TOADTalk: My Nudibranch Teacher
Heather Grant shares her enthusiasm for sea slugs and what we can learn from them.
Each week, an All-School Assembly launches with the Teacher On Active Duty (TOAD) sharing something of interest—a reflection, a story or song, a demonstration of some sort, or a simple poem. In this way, the community gets to know one of our own a little better. Recently, our TOAD was Heather Grant. Ms. Grant teaches science, advises junior girls, coaches girls’ soccer and lacrosse, and is a faculty advisor for the EAC’s bee program and the Sustainability Council. Her TOADTalk is below.
Hi everyone! If you haven’t met me yet, I’m Ms. Grant and I teach science here. I’m also a parent to two kids under the age of six and we spend a lot of time learning and talking about animals. My kids’ list of favorite animals changes a lot. Can you all think of your favorite animal (either current or maybe one from when you were little)?
It’s a difficult question for me to answer, but nearly all of my favorite animals are marine invertebrates. If you’ve ever been with me to the tidepools, you’ll know that I could talk endlessly about the organisms that live in this dynamic habitat.
I’ve always found marine invertebrates fascinating, at least partially, because it just feels like vertebrates really should be cool and so when I learn about the details of the life of a marine invertebrate it’s doubly impressive because of their relative lack of complexity. So, today I'm going to tell you some facts about one of my favorites and how those facts might inform or inspire our everyday lives.
Sea slugs—nudibranchs. Their name means ”naked gills.” They are mollusks: relatives of clams, snails, octopus, squid, etc. They are small and for the most part, algae grazers.
Here are the three facts:
First and most obvious:
Coloration.
Many nudibranchs are known for their bright and beautiful coloration patterns; some nudibranchs use this cryptic coloration to blend in with their colorful habitats like coral reefs but others use it as warning coloration to avoid predation—their bright colors let predators know that they are toxic. Their colors are so vibrant and so varied that they inspired a Tumblr called Bowiebranchia that pairs nudibranchs with images of David Bowie with corresponding outfits. (This site is so awesome that it was originally my inspiration for this talk, to be honest.) What can we learn from their coloration? Don’t be afraid to be yourself—people are often quick to judge, but if your natural state is striped or splashed in color (or not), own that and go forth with gusto. Just like David Bowie (or the nudibranch) when you’ve found your genuine sense of self, your confidence will shine through. And likewise, don’t judge a book by its cover and keep an open mind about nudibranchs (and people who might dress or look differently from you). Think about how much you will miss out if you limit your interactions to people just like you (or to studying charismatic megafauna).
Coloration.
Many nudibranchs are known for their bright and beautiful coloration patterns; some nudibranchs use this cryptic coloration to blend in with their colorful habitats like coral reefs but others use it as warning coloration to avoid predation—their bright colors let predators know that they are toxic. Their colors are so vibrant and so varied that they inspired a Tumblr called Bowiebranchia that pairs nudibranchs with images of David Bowie with corresponding outfits. (This site is so awesome that it was originally my inspiration for this talk, to be honest.) What can we learn from their coloration? Don’t be afraid to be yourself—people are often quick to judge, but if your natural state is striped or splashed in color (or not), own that and go forth with gusto. Just like David Bowie (or the nudibranch) when you’ve found your genuine sense of self, your confidence will shine through. And likewise, don’t judge a book by its cover and keep an open mind about nudibranchs (and people who might dress or look differently from you). Think about how much you will miss out if you limit your interactions to people just like you (or to studying charismatic megafauna).
On to fact number two, and this is when things get really awesome:
Kleptoplasty/nematocyst poaching/chemotoxins.
Sea slugs have a habit of ingesting (but not digesting) chemicals or structures from their prey and using them to their advantage. Remember that instance of warning coloration? The sea slugs don’t actually synthesize their own toxins, they eat other organisms like sea sponges and incorporate the chemotoxins from the sponge into their own tissues. Other species are known as nematocyst poachers. They eat the tentacles from anemones or siphonophores like the Portuguese Man O War and rather than getting “stung” by the mini-harpoon-like, chemotoxin laced barbs, they are able to pass them to the surface of their own bodies where the nematocysts develop and become an active defense mechanism for the sea slug.
Kleptoplasty/nematocyst poaching/chemotoxins.
Sea slugs have a habit of ingesting (but not digesting) chemicals or structures from their prey and using them to their advantage. Remember that instance of warning coloration? The sea slugs don’t actually synthesize their own toxins, they eat other organisms like sea sponges and incorporate the chemotoxins from the sponge into their own tissues. Other species are known as nematocyst poachers. They eat the tentacles from anemones or siphonophores like the Portuguese Man O War and rather than getting “stung” by the mini-harpoon-like, chemotoxin laced barbs, they are able to pass them to the surface of their own bodies where the nematocysts develop and become an active defense mechanism for the sea slug.
Others do something called kleptoplasty, where instead of stealing nematocysts they steal plastids (which are basically like chloroplasts) from algae, and instead of breaking down that food for energy they incorporate the photosynthetic organelles into their tissue and can produce their own food source via photosynthesis...which would be like eating a salad and instead of getting the small amounts of energy we get from the spinach, becoming photosynthetic for a while after each salad and not needing to eat lunch for a few days.
Be inspired by the coolest things your peers/community members do—if you’ve got a friend with an impressive skill or ability, find inspiration in that, or if you’re the one with the skill/ability share that with others so we can all grow together and benefit from the collective best we can all do.
On to the last and weirdest fact:
Autotomy.
The last sea slug fact is a newly observed and rather extreme version of autotomy, which is the intentional shedding of body parts. You might be more familiar with lizards that drop their tails if a predator (like a house cat) grabs it by the tail. Here’s where some species of sea slug take this idea to the next level. People have observed sea slugs that intentionally shed their entire bodies (!) basically from the “neck” down...then the heads just crawl around and slowly regenerate their entire body (17 days to full regeneration!). The individuals displaying this behavior have some things in common—they exhibit kleptoplasty (so they are photosynthetic to a degree) and they are also infected with copepod parasites which led researchers to suggest that the sea slugs are shedding their bodies as a way to rid themselves of the parasites.
Autotomy.
The last sea slug fact is a newly observed and rather extreme version of autotomy, which is the intentional shedding of body parts. You might be more familiar with lizards that drop their tails if a predator (like a house cat) grabs it by the tail. Here’s where some species of sea slug take this idea to the next level. People have observed sea slugs that intentionally shed their entire bodies (!) basically from the “neck” down...then the heads just crawl around and slowly regenerate their entire body (17 days to full regeneration!). The individuals displaying this behavior have some things in common—they exhibit kleptoplasty (so they are photosynthetic to a degree) and they are also infected with copepod parasites which led researchers to suggest that the sea slugs are shedding their bodies as a way to rid themselves of the parasites.
So here’s the last bit of inspiration and one that I have personally found to be particularly true during the course of this pandemic: Be radical about what matters and what doesn’t matter in your life. Identify what old habits or mindsets or cultural paradigms are holding you back—get rid of them like the parasite-ridden body of a sea slug and then rely on your individual strengths and relationships with your community to come back stronger.
Photo credits: Boredpanda.com
Photo credits: Boredpanda.com
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