Recently, I published with my colleagues from Te Papa Fish Team and Massey University some interesting findings about a fantastic group of species: hagfishes. Those primitive deep-sea fishes repulse any predator attack using their slime. I present examples of how hagfish stop the attack from shark several times their sizes. And it even looked easy… The paper also documents a first ever observed predating behaviour of hagfishes in the wild. We thought they were only eating dead or dying animals, but now we know that they can also hunt for preys. Combining this with the fact that hagfish have existed on Earth, almost unchanged, for 300 millions years and are the ancestors of all vertebrates, they are quite impressive animals! You can download the open-access paper here.
Those videos got National Geographic attention and were published on their website where you can find other examples of amazing animal behaviours. It is well worth having a look at. Follow this link to the National Geographic video.
The seal shark, Dalatias licha, attacking the common hagfish, Eptatretus cirrhatus
In the meantime, our team is getting ready for another expedition. In about ten days, we are heading down South for almost one month of intensive sampling. This time, we will study fish biology and behaviours off the Otago Peninsula and around the Auckland Islands which are part of the Sub Antarctic islands. This is an amazingly wild place to work on! I will post in the coming days more information about this exciting survey.
Not many of you will believe that hagfish, also called snot-eels, are fascinating creatures, but they truly are. You will only be able to believe me after reading this post. I still persist saying that I am not falling in love with them but some of my colleagues start worrying about my desire to always know more on their behaviour. Another step in this direction, I just published with colleagues from Te Papa, Massey University and the University of Western Australia a paper describing new extraordinary behaviours of my current favourites.
Hagfish teeth. Hagfish are equipped with four rows of keratinous teeth that they can use to grasp and bite flesh from dead animals or live prey.
Hagfish are deep-sea primitive fishes which have been living on Earth for at least 300 millions years, almost unchanged. They are like living fossils and scientists wonder how it is possible that they could survive for such a long time on Earth. To give you an idea of how long 300 millions years is, keep in mind that the dinosaurs appeared on Earth about 230 millions years and went extinct about 65 millions ago. With this research, we reveal a few more clues on what make hagfishes so special.
Hagfish were thought to fulfil primarily the ecological niche of scavengers in the deep ocean, i.e. we thought they were feeding on dead animals only. Reviewing video footage taken in New Zealand waters, we now know that they are also able to hunt for live preys such as fishes. During a video deployment off Great Barrier Island at 97 m depth, one hagfish species was successfully observed predating on a red bandfish.
But there is more. After carefully reviewing over 1000 hours of underwater video footage, I realized that not a single shark or other large fish could bite and feed on hagfish. Hagfish versus sharks and co: 1-0! What happens is that every time a large fish tries to attack, the hagfish produce large amount of slime at incredible speed. This slime then clogs the gills of those would-be predators which start choking, unable to breathe. Amazingly, not a single attack resulted in successful predation! This is an extremely effective defence mechanism, totally unique.
The paper describing those two newly observed behaviours can be downloaded here from the journal Scientific Reports.
Te Papa fish team is off Kaikoura onboard the MV Star Keys to study deep-sea fish fauna.
We have just finished our third day of sampling off Kaikoura. So far, everything goes well, and we are progressing at a good pace with our sampling. It has been difficult to have an internet connection, but now we have one.
We were expecting slime during our Kaikoura fieldwork, and we are not disappointed! Have you ever heart about hagfishes, sometimes better known as snot eels? They are fantastic animals, but most probably, you need to be a scientist (and a somewhat strange one) to state this and love them. Those fishes look very primitive but are extremely successful in their biotope. They have existed in one form or another for more than 300 million years on earth, placing them at the origin of vertebrates.
Vincent cleaning one hagfish specimen from its slime (and, yes, I am Belgian!). Te Papa.
Several specimens of hagfish interlaced. The white substance is the mucous they produce. Te Papa, photograph by Vincent Zintzen.
Hagfish teeth. Not difficult to understand that they are very efficient scavengers of the deep. Te Papa, photograph by Vincent Zintzen.
Their common name comes from the faculty they have to produce mucus which is exuded through the many pores they have on their skin (usually more than 200). This mucus combines with sea water and creates a characteristic slime. Amazingly, a single specimen can produce at least his weight of slime very quickly!
Three days at sea and we have already collected over 100 specimens. Definitely the most common species so far. Our clothing is covered with slime and we are fighting to extract them out the trap they have been caught with. But all those efforts are worth the price: they truly are an interesting group of fish to study.
Carl extracting hagfish specimen out of one fish trap. Te Papa, photograph by Vincent Zintzen.
Speak to you soon and I hope you will not have nightmares because of me…
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