Iron Chef: Crab Edition

The culinary battle between chefs to find out whose cuisine reigns supreme!


Chairman Kaga of the Iron Chef series demands an interesting showdown!

Unfortunately, crabs cannot afford such luxuries like gas stoves, fancy knives or even cuisines for that matter. Crabs are known to be scavengers, feeding on many things from algae to detritus (aka dead matter). With the life of the scavenger, one must become accustomed to eating garbage. As humans frequent beaches often, we leave plenty of random food for our marine friends to eat. This can provide alternative food sources for many animals on a consistent basis.

Here on Iron Chef: Crab Edition, we will find out the food preferences of crabs. This shall be our stand in for their “cuisine”. Their preferences for such “cuisine” is a complete mystery for us. Some may argue that because they are scavengers, they have no preference at all! I say nay, and here we shall find out favourites of our crustacean, Hemigrapsus oregonensis.


The Arena, with various foods in each corner. The crab is feeding on the banana.

During this round of Iron Chef, we have our choices between cuttlefish, bananas, seaweed, and chips. In my little arena, I have performed many trials and have found that crabs seem to prefer cuttlefish and bananas. I suspect that the higher nutritional value of cuttlefish would be very tempting for the crabs. However they appear to dislike the tough muscles of the mantle portion of the cuttlefish, which are used to pump water for breathing and locomotion.

Bananas, the odd food choice here, are also seen to be a favourite. Many reasons could lead to why the humble banana is top tier food for crabs. Crabs are known to rely on their sense of smell through tiny chemical receptors on their antennae. The banana is also very mushy and breaks apart very easily in the water. Through the tiny particle trails left by the banana in the water, the crabs are able to detect their scent of bananas and find the source much more easily.

Seaweed and chips were not well received on the other hand. As they were mostly used for hiding underneath. However crabs eating chips are not unheard of!


From the results of the clash between foods, we now know the crabs seem to like soft, easy to fall-apart food. That is the cuisine that reigns supreme!


The temperature plan: a new way to get your beach body

Calling all barnacle friends!

Are you looking to get back into shape? Tired of dieting and stressing over what you eat? 100-day ab challenges not working for you? If you answered yes to any of these, then have no fear! I am going to teach you a simple trick that will get you that beach body you’ve always wanted. Don’t worry, I’m not making you do cross fit or anything, it’s actually quite simple. The secret to getting your summer body has to do with one easy thing…temperature!

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Skeptical barnacles photo from:

Some of you look confused but yes, you heard me correctly! Temperature is the key to getting your beach body. Bear with me for a second while I try to explain this. You guys (barnacles), are ectothermic animals. As an ectotherm, you are unable to control your own body temperature, so this means that the temperature of your environment has a large influence on your internal body temperature. Why is this important you ask? Well you see, body temperature effects your metabolism—the process by which you turn food into energy. This is important as it determines how long it will take you to break down your food, and it could influence how much you need to eat. So you see? As ectotherms, your metabolic rate is directly affected by the temperature of your surrounding environment. No Fitbit’s or vitamins necessary, if you want to control your metabolic rate and how much you eat, all you have to do is pick a place where the water temperature suits you best.


If you would like to slow it down and eat less, I would suggest going somewhere cold. In colder temperatures, the metabolic rate of ectotherms is decreased. So while you won’t have very much energy, you also won’t need to eat much due to the lower metabolic demands. This is great if you don’t want to be too active, but fair warning, you might just become a couch potato forever. Not my choice in lifestyle but hey, to each their own.

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Low metabolically active couch potatoes photo from:

For the crazy active yogi bear barnacles, I’d recommend going somewhere hotter, where your metabolic rate will be increased. Having a higher metabolic rate increases the amount of energy that is available to your body, so you will definitely be able to live that active lifestyle! However, to keep up with this life you better eat a lot, and I mean, A LOT. With such a high metabolic demand, you’re going to need to eat all the time or you will burn out.

If you’d still like to live an active life, but not have too high of a metabolic demand, I’d suggest you search out waters with temperatures near your thermal optima. I know those are science-y words, so let me explain. An organism’s thermal optima describes the ideal temperature range that an organism can live in. Within this range, processes such as growth and development are most efficient. Since I am a person who likes to eat and live somewhat of an active lifestyle, this is the temperature range I’d go searching for.

So now you know all about temperature and its effects on metabolism. However, if you’d like to learn more check out this site and video. Good luck figuring out which temperature plan works best for you. I hope you all end up with a great beach body like this guy!

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Barnacle boy photo from:


“A Study in Scarlet”

“A Study in Scarlet” was written in 1886 by Arthur Conan Doyle. It marked the first appearance of the famed Sherlock Holmes and Dr. Watson and sparking multiple generations of “Sherlockians”.

Sherlock Holmes is a “private” detective of crime, murder and mystery.  Similarly to a scientist, he uses the scientific method to use clues to solve problems. One clue leads to the next, and so forth until he catches the criminal.

My detective story started at Tower beach looking at yellow shore crabs (Hemigrapsus oregonensis).

Despite the colour “yellow” being in their name, they in-fact are not very yellow at all! Adults are more greenish, and juveniles come in various colour morphs; beautiful combinations of crimson green, daring yellow, plush pink, pale white, plump purple and passionate red. These clues lead me to ask a question; can these tiny shore crabs actually see the plethora of colours related to their magnificent colour morphs?

I did some literature searches on google scholar and found another clue: most crabs (decapods to be precise) are dichromates-meaning they have two colour receptors usually in the bluish-greenish end of the colour spectrum. Therefore they cannot see the colour “red”. In the literature however, there was nothing specific about the vision capabilities of the little yellow shore crab… Can they see the colour red? This lead me down my own detective story: “ The yellow shore crab.  A study in red”.

I came up with two possible hypothesis about the yellow shore crabs ability to see the colour red:

(1) The yellow shore crab is a dichromate like most decapods therefore is red colourblind.

(2) Since the yellow shore crab is a trichromate (three colour recpetors) and can see the colour red.

Inspired by my own personal hero Sherlock Holmes, I continued too look for more clues to answer my hypothesis…

In the lab (in summary) I ran a coloured choice experiment to see if yellow shore crabs could distinguish between light, shade, blue light, green light and red light. I also measure a behavioural response to light, shade, blue light, green light and red light by observing their change in locomotive ability.

My experiments hinted that the yellow shore crab may be red colour blind; however, my experiments were not 100% conclusive. In order to confirm that they are red cloud blind, I need to perform more experiments to look for more clues…

I challenge you to be your own detective and never stop looking for clues or asking questions. Wether that is being a detective of crime, murder and mystery like Sherlock Holmes, or a detective of scientific innovation and discovery!

How mucous might make your snail pal cooler than you!

Have you ever racked your brains trying to find a restaurant for dinner, only to turn to your favorite food blogger for inspiration? Have you ever been overwhelmed by the sheer number of delicious food options on a menu, only to turn to pictures posted by food bloggers to make the ultimate decision?

I definitely have. And so apparently do periwinkle snails! While humans “follow” food bloggers on Instagram and other social media websites, snails literally follow each other in search of meals. How cool is that?

Let’s start with a little background. Periwinkle snails are primarily herbivorous creatures. They scour the intertidal zone looking for delicious algae to chomp on. If you’ve ever seen a snail crawl about, you may have noticed that they leave behind a wet-looking trail. This ‘wet-ness’ is actually mucous! Like other snails, periwinkles produce mucous trails, a sticky substance made of proteins and sugars which helps them attach to surfaces!

It just so happens that periwinkles use their mucous trails to follow others who have recently eaten! In the same way that humans take pictures of their food and post them all over social media in order to broadcast to the world what they’ve just eaten, once snails have ingested a full meal, their mucous trails change composition to broadcast to other snails that they’ve recently eaten well! Happening upon these trails, latter snails can choose to follow the fed snail in hopes of discovering the fed snail’s food source.


A periwinkle eating algae off a rock. Photo from:

Mucous trails can also help periwinkles find mates. For us, finding other members of the same species is as simple as pulling out a cellphone and calling a friend, or whipping out Tinder, or even finding a nice, quiet cafe.

For snails, it’s not so easy. As inhabitants of the intertidal zone, they are faced with a constantly changing environment. With the tides coming in and out twice a day, the landscape is rarely ever the same. The crashing waves push rocks around, shuffling the entire intertidal landscape around. Imagine living in a city, where twice a day, everything, including shops, streets, restaurants and grocery stores, are rearranged and shifted around twice a day. That would be enough to turn anyone around.

Unfortunately for snails, cellphones and phone apps like Tinder, don’t exist. Even “meeting spots” like cafes are hard to come by when the entire landscape shifts overnight. Snails, resilient as they are, have found a way to cope using their mucous trails! It turns out that their mucous trails themselves contain chemicals that allow the snails to recognize members of their own species, facilitating reproduction and the birth of many new snail babies!

While there’s no doubt in my mind that snail mucous trails are undeniably cool judging by the number of uses they have, I think for me personally though, I’d prefer technology to mucous trails – makes for less of a mess and way fewer questions.


For more information on periwinkles, check out:

For more information about periwinkle mucous trails, check out:

Heating Up Hermit Crabs

When I started thinking about what to study for my BIOL 326 independent research project, I immediately thought of some annoying snails at my local beach (below). These invasive snails coat the sand during the summer, so I wanted to see how tolerant they are to thermal stress.

However, when I went to the beach to collect them I had a shocking discovery; they weren’t there. There were plenty of shells, but when I picked one up I found they were actually hermit crabs! Specifically, they were hairy hermit crabs (below), which can be found from California to Alaska and are pretty common in the intertidal zone. I then made the executive decision to perform my experiment on hermit crabs.

After an late night at the beach gathering data I collected a bunch of hermit crabs and drove home. I left the crabs in my garage overnight (my mother was thrilled) and came back to them in the morning. To test how my hermit crabs would respond to high and low temperature stress, I removed them from the garage and placed them in either high, medium or low temperatures. How did I achieve these conditions in my house you ask? Easy! I stuck them either in the fridge (again, with full support of my mother), kept them in the garage, or placed them directly underneath my desk lamp.

Next comes the interesting part, seeing how the hermits responded to the thermal stress. To accomplish this certainly took a little trial and error, but hey, that’s science for you. What I came up with was two containers of water, as shown below, for the crabs to move around in. These were over top of one square inch grid paper and the whole apparatus around the containers allowed me to time lapse their movement. Looking at the film, I counted how many squares the crabs moved through and was able to estimate how much they moved in twenty minutes. Comparing the average amount of movement between the temperature treatments would let me see any effect of temperature, but I didn’t end up finding any.


Image credit: Myself

Now, you may be wondering why I went through all this trouble in the first place. Well, climate change is increasing global temperatures, and this can have dramatic consequences for the animals on our planet. It is all too possible that animals such as the hairy hermit crab could disappear from their ecosystems and biodiversity is believed to be a key component in ecosystem health and performance. Therefore, I wanted to know if increasing temperatures would cause these crabs to leave the intertidal zone ecosystem, potentially hurting other members of that ecosystem.

If you aren’t convinced that hermit crabs are amazing creatures worth studying, please check out this video of hermit crabs literally lining up for shell upgrade!

An Underwater Symphony

Symphonies are usually music to our ears, but what about from a crab’s perspective?

How do people talking, the humming noises in a building and their acoustic resonation in your ears affect your performance? If you’re studying, are super focused or are used to studying in noisy environments, perhaps this noise doesn’t affect you at all. However, in a new environment with new or unusual noises, your attention will likely be more impaired than normal. These negative effects of noise on performance may be what animals experience too in their natural habitats.


Anthropogenic noise, noise produced by humans, is recognized as a major pollutant of the 21st century. And as populations increase, this noise will likely follow, resulting in stronger impacts on animals, their interactions, and thus their ecosystems. Anthropogenic noise is thought to be a stressor on animals as it impairs their attention and cognitive resources. Lack of these skills may decrease anti-predatory and feeding behaviours, both key to survival. Even more unfortunate, noise may affect their ability to detect and consume non-toxic food. Don’t the effects of noise on crabs seem so much more taxing than noise on humans? Though, I guess if noise repeatedly impaired our sleep cycles, our lives would be greatly affected too.

Seemingly an important topic, I studied the effects of ship noise, a primary source of underwater noise, and human crowd noises on Hemigrapsus oregonensis, a shore crab abundant on the west coast.


H. oregonensis (shore crab) in the foraging experiment with a selection of mussels and seaweed as food choices. Photo credit: Jessica Chiang

For my study, I tested whether crab’s anti-predatory and foraging and feeding behaviours were affected under different sound conditions. To measure anti-predatory behaviour, I created a shadow over the crab to simulate a predator, and measured righting time, the time it took for a crab to flip over. During the feeding experiment, many of the crabs didn’t eat the food, but when they did it was a sight to see—I’ve never seen a crab so intensely pull apart a mussel—check this out.

Surprisingly, I did not find any significant effects of noise on these behaviours, though that’s part of science…back to the lab with more studies. Does noise really not impact a crab’s performance, maybe only if they’re already used to it? It would be intriguing to see if different types of noises have varied effects on crabs; I’m sure noise frequencies, levels and their key properties impact you and I differently, so wouldn’t crabs be similar?

Next time you’re walking along the beach, think about how ship noise or a chattering background, seemingly a normal environment to you, may have amplified effects on crabs and the many animals sharing this same world.

If you’re interested in learning more about this topic, check these studies out.

Wale et al. (2013)

Chan et al. (2010)


The Slow and the Furious

Have you ever seen the movie The Fast and the Furious? A movie about illegal street racing where a group of racers try to defeat the villain. This movie always results in a high-speed chase at the very end and the racers have to adjust their speed in order to face all of the obstacles that the villain throws at them. The same scenario applies to Littorina littorea. They are always trying to adjust their lifestyle according to the changes in the environment. The villain in their life is climate change and predators, and in order to fight against the villains they have to change their behaviour.

Littorina littorea also known an periwinkle, are gastropods that are found in the intertidal zone and these regions are always facing environment variations such as change in salinity, temperature and pH. In addition to the climate change, they have to escape and find refuge from predators in order to survive. As you can see they are always under pressure.

In order to find out how climate change and predators play a role in influencing Littorina littorea’s behaviour, I conducted an experiment. This experiment consisted of placing periwinkle into a petri dish that had sea salt water. The sea water was changed to a high and low temperature and salinity. As well I added Hemigrapsus oregonensis cue water to determine the effect of predatory and prey relationships. I measured the distance they travelled every minute up til 5 minutes and found the average distance travelled per minute. This became my crawling speed.

The results were astonishing. Unlike the Fast and the Furious where they drive fast to capture the villain. Periwinkle’s crawling speed decreased for all of the variations except crab cue water. For crab cue water there was no difference in speed compared to the control.

Periwinkle definitely would not be able to overcome the villain in the Fast and the Furious but  they were able to overcome the villain in the Slow and the Furious by decreasing their crawling speed.

To learn more interesting facts about periwinkle, click the links below: