Six tips for achieving invisibility

posted by Sophia Tintori / on April 15th, 2013 / in Arthropods, Cnidaria, Comb Jellies, molluscs, optics

 Hiding from danger in the deep sea is a very different game than hiding from danger on land. In the sea, not only does a creature have nothing to hide behind, it can’t even camouflage itself, because it’s environment is just clear water. Perhaps not surprisingly, then, many animals of the sea have evolved ways of being transparent.

Here is a semi-interactive video (with the option of a single, non-interactive video here) from CreatureCast alum Sophia Tintori, featuring tips from a handful of ocean-dwellers that each have drastically different approaches to being invisible.

Score by Amil Byleckie, video made by Sophia Tintori, with a big thanks to Sönke Johnsen. Funding provided by Duke University Provost & Council for the Arts and the Office of Graduate Education at the University of North Carolina Chapel Hill. Released under a Creative Commons Attribution-Non Commercial-Share Alike license.

CreatureCast – Rhizocephala

posted by Casey Dunn / on January 4th, 2012 / in Arthropods, Parasites, Podcast (Student Contribution)

Stephanie Yin, from Casey Dunn’s Invertebrate Zoology (Biol 0410) course at Brown University, tells the story of a parasitic barnacle with a fascinating lifecycle.

The hand-drawn animations were photographed at the Brown University Science Center. Thanks also to the Granoff Center for the Creative Arts.

Music by King Vitamin, Lino del Vecchio, and Val.

CreatureCast – Jumping Spider

posted by Casey Dunn / on January 4th, 2012 / in Arthropods, Podcast (Student Contribution)

Amber Harris, from Casey Dunn’s Invertebrate Zoology (Biol 0410) course at Brown University, tells the story of jumping spider courtship.

For more information on the mating rituals of jumping spiders visit the Elias Lab.

The hand-drawn animations were photographed at the Brown University Science Center. Thanks also to the Granoff Center for the Creative Arts. Music by scottaltham and Weston Wyse.

CreatureCast- Life on a Lobster Mouth

posted by nchen / on May 9th, 2011 / in Arthropods, lifecycles, Podcast (Student Contribution), Symbiosis

Symbion pandora is a microscopic animal that lives exclusively on the mouth-parts of lobsters. When we think of a life-cycle, we usually think of a baby growing into an adult, a female mating with a male, and then the female giving birth to a baby. But as Symbion pandora demonstrates, this isn’t always the case. Symbion pandora undergoes both asexual and sexual reproduction. Its life cycle is especially interesting because the timing of its sexual reproduction matches the moulting of its lobster host. This allows Symbion pandora to move from the lobster’s old shell to its new one, a remarkable solution to the problem of a temporary home. First described in 1995 by Peter Funch and Reinhardt Kristensen, Symbion pandora’s life-cycle provides insight on the incredible diversity and range in the ways organisms grow and reproduce.

Video and narration by Natividad Chen. The background music is a compilation of Bach’s Cello Suite 1 Prelude and Bach’s Flute Sonata 2, both played by Felipe Sarro.  This podcast is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

CreatureCast – Antarctic Krill Love Dance

posted by Sophia Tintori / on March 7th, 2011 / in Arthropods, lifecycles, Podcast, Science & Art

This is a really nice video that was published in the Journal of Plankton Research this past February, as a part of this article about krill.

Even though krill make up a large fraction of the living mass of the ocean (and are also the food for large charismatic sea mammals), many aspects of their biology is unknown, including the way they reproduce. Recently Dr. Kawaguchi and his colleagues filmed the process happening near the sea floor, which was surprising because krill are notorious for living their lives swimming around up higher in the water, far from the floor.

The footage that the researchers collected was a bit chaotic (above, left), and so they gave it to Lisa Roberts, an animator (and CreatureCast contributor), to illustrate the process. She traced the motions of the crustaceans from the videos, and also practiced the moves with some shrimp from the market (above, right).

The original video footage from the deep sea is also really nice to watch, and can be found here, at the Journal of Plankton Research website.

The animation at the top of the post, and the drawing at the bottom, were made by Lisa Roberts and released under a Creative Commons Attribution Noncommercial Share-Alike 3.0 license. The soundtrack to the animation is by Graeme Ewing.

CreatureCast – The Stomatopod Strike

posted by Sophia Tintori / on December 7th, 2010 / in Arthropods, Biomechanics, Podcast (Student Contribution)

This podcast comes from Nati Chen, a sophomore in Casey Dunn‘s Bio 0410 Invertebrate Zoology class here at Brown University. In this video, Nati describes how this crustacean is able to move its appendages faster than could possibly be accounted for by muscles alone.

All of the artwork and edited was done by Natividad Chen, and many of the sound effects are real recordings of stomatopods, provided graciously by the Patek lab at University of Massachusetts at Amherst. The video is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license.

Know Your New England Bioluminescants

posted by Sophia Tintori / on September 27th, 2010 / in Arthropods, Comb Jellies, Dinoflagellates

Towards the end of the summer the waters around southern Rhode Island get quite sparkly at night. I’ve wondered for a while what exactly the sparkling things might be, but it wasn’t until recently that I remembered to bring a bucket with me and look at its contents in the light of day.

When I went out to the ocean a couple of weeks ago, I noticed three distinct sizes of glowing creatures; the tiny specks that make a cloud when you kick the water, the medium ones that look like a pair of triangles, and the big circular ones, that stay glowing for a second or two.

Steve Haddock, one of our friends at the bioluminesence lab at the Monterey Bay Aquarium Research Insitute, helped characterize some of these organisms. Here’s what I found.

The larger circular ones are comb jellies.

We get a lot of comb jellies called Mnemiopsis around here. By the end of the summer there are sometimes so many that it feels like swimming in a giant bubble tea. This seems to be a very young Mnemiopsis, not quite mature yet. Comb jellies don’t have any stinging cells, and are not technically jellyfish– corals and anemones are more closely related to jellyfish than these creatures are, even though these look similar. For more about the psychedelic rainbow colors pulsing down the side of this animal, check out Brown undergrad Lee Stevens’ podcast on comb jellies.

According to Dr. Steve Haddock, bioluminesence correspondent, the smallest size of glowing thing is most probably a bunch of single celled organisms called dinoflagellates.

The last glowing group I found seems to be these copepods, a type of small crustacean.

The appendages at the very back of their bodies are long and thin, but move back and forth so fast that they look like little paddles. These thin appendages whipping around are probably what looked little triangles underwater.

These videos and photos were taken by Sophia Tintori, and released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license. Thanks to Steve Haddock for his help. If you see jellies in the water, you should let Steve know at Jellywatch.org. Thanks to Mickey Zacchilli for helping with the video. If you enjoy watching the pulsating comb rows of a comb jelly, here is another clip for you.

Jellyfish Capsule Hotel

posted by Sophia Tintori / on September 11th, 2010 / in Arthropods, Jellies, Parasites, Siphonophores

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- Jellyfish Theater

posted by Sophia Tintori / on July 16th, 2010 / in Arthropods, Jellies, Parasites, Podcast, Symbiosis

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.

Centerless Self

posted by Sophia Tintori / on June 15th, 2010 / in Arthropods, Development, Platyhelminthes

The sense that the self exists somewhere close to the brain or heart is an intuitive one for humans. It also seems to apply to most of the animals we regularly encounter, even when they can regrow parts of their body. When a crayfish gets into a tight spot and loses one of its claws, the part of the crayfish with the head will regrow the lost claw, but the claw won’t regrow a body and head.

For many animals, though, there is no such essential center of the organism. When a flatworm gets its tail cut off, both the tail and head will fill in the missing parts and make two whole flatworms that are clones of each other. Its body is arranged such that there isn’t a single part of the animal that can be identified as the core.

Here is a bit of footage taken by Stephanie Spielman, an undergraduate in Casey Dunn and Gary Wessel’s seminar on the evolution of multicellularity at Brown University. The clip features the flatworm Dugesia tigrina swimming around the Dunn lab. It is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license. The crawfish video is from Day at the River (1928), a video from DeVry School Films, Inc., which is under public domain.