Our survey onboard the MV Tranquil Image has started after a rough transit from Wellington to Dunedin.
After a very successful day 1 deploying camera and traps in the shallow (50 and 100 m), today we have started exploring the deep canyons of the area some 25 nautical miles from the coast. The sea wasn’t the calmest this morning, but everybody seemed to enjoy the bouncy travel towards the 1200 m depth contour line. We have managed to deploy six video systems and four fish traps at depth ranging from 300 to 1200 m. Today’s highlight was surely the presence in high numbers of Owston’s dogfish (Centroscymnus owstoni) on the videos and also on the fish traps at depth 500 to 900 m. We caught a good size range from juveniles (15 cm) to adults (1.1 m) which will be very useful for future taxonomic studies. They were observed on the video feeding by taking a mouthful of sediments to find little benthic preys, expulsing the mud and sand by their gills. An unnoticed behaviour so far.
Scientists and crew prepare the deployment a fish trap to be sent in the deep canyons off Otago Peninsula
Te Papa scientist Carl Struthers holding a large specimen of Owston's dogfish just caught in a fish trap at 700 m depth
We were expecting to catch some hagfish in the area, but could not see any on the video, and none were attracted by the bait of our traps. We are hoping that the next days will bring the discovery of their presence in the area.
A hermit crab caught in the trap tries to grip onto a little fragment of probable coral
I will keep you posted on what’s going on here in a few days.
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.
The Kermadec Islands’ are the most isolated piece of rock that New Zealand has, some 1,000km North of Tauranga, right in the middle of very deep oceans. The isolation, recent geological origin and predominantly subtropical marine flora and fauna make them unique both nationally and internationally. I often imagine the Kermadec as one of the last untouched area on the planet.
Many species found at the Kermadecs do not occur on mainland New Zealand. The limited sampling to date has discovered that almost every major taxonomic group studied so far, with the exception of the algae and corals, has one or more species endemic to the islands.
On Wednesday, I am leaving with a team of Te Papa scientists to work on the fish fauna of this fantastic location. It’s going to be a three long days trip steaming to Raoul Island, the main island of the Kermadec. Then, we will mostly do video and collecting work, deploying systems from the shallow and colourful 50m depth zone, to the dark deep-sea waters beyond 1500m where no light penetrates. It is a very exciting time and I expect lots of new discoveries out of this survey. Hopefully, I will be able to share them with you with the help of satellite communication. Thank you technology!
More to come later…
Vincent
Our Boat heavily loaded with gear during our previous survey off Kaikoura.
The other lectures have been filmed and will be available in the middle of next week, provided we are able to edit them fast enough.
First videos
Discovery Channel, who have been supporting us in the preservation of the colossal squid specimen, have edited videos and gathered resources on their news website.
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