Our friend Steve Haddock at the Monterey Bay Aquarium Research Institute has posted a video called “There’s no such thing as a jellyfish.” It surveys a broad diversity of animals that are clear and squishy, and explains why there is no one group called “jellyfish”. Many different groups of animals, from stinging cnidarians to swimming snails, have independently become free swimming, gelatinous, and transparent.
Gone Fishing
This video was taken by a submarine sent down into the ocean to collect deep sea animals. While you’re watching it, pretend you’re driving it remotely from a dark room that’s swaying back and forth, on a boat 600 meters above the submarine, and you’ve been watching marine snow fly by like stars for the last several hours.
One of the perks of working with jellyfish is going to sea to collect them. The Dunn lab occasionally gets the chance to join our friends from the Haddock lab, at the Monterey Bay Aquarium Research Institute (MBARI), on a week-long excursion out into the Pacific Ocean.
About nine scientists from different labs, about five submarine pilots, and a full boat crew leave from Moss Landing aboard the Western Flyer. Once we reach deep water, we stop driving and drop the submarine into the ocean. The submarine that lives on this boat is called Doc Ricketts. It is about 7 feet tall, has propellors, cameras, lights, collecting buckets, spatulas, and measuring instruments. A crane lifts Doc Ricketts off the floor, the floor opens up to reveal the surface of the sea, and the machine is gently lowered into the water.
This is not the type of submarine that people can travel in. Rather, it has a 2.5 mile umbilical connecting it to the boat, where the pilots are driving it around remotely from the control room, while watching a live, high-definition video feed of what the submarine is seeing.
The control room is a dark little cave on the boat. If you are not driving, controlling the camera, or keeping records of the animals, you can sit in the back and watch the marine snow fly by on the screen as the boat rocks deeply back and forth. When someone spots a shadow that looks like an animal, they shout ‘stop!’ and the pilots drive closer to it. Sometimes it turns out to be a decaying blob of sea-lint, but with any luck it’s an intricate radiolarian, or an elusive vampire squid, or some other beautiful creature. After getting a couple of minutes of close-up footage, which is sometimes the only record of the animal as it exists in the wild, we will either collect it in one of the buckets on the submarine, or keep on flying.
By the end of the night, the pilots have brought the submarine back into the boat, hopefully with all 20 collecting buckets full of interesting animals in their native water. Every one lines up and passes the buckets into one of the labs on the ship, and begins sorting through them and looking for their animals. Amidst the excitement, renowned scientists can be heard saying things like ‘Look at this, have you ever seen anything so magenta in your life?’
Some folks will put their animals in the lab’s walk-in refrigerator (with lids, so they don’t slosh out of their bowls with the rocking of the boat) to look at another day. Some will stay up until the wee hours at their microscopes, processing the samples as quickly as they can while the boat speeds through the night to the next destination. In this photograph, Dr. Claudia Mills is gently taking a Paraphyllina out of one of the sampling buckets (from a depth of 2360 meters), so she can draw it and take notes before sunrise, when the submarine will be lowered into the water again.
All of these photographs were taken by Sophia Tintori during a research cruise last year, except the control room photograph, which was taken by Stefan Siebert on a cruise earlier this month. The video of the humbolt squid is also from this recent cruise and it provided graciously by the Monterey Bay Aquarium Research Institute. All photos are released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license.
Jellyfish Capsule Hotel
These little pinkish crustaceans have set up house inside the muscular pulsating swimming parts of the colonial jellyfish, Nanomia. Out in the deep sea, there are few solid structures to call home, so living things will often take shelter in or on other animals.
Fish or bugs often hang around the tentacles of jellyfish because the jellies catch food there and are likely to drop pieces that can be salvaged. But these crustaceans are taking a different approach. They are living inside of swimming bells that are nowhere near where food is caught and eaten. These powerful little pods contract to push the colony through the water. The amphipods are likely to be taking refuge in the sturdy tissue, and feeding off the jellies flesh from the inside of the swimming bell.
Stefan Siebert, a post-doc in the Dunn lab, took this photograph of a Nanomia that he caught on a collecting trip in California. The gas-filled gland that keeps the colony afloat is hanging off the left side of the page. Three swimming bells for jet propulsion (with one amphipod crustacean in each) are seen in the middle. The part of the colony that feeds, reproduces, protects, and more, starts in the bottom right corner of the photograph. These amphipod crustaceans happen to be very similar to the ones we just made an animation about, that live on the fried egg jelly.
Here is a video from Casey Dunn of some other colonial jellyfish, to get a sense of how this close up photograph fits into the context of the whole colony, and to see how the swimming bells pulsate.
This photograph, by Stefan Siebert, is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license.
CreatureCast – Siphonophore Snacks
Here’s a short episode featuring Trisha Towanda, of the fried-egg jelly story. If you’ve ever wondered what a siphonophore taste like, it’s spicy.
Puppetry and editing by Sophia Tintori, with slightly modified music by Anita. Sea snow from deep sea footage courtesy of Dr. Steve Haddock at the Monterey Bay Aquarium Research Institute. This video is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license.
CreatureCast- Jellyfish Theater
In the vast ocean, without walls and far from the floor, jellyfish can become drifting islands of activity. Creatures from far and wide will congregate on them to act out the ups and downs of life and death. Jellyfish have symbiotic relationships with living things of all sizes, from fish and shrimp that feed off them or off the pieces of food left between their tentacles, to single-celled photosynthesizing organisms that take shelter inside the cytoplasm of the jellyfish’s cells.
In this video, Trisha Towanda talks about one particular jellyfish, the fried egg jelly, and some of the other creatures that hang around it. There are moon jellies that the fried egg jelly eats. These moon jellies have little parasitic crustaceans on them called amphipods, which jump to the fried egg jelly while the moon jelly is being eaten. There are also crabs that ride around on the fried egg jelly, that are parasitic in their youth, but then grow to be helpful symbionts by eating off the little amphipods. This sort of coming of age story, where a symbiont’s relationship changes over its lifespan is an unusual one. Trisha put the pieces together by staring at them for hours and days and weeks when she was in Erik Thuessen‘s lab at Evergreen State College.
Many thanks to Trisha Towanda, who is now stationed in the Seibel lab at the University of Rhode Island. This video was edited and animated by Sophia Tintori, with an original score by local pop hero Amil Byleckie. It is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license. Here is the paper Trisha wrote about the story.
More Budding Jelly Babies
We found more jellyfish being born in our lab this week!
Rebecca Helm, a Dunn lab graduate student, left a couple of bowls of salt water and hydroids out on the table overnight, instead of the refrigerator where they usually live at around 50 or 60 degrees fahrenheit. The next day she came in and found them doing this:
This particular animal is called Podocoryna carnea. Like most jellies and close relatives of jellies, it has a pretty elaborate life cycle. This one involves a free swimming jellyfish, and a larva that swims around then lands on the back of a hermit crab’s shell. Then the larva metamorphoses into a polyp, which buds more polyps, growing into a whole colony on the crab’s back. The colony is made up of lots of polyps that are all connected and share fluid through a web of tubes that circulate partially digested food. Some members of this colony will eventually bud new swimming jellyfish.
The video at the top is of one of the colonies we have growing in our lab. These polyps were given to us by friends, but they can also be collected from hermit crabs at the beach, then grafted onto slides. They seem to grow well on slides, and slides are much easier to take care of then crabs.
Some of the polyps in the video have pink balls growing around the top. These are the buds that will mature to become free-swimming jellyfish. If you look closely, you can see jellies of all stages of maturity growing, including some that are ready to break free. After they swim off they will continue growing. We’ll try to follow up on how that goes.
Video by Sophia Tintori, life cycle drawing by Perrin Ireland, both released under a Creative Commons Attribution-Noncommercial-Share Alike license. Thanks to Diane Bridge and Neil Blackstone for the Podocoryna colonies. Check out this earlier post of the other polyps we saw budding jellyfish in our lab.
CreatureCast – Individuality
Last month we posted a video of a siphonophore (one of the Dunn lab’s favorite animals) swimming freely in the ocean. In this next installment of CreatureCast, Casey Dunn describes how siphonophores help us question what we think of as an individual.
There are different ways to think of individuality. Individuality can refer to function- whether an organism operates and interacts with the world as a unit. A fish is a functional individual, but so is an ant colony. Individuality can refer to evolutionary descent. In this respect our liver is not an individual, there was no ancestral free-living livers out there that our liver is descended from. But our mitochondria are individuals in this sense. They evolved from free-living bacteria that became incorporated into other cells. Individuality can also refer to the process of evolution. In this sense an individual is any entity that has the properties necessary for evolution by natural selection- it reproduces and has variable heritable properties that influence the chances of survival. This could be a free living cell, a cell in a body, an entire multicellular organism, and even groups of organisms in some cases.
All of these definitions of individuality are in alignment in most of the organisms we are familiar with. A bird, a rose bush, and a fly are all individuals as functional entities, according to their ancestry, and as units of selection. This makes it easy to get lulled into thinking of individuality as a monolithic property.
A siphonophore colony is a functional individual. But a siphonophore colony is made up of many parts that are each equivalent to free living organisms such as sea anemones and “true” jellyfish. So by the evolutionary descent definition it is a collection of individuals. The colony as a whole is acted upon by natural selection, making it an individual in the sense of the process of evolution. But it is entirely unclear whether natural selection can act on the parts within the colony, as it does on our own cells when we get cancer, since we don’t know about the heritability between the parts of the colony.
Siphonophores, by forcing us to disentangle what we mean when we call something an individual, help us understand the evolutionary origins of individuality. These different aspects of individuality don’t necessarily evolve at the same time, and one or more of them can even be lost. Organisms like siphonophores provide glimpses of these different combinations of individuality.
Most of the stills are plates from the first papers describing siphonophores. They were published from the mid 1800′s to the early 1900′s by Henry Bryant Bigelow, Ernst Haeckel, and Karl Vogt.
The song New Homes is by Lucky Dragons, the siphonophore video is from Dr. Steve Haddock at MBARI, the podcast was produced by Sophia Tintori, and the video is published under a Creative Commons Attribution Non-Commercial Share Alike 3.0 license.
CreatureCast – Diving for Jellies
Here in the Dunn lab, siphonophores are our favorite animal and the focus of much of our research.
Dr. Phil Pugh is a good friend of the lab, and he also happens to have described more new species of siphonophores than anyone who has ever lived. In the video below, he describes what it’s like to come across a siphonophore in the deep sea with a submarine. What looks like one long body in this video is actually a free-swimming colony of clones — many genetically identical bodies that are all attached. But each body in the group isn’t just like its neighbor. They each do a specific job for the colony. Some individuals will swim, some will catch food, and some will reproduce.
More on siphonophore biology can be found in papers here and here. But we’ll talk about all that later — for now, just take a look.
Footage courtesy of the Bioluminescence lab at the Monterey Bay Aquarium Research Institute. Music graciously provided by Raf Spielman of The Golden Hours. Edited by Sophia Tintori. This podcast is published under a Creative Commons Attribution Non-Commercial No Derivatives 3.0 license.
Royal jellies
Emperor Hirohito was a man who wore many hats. Most famously, he was Japan’s head of state during World War Two. As emperor, he was the stoic and elegant embodiment of Japan. But he was also a family man, a poet, and a marine biologist.
Hirohito had the Imperial Biological Laboratory built for him when he was 24, which was substantially upgraded three years later when he became the emperor. It contrasted the rest of the Imperial Household in the plainness and usefulness of its furniture. Plain furniture, such as a trash bin made out of a trophy elephant leg.
He would steal away every Saturday afternoon and most Thursdays when he could, to his lab where he would meet with other biologists to identify and describe the species that they had dredged up from the surrounding waters. He had a gentle touch when working in the field. If collecting from a colony of polyps, he would take only a small bit of each colony and would put the rock carefully back in place, so as to let the rest thrive.
After the war he published 32 books of plates, describing some 23 new species of ascidians, 7 new species of crabs, 8 new species of starfish, and 6 new species of pycnogonids. He conducted the first comprehensive survey of the biodiversity of Sagami Bay, but he was particularly well versed in the tiny tentacled polyps that grew on the sea floor, called hydrozoans. All of his work was published under the name ‘Hirohito Emperor of Japan.’
At the top is a photo of Emperor Hirohito with his wife, whose hat is making her look a bit like a hydrozoan herself. Next down is Emperor Hirohito in the Imperial Laboratory, from E. J. H. Corner’s article about Hirohito’s scientific career. Below that is an illustration of a nudibranch (left) from Opisthobranchia of Sagami Bay (1949), and an illustration of a coral (right) from The Hydrocorals and Scleractinian Corals of Sagami Bay (1968), by Hirohito Emperor of Japan. Below is a photo of Emperor Hirohito in Kurume, also in 1949.
Stack of plates in action
Look what we caught happening in our refrigerator.
While doing a fridge clean-out in the Dunn Lab, graduate student Rebecca Helm took a look at a forgotten bowl of Chrysaora colorata polyps from our friends Chad Widmer and Wyatt Patry at the Monterey Bay Aquarium. These creatures were left over from an RNA extraction we had done earlier for the Cnidarian Tree of Life Project, and were hidden in the back of the fridge, despite the labs strict ‘no pets’ rule.
Upon inspection, Rebecca noticed that the polyps were strobilating! This is a spectacular type of asexual reproduction, which is explained in more depth in Perrin Ireland’s post on the scyphozoan life cycle.
In this video, a polyp has pinched off into a stack of plate-like discs, called ephyrae. When they pop off of the end of the polyp, they each become a free swimming individual, and a direct clone of the parent polyp. Each ephyra will mature into adult bell-shaped jellyfish. Even before they break away from the poly, they are strongly pulsating as they flex their newly developed swimming muscles before birth.
Video by R. Helm and S. Siebert.