Also, when we seek out and kill the largest individuals, we remove their giant genes, preventing giants from developing in the future. 

So I was going to throw this one out as a non-story. Wikipedia quotes many giant whale sharks up to 20 metres, but it’s not a trusted source for many. So I hit up my favourite ichthyological source Fishbase, and was pleased to find that mega whale sharks of 60 feet long or more do appear to be true. 

According to Fishbase, maximum length of up to 21 m and weight of up to 42 tons and an age of 80 years have been reported in a scientific paper on the age and growth of Whale Sharks, so giant octogenarian female whale sharks may still be out there somewhere, and capable of a litter size of over 300, 55cm long pups.

And no, I couldn’t let this one go without a bus comparison! A double-decker bus is 14 metres, or 46 feet long. That makes our sixty-footer one and a quarter times as long as a bus, and longer than a Hump Backed Whale!

The natural world never ceases to amaze…