High school teaching intermezzo

Last month I had to make a short and unexpected trip back to Belgium. In the short time I was there, two friends who are high school teachers decided to enlist my services to teach a few guest classes. So I (rather surprisingly) ended up talking to a bunch of 14-to-16- year-olds about how great weird fish are.

To say that this was a different crowd to my usual audience (scientists, enthusiastic divers, etc.), would be a bit of an understatement. Communicating about the ocean with teenagers living in a big city, most of which have never snorkeled in their lives, was a refreshing challenge. How do you get high school kids whose main interests are.. (what are they even?) to listen to stories about fish?

Turns out the trick is….the same way as getting most other people’s attention: by piquing their interest with stories about gore and sex,  and cool videos. Not of the gore and sex (that wouldn’t be allowed in high school I think). Showing videos of hunting frogfish, or of flamboyant cuttlefish wandering around definitely worked better than just pictures. Not-so-much to my surprise, telling stories about the aberrant mating habits of fish and comparing it to teenagers’ normal school interactions with the opposite sex also seemed to get their attention. So much actually, that it inspired me to write the sex under the sea post from last month!


Not my usual setting – teaching in a high school in Belgium

Valentine special: Sex on the sand

In the aftermath of valentine’s day, I figured a post about nautical naughtiness was suitable. Popular media such as romantic comedies, reality tv-shows or more dubious videos available on the internet might have you believe that a moonlit fondle on a tropical beach is the highlight of romance. They are, however, very much mistaken! Late night walks on the beach turning into passionate, steamy scenes of desire and lust are in fact the best way to discover that sex and sand really don’t mix well. No matter how hard you try, sand will get where you absolutely don’t want it to get. But for creatures that spend their entire lives on soft sediments there is no way around it. They have no choice but to deal with the gritty truth that is sex on sand. As you can imagine, this blog is not going to be a pretty story, but if you think you can handle it, here is how things go down in the muck…


A small male frogfish (Antennarius pictus) risking his life to get closer to a larger female

Getting started with one my favourites, frogfishes, immediately proves my point on how difficult romancing is on the sand. As in humans, competition for females is fierce, but competition is made worse because frogfish are usually quite rare, so there aren’t many females around. The result is that males will often stalk a female for multiple days or even weeks, waiting until she might be ready to mate. This is a very risky strategy though. At best, the larger female will reject a male by pushing him away or swimming off. At its worst, the grumpy female might decide to eat the male! It sure would make Tinder a lot more exciting if this trend would catch on in humans. Have a look at a cannibalistic frogfish below (Video by Albert Kang).

When the female frogfish is in the mood however, the male will gently put its pectoral fin on her belly when they’re almost ready to mate. He’ll prod her until she’s ready, at which point the female swims up, partially pushed by the male, and releases her eggs. The male then releases his semen over the eggs, after which the now fertilised eggs drift off, forming a sort of raft until the young frogfish hatch. The attentive blog-reader will have noticed that frogfish also avoid the sand when mating, clever! Here is a rather explicit video of two hairy frogfish in action (video by BlueWaterLife1)

Unlike frogfish, the blue ringed octopus wastes no time on small talk or courtship. Male blue ringed octopuses just pounce upon any opportunity, inserting their hectocotylus (scientific slang for “penis-arm”) in any other blue ringed octopus they encounter. The problem is that males unfortunately can’t tell the difference between males or females. So they will try any octopus and only know if they hit the jackpot or got themselves into a rather embarrassing situation until after attempting to copulate (not unlike some drunk male tourists in dodgy bars in Thailand or the Philippines). The unfortunate males on the receiving end don’t seem to take it too badly and do not react aggressively, preferring to wait passively until the mistake becomes obvious. The females however are more feisty and tend to finish the act by “forcefully pulling the males from their body“, occasionally attacking or even killing and eating the males (is it me or am I seeing a trend here?). The actual deed takes on average 90 minutes, but I think we can all agree it hugely lacks in romanticism.

Best of Dauin_Blue ringed octopus_small

A blue ringed octopus on the prowl. For what I don’t know, and turns out neither does he…

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Male Thorny seahorse (Hippocampus histrix) showing off its pregnant belly

Seahorses are more romantic, forming stable couples that sometimes stay together for life. The couples greet each other every morning by doing a little dance. When mating their dance gets more elaborate and ends up with both fish swimming up in the water-column and doing the act at the highest point of their dance. But then it gets a bit kinky, as it is the female who penetrates the male! She deposits her eggs in the male’s pouch, who then fertilises the eggs, gets pregnant and gives birth to baby seahorses. Shortly after giving birth the couple mates again (within as little as 30 minutes for pygmy seahorses!), and the males gets pregnant all over again. No rest for these little guys!

At least for nudibranchs life is a bit simpler, there is no such thing as a male or female nudibranch, since they are both at the same time. It is believed that being hermaphrodites (simultaneously male and female) is an adaptation to being rare and not being able to move very far during their lifetime. After all, you wouldn’t want to spend half of your life on your own, getting increasingly horny, to then finally meet a single other individual of your species and find out you can’t reproduce with them. So when nudibranchs mate, they usually get pregnant and make the other one pregnant in one go, talk about efficiency. Being efficient at mating does not mean mating is a boring occasion. Nudibranchs are some of the most deviant critters in the ocean. They occasionally indulge in mating aggregations (aka orgies),  S&M (most of their penises have backward pointing spines), mating with different species than our own (a slug’s a slug), and some species even practice protandry (adults mating with juveniles). But it gets even worse….


Nubibranch sex: These Gymnodoris nudibranchs clearly show how both animals penetrate each other at the same time

Some species amputate their own penis after mating, mostly because pulling out is just too much effort with those backwards pointing spines. They do have spares and the amputated penis regrows, so no harm done. In what is probably one of the most bizarre cases of sex on the sand, a species of Siphopteron-slugs uses a part of its forked penis to stab its partner through the head during mating! You read that correctly, they use an adapted penis to stab each other in.the.head while having sex. Not the mouth, not any other orifice, the head, right above the eyes. As if that’s not enough, they even inject prostate fluid into the head as well. A process beautifully coined as “cephalo-traumatic secretion transfer”. Call it what you want, this stuff is a bit too kinky for my liking. Oh, and the reason why? You guessed it…we don’t know, although researchers have suggested it might change the behaviour of the receiving slug, go figure…

As you see, sex on the sand is a lot more complicated (some might argue interesting) than in more conventional places. Try to remember that during your next romantic walk on the beach.







Critters in the deep

Some of you might have noticed the exciting news last week that the third species of seadragon has been filmed in the wild for the first time. Others, not living in Australia might now go “Huh? 3rd species?” or even “Huh? Seadragon?”. Which is completely fine, they are very cryptic species and it makes me feel like I can teach people something new 😉 The special thing about this new critter is that it lives in deep water, so I figured it was time to look into what critters are to be found below where divers can go.


Ruby seadragon (Phyllopteryx dewysea) (Source: WA Museum)

Let’s start with this new seadragon species, the Ruby seadragon (Phyllopteryx dewysea). It was described in 2015 and is found only in deep waters in the south of Australia. It is a cousin of the Leafy and Weedy seadragons, but mostly differs from them in the fact that it lives a lot deeper: below 50m. Besides the very exciting fact that there is a third species, it is also very interesting to see how it differs from other seadragons. The Ruby seadragon is ruby red, which is a great colour to camouflage yourself in deeper water. Unlike its cousins, the deep species does not have any appendages (the fancy frills so typical for the other seadragons). The explanation is once again pretty simple, there is not enough light for plants to grow in the environment it lives in, so it does not need the frills to resemble plants and maximise its camouflage. Another difference is that this new species has a tail that can wrap around objects, which the other dragons do not have. Have a look at the Ruby dragon in the video below:

We will stay with the pipefish and seahorse family for more deep species. Pygymy seahorses are a favourite for many divers, but what is virtually unknown is that there are no less than 2 species of pygmy seahorses that have never been seen alive and only live in the deep! The Bullneck seahorse (Hippocampus minotaur) and Hippocampus paradoxus (does not have a common name yet) are very mysterious species which we literally know nothing about. The Bullneck seahorse is only known from a couple of individuals found below 60m while trawing the bottom. The other species was discovered at 100m also using bottom trawling, only 1 animal has ever been found. They are a bit bigger than the shallow water pygmy seahorses (4cm to 6cm) and might live on gorgonian seafans or on bryozoans. Both of the species have only been found in Australia, the Bullneck seahorse in the southeast, H. paradoxus in the southwest of the country.


Larger Pacific Striped Octopus (Source)

Octopus are amazing animals, not only because most of them look cool and are very intelligent, but also because they show some really interesting behaviour. Divers are used to seeing species like mimic octopus or coconut octopus on the sand in shallow water, but some species venture much, much deeper. Larger pacific striped octopus (LPSO) can be found all the way down to 300m. They live in the eastern Pacific Ocean, in places like Panama and Nicaragua. Despite being an extremely interesting species, the LPSO has still not been scientifically described. Unlike most other octopuses, this species seems to like living in groups, sometimes of up to 40 animals. LPSO are beautiful animals that behave differently from other octopus species. They mate “beak-to-beak”, where other octopuses seem to prefer mating from a distance, or mounting on top of each other. Unlike shallow water octopuses, the female LPSO does not stop mating after it lays its eggs. Instead they keep on laying new eggs and mate with other males for much longer. There is good news for octopus-enthusiasts, this species does not only live in the deep sea, it can sometimes live shallow enough for scuba divers to be able to reach them.


Details of the Larger Pacific Striped Octopus (Source: Caldwell et. al 2015)

It would not be possible to talk about deep critters and leave out frogfish. Most non-divers only know about the existence of deep-water frogfish (although they might call them anglerfish) and not about their shallow cousins. I guess the scene in Finding Nemo with the big-toothed, bioluminescent anglerfish has got something to do with that. But in case there is any doubt, the shallow water frogfish and deep-water anglerfish are related. They all belong to the order of the Lophiiformes. The deep-water species generally look quite scary, with large teeth, dark colours and beady little eyes. Which makes me love them even more 🙂 Two interesting adaptation for the deeper species: they often show bioluminescence (produce their own light) to attract prey, which shallow species don’t do (although they might use biofluorescence). Another thing some species do, is mate in a very peculiar way. The males are a lot smaller than the females, once they find each other (which is rare in the deep sea), the male will attach itself to the female with its jaws. Over time, the male and female fuse together, the male basically becoming a parasite that receives all its nutrients through the female. This has major drawbacks for the male as well, since it will slowly shrivel up and become not much more than a pair of gonads attached to the female, serving no other purpose but to provide semen when she is ready to mate. Life in the deep…it’s quite something.


A deep-sea anglerfish (Caulophryne pelagica) (Source: National History Museum

If anything, having a closer look at deep-water critters has made me very curious about what else is out there. Searching for those elusive pygmy seahorse is something that got me particularly interested. I might have to become a technical diver after all, just to go find the little guys.



Why the ocean matters and why we should talk more about how awesome it is…

This week I attended the CommOcean 2016 conference in Belgium. CommOcean was all about marine science communication and what the best ways are for marine scientists to interact with the general public. Science communication is about more than just reaching non-scientists, but also about making an impact and transforming how people perceive the ocean, it’s about making a positive change. But why would anyone really care about the ocean, or even more, change their day-to-day behaviour for it? A question particularly relevant if you live far away from the sea or don’t have a taste for fish.


The CommOcean2016 crowd in front of the beautiful conference venue in Bruges

The thing is, the ocean matters big time, for everyone, everywhere. On a global scale, the ocean produces more than 50% of the oxygen we breathe (more than trees!). If breathing isn’t your thing, the ocean also provides other trivial things such as food, cures to certain cancers and other diseases, a way to transport most goods around the globe (90% of international trade), and so much more. Current human impacts such as climate change can and will have effects on everyone, even those living furthest away from the sea.

For the people fortunate enough to live close to the coast, the ocean is even more important. Over 1 billion people depend on the sea as their main source of protein, which explains why overfishing is such a big issue. Besides food, the sea also provides a way to make a living as fishermen, through trade, industry, or tourism (muck diving being only one example). For people living on low islands, rising sea levels are a very real and very large threat. Entire countries might sink below the ocean and will have to move elsewhere. Countries like Tuvalu and Kiribati are already negotiating with Australia about possibilities to move their entire population there. Popular holiday destination Maldives has even gone further and is already buying up land in other countries to prepare for relocating its people.

Communicating ocean science is often challenging when people aren’t faced with the ocean in a way the Maldivians or other islanders are. Not being able to see what is below the waves might be the biggest challenge to get people to care about our oceans. It is hard to comprehend  just how amazing life in the sea can be without diving in it, or without the help of talented filmmakers and photographers to show us.

The fact that many scientists are still perceived to live in their “ivory tower of knowledge”, without interacting with people does not help either. The issues facing the oceans are often more complicated than those on land and often seem overwhelming. If the only news people hear about the oceans is bad news, they won’t be keen to listen to the yet another doomsday talk. Most marine scientists are not trained to be communicators and are often too worried about oversimplifying their message, resulting in nuanced, scientifically correct communication that is unfortunately understand by nobody else but scientists. Lastly, in a world where Twitter, Facebook, etc. are increasingly the main source of information for people, it is hard to get attention with a science message. After all, who wants to read about weird fish, if you could be reading about what a Kardashian had for breakfast or that your favourite soccer player went wild on a party last night?


Rita Steyn explaining the ins and outs of Twitter

So what is the solution? How do you get the message across that the oceans matter? I’m in no way an expert, but luckily there were experts around at CommOcean. The first step is to adapt you message to the people you are talking to, don’t go wild on the crazy science talk, have a clear message. (in case you forgot: “Oceans are awesome! Get the news out there!“). Ideally try to interact directly with the people to whom your research is important, stop talking over people’s heads and listen to what they care about. Using social media is a good thing, but do it right and don’t get stuck on just one method. Not everyone uses Twitter or visits websites about science, many people don’t have smartphones and might prefer written media, etc. Don’t forget that humans are visual animals, presenting your message in a more attractive way than dry text will get more attention.


Lastly, maybe most importantly, don’t forget to give the good news. There might be a load of bad news out there, but the ocean is still a beautiful place, something I feel everyone should know about too. Telling people about the beauty that can be found and offering practical tips on how to do something about protecting it can go a long way.

In the long run, what we really need is ocean science to become ingrained in all levels of education. As one of the most important ecosystems in our world, the ocean deserves more attention. After all, as long as people are not aware of the importance of the ocean (and the issues facing it), they cannot change their attitudes about the ocean and they will definitely not change their behaviour to preserve it.


PS: In the spirit of using different communication channels, crittersresearch is now also live on twitter as @DeBrauwerM.

PS: All photos sourced from the CommOcean2016 Facebook page