Jumping Giants!

So now we are on the countdown toward Christmas I thought I would try find something a bit special to chat about… how about 2.3 tonnes of fish exploding vertically out of the water up to 10 feet in a beautiful breach before belly-flopping back down into the deep!

sunfish breach

Sunfish breaching is a relatively rare event… like my use of photoshop :s

Yes this really happens! Sunfish can actually work up enough power to breach well above the sea surface, see this news story form 2005 about a family having one flop into their boat off the coast of Wales!  http://news.bbc.co.uk/1/hi/wales/4192566.stm

The reasons behind such an extreme behaviour are still unknown, but it has been suggested that such leaps and splash downs are an attempt to dislodge parasites or to scratch these irritations. Other large marine species such as humpback whales, spinner dolphins and basking sharks all breach, although these may also be displays of fitness to impress mates, communication signals, signs of stress or perhaps for the sheer joy of it!

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I took this photo during a summer working as a research assistant satellite tagging basking sharks in the Isle of Man where a group of common dolphin began swimming in the boat’s bow wave and breaching. They certainly appeared to be enjoying themselves!! (NB we did see one breaching basking shark too… but sadly the photo of that is just one big splash!)

Many marine species are also observed swimming whilst regularly breaking the water’s surface in a movement known as “porpoising”. This differs slightly to the individual large breaches as seen in sunfish, as porpoising is a regular leaping behaviour undertaken whilst travelling. This provides a more energetically efficient method of swimming at high speeds, however this will only occur when an animal, such as a seal or penguin, is swimming close to the sea surface after a specific ‘cross-over’ speed has been reached when the leaping behaviour becomes more energetically efficient.

For a brilliant paper describing this in more detail (including how to calculate animal energy use), try reading Blake’s article from 1983 about the energetics of leaping dolphins:

http://journals.cambridge.org/download.php?file=%2FMBI%2FMBI63_01%2FS0025315400049808a.pdf&code=0651ebff2aebaadae332fec41a70bb64

Breaching events are relatively rare in sunfish but luckily I have access to a single photo (credit to Valentina Cappanera) showing a sunfish neatly breaching to jump out of a fisherman’s net in Italy!

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Fancy a chat about fish / jumping for joy / Christmas? Get in touch! 😀

Tweet @sunfishresearch or send me an old fashioned email: nphillips01@qub.ac.uk

(especially if you find a dead sunfish as I am looking for tissue samples!!)

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