How To Protect The Ocean
SUFB 113: Krill Species Profile
This Species Tuesday I decided to profile Krill as they are small but hugely important in the sustenance of some major iconic species such as baleen whales, fish, and penguins. They are found all over the world so I thought it would be good to find out a little more about them.
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http://www.speakupforblue.com/session113
Welcome to the Speak Up For Blue Podcast, session 113. Today is Species Tuesday. We are going to be profiling a species that we don't normally profile, or group of species that we don't normally profile. That is the krill species, which are in lower parts of the food chain. Usually the iconic species that we cover are at the above, like apex predators. Today we're gonna be going on lower end of the food chain, but very, very important. So we're gonna talk about krill species. Stay tuned for this episode of the Speak Up For Blue Podcast. (upbeat music) Welcome to the Speak Up For Blue Podcast, helping you get involved in ocean conservation. And now, here's your host. He just discovered Periscope and might be slightly addicted. Andrew Lewin. (upbeat music) Hey everybody, welcome back to another exciting episode of the Speak Up For Blue Podcast, your voice for the ocean. I am your host, Andrew Lewin, founder, speakupforblue.com, marine ecologist and self-proclaimed ocean printer. And today, I have to admit, as I'm recording this, I'm recording this on a Sunday, and this is gonna be a Tuesday, obviously, it's a species Tuesday, but I'm recording this because I'm actually away. I'm actually, as you're listening to this, I'm actually with my family at an indoor water park in Niagara, Ontario, which is kind of fun for us. We're getting our blue mind on while you guys are listening to this. And because usually we don't go to water parks at this time of year, so I'm a little psyched because it's freezing cold. And at the time of recording this on a Sunday, it's actually minus 30 outside, degrees Celsius outside, and that is pretty cold. So we're inside, I decided to record some podcasts for this week. It's a great time to do so, but it's beautiful outside. It's actually quite sunny and bright and no clouds. It's just quite nice. So it's kind of a fun to, in my office, actually stare outside on the road, but I get to see the sky and everything through my skylight up here, and I can tell there are no clouds, just kind of nice, bright and sunny, but freezing cold. So it's a quick walk for the dog today. Anyway, let's get to what we're gonna talk about today. Before we do though, I want to thank the people who support us on Patreon on patreon.com. So that's Chris and Claire Jefford, Ron and Judy and Dr. Judith Weiss. Thank you very much for supporting our campaign to raise awareness of ocean conservation through podcasting. If you want to support us, you can go to www.speakupforblue.com/patreon, P-A-T-R-E-O-N. And you can put in a specific amount per month that supports us. We're trying to hit some major goals that will allow us to get to other platforms and raise awareness of ocean conservation, ocean issues, how to solve those issues through other platforms, such as digital magazines, video and so forth. So we really appreciate if you can support us through that platform. Anyway, let's get on with Krill. Let's learn all about Krill. So normally with Krill, they're very small organisms. Okay, they feed a lot of iconic species, such as baleen whales, which include humpback whales, blue whales and so forth. They also feed fish and some penguins, believe it or not. So, and they also feed us. In the Philippines, it is known as alemang. And it's used to make a salty paste called bagoon, bagoon, bagoon, B-A-G-O-O-N-G. So it's kind of a cool thing to do. A lot of people will catch Krill for commercial fishery so they'll use them in agriculture or aquarium feeds. They'll use them as bait for sports fishing or they'll use them in the pharmaceutical industry. Japan, Philippines and Russia, Krill is also used as for human consumption. In Japan, it's known as the oceami and I told you what it is in the Philippines. So, a lot of people and species are interested in Krill. And luckily, there's a lot of Krill out there. There are over 379 thousand or 379 million tons of biomass. So it's more than humans on the in the ocean of at the Antarctic Krill, Eufosia superbob. Okay, so it's definitely well distributed. There's no real conservation status of this. I'm not sure if there is because there's so many of them, but they do feed a lot of species, a lot of important iconic species and almost apex predators at some point. So it's kind of an interesting thing. Now, they are part of the large arthropodus subphylum called the crustacea. So when we talk about species, we talk about how they're categorized, right? We talk about the animal kingdom, how they're the taxonomy, how they're classified. So they're in a subphylum, the arthropod subphylum called crustacea. The most familiar of the largest groups of crustaceans, class malachostra, includes the superorder eukaryda, comprising of three orders, Eufosia, which is the Krill, decopata, which are shrimp, prawns, lobsters, crabs, and the planktonic amphionites. So there are a lot of different species within that that we know and love. Obviously, the decopata orders are very popular, lobsters, prawns, and so forth. And it's just nice to have for your meal and seafood and so forth. But the Eufosia, Eufosia, it comprises of two families. The most abundant is the Eufosia day, contains 10 different genera of a total of 85 species. Of these, the genus Eufosia is the largest with 31 species. The lesser-known family, I'm gonna try and pronounce these, properly, Benthufosia has also one species in Benthio-Fosia amplyobes, and bathapalagic, a bathapalagic krill living in the deep waters below 1,000 meters, is considered the most primitive and extent krill species. So there's a lot, so that the Eufosia species, genus, is probably the krill fisheries. They're probably most well-known for the krill fisheries, including Antarctic krill, which is Yofesia superba, which we've been talked about, the Pacific krill, Yofesia Pacifica, and the Northern krill. Yofesia mega nystic tafani's nor vijica. So, obviously, very difficult to pronounce, and I apologize for anybody who knows Latin, and I'm butchering these names. It's been a while since I've gone through these pronunciations. But anyway, the distribution, the krill occur worldwide in all oceans, although many individual species have endemic or neurotic, which are coastal distributions. So the bathapalagic species has a cosmopolitan distribution within a deep sea ocean habitat. Some species of genus thysenosia occur in both Atlantic and Pacific oceans. The Pacific is home to Yufosia Pacifica. Northern krill occur across the Atlantic from the Mediterranean Sea and Northward. Some of the species with neurotic distributions include the four species of genus Nick tafani's. There are highly abundant, along the upwelling regions of the California Humbot, Bengulia, and Bengula, and the Canaris current systems. Another species having only neurotic distributions is e-crystalilofoia, which is endemic to the Antarctic coastline. So now you gotta remember, you're probably wondering, like, why are you reading all these names and all these distributions? For me, distribution is most important. It really gives you an idea of a picture of where these krill are found. Now, obviously, there are a lot of krill species out there. They're found throughout the world's oceans on the coast and on the deep sea and in the open ocean. They're very important areas, or they're very important food for large migrating species, as well as some coastal species that don't migrate very far. So it's important to know that there are some that are neurotic, which are coastal distributions, and some that are just open ocean and deep sea distributions. They do have a, what they call a, what is it here? Sorry, I lost it. They have, I forget the word, I'm sorry, it's blanking on it, but what they do is they actually, it's just, sorry, I wanna find this word 'cause it's really bothering me here. Where is it here? Anyway, diurnal. They have a diurnal lifestyle, so during the day, they stay in the deep sea at night, they float to the top to feed on phytoplankton. Actually, they follow phytoplankton. They eat phytoplankton and some zooplankton. They have a diurnal lifestyle, so at night, they float to the top and at the bottom, during the day, they float down to the deep sea. So of course, animals will follow that, animals who eat them will follow that diurnal, that diurnal lifestyle, and they will go down to the bottoms during the day and stay at the top to feed at night. So it's kind of a cool life history that they have. The life cycle of a krill is relatively well understood, despite minor variations in detail from species to species. After a krill hatched, they experienced several larval stages. I'm not gonna bother reading the names. There's one, two, three, four, five larval stages, each of which divides into sub-stages. So one of them at the stage is exclusive to species that lay their eggs with an enovigara sac, so-called sac spawners. The larvae grow and molt repeatedly as they develop, replacing their rigid exoskeleton when it becomes too small. Smaller animals molt more frequently than larger ones. Yoke reserves within the body nourish the larvae through the meta-nopolis stage, by the kettle-oppa stage differentiation has progressed far enough for them to develop a mouth and a digestive tract within, and they begin to eat phytoplankton. So you see that they grow after they're hatched, they grow, they have different stages, they have an exoskeleton, a clear exoskeleton actually, and that exoskeleton will actually molt and crack and then allow them to grow more and more, just like other crustaceans. So it's kind of an interesting way of doing things. The lifespan, some high latitude species of krill can live more than six years. Others, such as the mid-latitude species, Ephosia Pacifica live only two years. Subtropical or tropical species longevity is still shorter. The nyctifani simplex, which usually lives only six to eight months. So it's kind of interesting, but one thing, the interesting thing is they swarm, they're known as swarming, so most krill are swarming animals. The sizes and densities of such swarms vary by species and by region. For Ephosia's superba, which is the Antarctic species, swarms reach 10,000 to 60,000 individual per cubic meter. Wow, swarming is a defensive mechanism, confusing smaller predators that would like to pick out individuals. In 2012, Konami and Elavi, these are authors presented what appears to be a successful stochastic algorithm for modeling the behavior of krill swarms. The algorithm is based on three main factors, movement induced by the presence of other individuals, foraging activity and random diffusion. So it's kind of interesting how they do that. It's a defense mechanism. You wouldn't think that shrimp that small would actually have any kind of defense mechanism. You didn't think they'd be that sophisticated, but I thought that would be kind of an interesting thing. They're a vertical migration, which I mentioned earlier, critically follow a diurnal vertical migration until recently it has been assumed that they spend the day at greater depths and rising at night toward the surface. The deeper they go, the more they reduce their activity. Apparently to reduce encounters with predators and conserve energy. Swimming activity in krill and krill varies from stomach fullness. Saciated animals that have been feeding at the surface swim less actively and therefore sink below this mixed layer. As they sink, they produce feces that implies the role of the Antarctic carbon cycle, which implies a role in the Antarctic carbon cycle. Krill with empty stomachs swim more actively and thus head towards the surface. Vertical migration may be two to three times daily occurrence. Some species, Euphoria, Sephora, Pacifica, Hensini, pseudo-Ephosia, Lata frons, and these thynastial thysenosa, spinnifera formed surface swarms during the day for feeding and reproductive purposes, even though such behavior is dangerous because it makes them extremely vulnerable to predators. Then swarms can elicit a feeding frenzy among fish, birds and mammal predators, especially near the surface. When disturbed a swarmed scatters and some individuals have been observed to molt instantaneously, leaving exuvia behind as a decoy. Krill normally swim at a pace of five to 10 centimeters per second, that's two to three body lengths per second, using their swim rates for propulsion. Their larger migrations are subject to ocean currents. When in danger, they show an escape reaction called lobstering, flicking their coddle structures with their tail, their talons and their uropods. They move backwards throughout the water relatively quickly, achieving speeds in the range of 10 to 27 body lengths per second, which for large krill, such as euphoria's suburbia, means around 0.8 meters per second, it's three feet per second. The swimming performance has led to many researchers to carefully adult, to classify adult krill as micro-necked on life forms. Small animals capable of individual motion against weak currents. Larval forms of krill are generally considered zooplankton. So it's an interesting species, and it's you, like I said before, it's used all around the world by not only iconic species, but by us as well. We harvest it, we feed it as bait fish, we feed it to agriculture industries, and we also consume it for human consumption in some places in the world. So I wanted to cover this because I just think, obviously I don't know a lot about it. I was reading off a Wikipedia page and some other sources, but it's interesting. I just find this such a small species that feeds so many other species. I just find that interesting, and I think that people should know about it. So that's sort of why I want to cover it today, even though I haven't, I don't know a lot about it. So that's why we learn. That's why we keep this species Tuesdays going. So I hope that was getting informative for you. That's our show. If you want to help support our ocean conservation message, you can go do so at speakupforblue.com/patreon, P-A-T-R-E-O-N, and we thank you for your future contributions. And that's it for the show today. Thank you for watching, or even listening to the Speakup for Blue podcast, I'm your host, Andrew Lewin. Happy species Tuesday, and happy conservation. (upbeat music) (upbeat music) (upbeat music) (upbeat music)