Is it white or basking?

Posted by on May 23, 2014 in Sighting Updates | 2 Comments

Last week, we urged anyone that has seen a White shark in Canadian waters to please report it to the Shark Identification Network. Researchers from the Atlantic White Shark Conservancy, who are tagging White sharks off Cape Cod are trying to collect as many White shark sightings in Canadian waters as possible, to help them better understand White shark movements in the North Atlantic. We are working with them to help collect White shark sightings from Newfoundland to the Gulf of Maine.

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Of course, the most important part about reporting a White shark sighting, is that it is indeed a White shark! The Atlantic White Shark Conservancy gets many reports of White sharks every year off the coast of the eastern United States, however most of these reports are actually Basking sharks, that were misidentified as White sharks. In fact, it’s not uncommon to see a photo published in a newspaper or online news site showing a “White shark” swimming close to shore with sunbathers looking on. However, upon closer inspection, the “White shark” is actually a Basking shark.

The basking shark and white shark share many similarities, such as large size and overall body shape, making identification difficult. So, how can you tell the difference between a Basking shark and a White shark?

1. Dorsal fin:

Both sharks have large, conspicuous dorsal fins but the top of the dorsal fin (apex) for a Basking shark is rounded, whereas the White shark’s dorsal fin is pointed at the apex.

Difference in dorsal fin shape between a basking shark and a white shark. Image taken by video produced by the Massachusetts Marine Fisheries Division. See video at: http://www.youtube.com/watch?v=1NoO7ZWJ5LE

Difference in dorsal fin shape between a basking shark and a white shark. Image taken from video produced by the Massachusetts Marine Fisheries Division. See video at: http://www.youtube.com/watch?v=1NoO7ZWJ5LE

 

2. Body characteristics

The basking shark is uniform in colour (although, sometimes has a mottled pattern) whereas the white shark has a very distinct two-toned body colour–they have a very white underside.

The gill slits of the basking shark are very large and wrap almost completely around their head, whereas the gill slits of the white shark are only at the side of their head.

Difference in dorsal fin shape between a basking shark and a white shark. Image taken from video produced by the Massachusetts Marine Fisheries Division. See video at: http://www.youtube.com/watch?v=1NoO7ZWJ5LE

Difference in body characteristics between a basking shark and a white shark. Image taken from video produced by the Massachusetts Marine Fisheries Division. See video at: http://www.youtube.com/watch?v=1NoO7ZWJ5LE

Since misidentified basking sharks account for most of the reported White shark sightings that they receive, John Chisholm, of the Massachusetts Marine Fisheries Division’s Shark Research Program, made this excellent, short video on White shark identification, which clearly shows how you can distinguish the two species. Please check it out http://www.youtube.com/watch?v=1NoO7ZWJ5LE

2 Comments

  1. Mary Doherty
    May 27, 2014

    I’m not an expert but i am a marine life enthusiastic geek! And have watched hundreds of documentrys! And I definitely could be wrong lol but that looks like a great white juvenile that some other shark has had a go at!

    Reply
    • sharkid
      May 29, 2014

      The markings on the side of the shark that look like they could be shark tooth-rake marks are actually the shark’s gills slits. The White shark, like most sharks, has 5 gill slits. Some sharks such as the broadnose sevengill shark and bluntnose sixgill shark on Canada’s Pacific coast, have more than 5.

      Reply

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