No Bones

Metal Medusae: Trace elements in the upside-down jellyfish Cassiopea

What comes to mind when you think of a jellyfish?  Stings?  Tentacles?  SpongeBob SquarePants with his net?  I like all of these answers, but after coming across some scientific studies, I’d add the elements copper, zinc, chromium, arsenic, and iron to the list.

Cassiopea are unique in their upside-down lifestyle. This is an upward view from under the soft mesh we use as a barrier between our delicate jellies and the intake of the water filter.

Researchers in Australia have discovered that the upside-down jellyfish can accumulate trace amounts of these METALS in its bell and oral arms, and these amounts exceed those in the surrounding seawater (Templeman & Kingsford, 2010).  The specific elements measured in their study were aluminum, arsenic, barium, cadmium, chromium, copper, iron, manganese, and zinc.  But if you’re now envisioning the ocean as a liquid wasteland, rife with old power wires and discarded toasters, be sure to read ahead before you cancel your next beach vacation.

Some beautiful shots of our AquaRoom inhabitants.

Some of these metals are actually ESSENTIAL TO LIFE: copper is in hemocyanin, the oxygen-delivery protein used by multiple invertebrates such as horseshoe crabs, octopuses, squids, lobsters, shrimps, and snails; iron facilitates oxygen transport in hemoglobin, the oxygen-delivery protein of vertebrates (like us!); chromium helps regulate our sugar levels; DNA function requires zinc; and manganese is present in our bones.  But as with many good things, too much = bad.  And although a good general principle is arsenic = bad, minute quantities of this notorious element may even be essential, too (Hunter 2008).

A section of the periodic table of the elements (Patti 2006), with the nine elements found in Cassiopea outlined in purple.

With such a delicate threshold between essential concentrations and harmful ones, keeping a sharp eye on these levels is quite important.  This is where the term BIOMONITOR comes into play.  Also known as a bioindicator or indicator species, this is an organism that can provide useful information about the surrounding environment.

Jellyfish have often been overlooked for this role.  To be an effective biomonitor, species should have a wide geographic distribution, be relatively sedentary, tolerant of physicochemical (physical/chemical) changes, be readily identifiable, and be able to accumulate elements of interest (Templeman & Kingsford, 2010).  But Cassiopea are unlike most jellyfish in these respects: in addition to their expansive coastal marine environments, Cassiopea ARE relatively sedentary (they hang out upside-down on the ocean floor), and this trait also makes identification easy; they are EURYHALINE (your word of the day, meaning they can tolerate water of varying saltiness); and from the studies, it’s evident they can retain metals that have significant importance to life (Templeman & Kingsford, 2010).

This aerial shot demonstrates how Cassiopea are easily identified.

But why not just sample the water itself?  Why is a biomonitor so important?  While directly measuring contaminants in the water can be helpful, getting this information from a living creature provides much more relevant data in terms of how these contaminants affect the organisms and their ecosystem (Epstein et al. 2016).  What’s more, these metals can accumulate as they are passed up the food chain, posing potential risks to larger predators and, eventually, us!  This accumulation is not apparent when only sampling the water.

And one more very cool thing: researchers were able to use a jellyfish’s metal composition to determine where it came from  (Templeman & Kingsford, 2010)!  The animals were collected from one of five locations in Australia, ranging from the continent’s north coast to its east coast, which is about 1700 miles (2700 kilometers)!  For any fans of forensic science shows, this reminded me of investigators tracking where an item was purchased based on its UPC code, or where soil found at a crime scene could have originated.  Perhaps someday soon a jellyfish will be entered as a piece of evidence because of what metals are found in its bell.

Who knew jellyfish were such metalheads?

By Daniel Jackson

References

Epstein, H. E., Templeman, M. A., & Kingsford, M. J. (2016). Fine-scale detection of pollutants by a benthic marine jellyfish. Marine Pollution Bulletin, 107, 340-346. http://dx.doi.org/10.1016/j.marpolbul.2016.03.027

Hunter, P. (2008). A toxic brew we cannot live without. Micronutrients give insights into the interplay between geochemistry and evolutionary biology. EMBO Reports, 9(1), 15–18. http://doi.org/10.1038/sj.embor.7401148

Patti, S. (2016). Period Table of Elements [Open-source computer software]. Retrieved from https://sourceforge.net/projects/periodic-table-of-elements-qt/

Templeman, M. A., & Kingsford, M. J. (2010). Trace element accumulation in Cassiopea sp. (Scyphozoa) from urban marine environments in Australia. Marine Environmental Research, 69, 63-72. Doi:10.1016/j.marenvres.2009.08.001

 

 

 

 

Creatures from another world right under your nose

The vast world of invertebrates encompasses some truly beautiful and bizarre creatures, animals so exotic-looking that you’d only expect to encounter them in the deep regions of underwater realms.  But many would be surprised to know that the National Museum of Natural History houses LIVING jellyfish in the 2^nd-story region of its terrestrial Invertebrate Zoology department.

These animals do not mind living amongst the webs of algae, and their hardiness make them ideal creatures to care for and study.

That’s correct—within the labyrinth of hallways and staff offices, nestled amongst the specimen collections and laboratory space, there exists the AquaRoom.  Inside, dozens of jellyfish reside in a series of aquariums, the largest of which holds 55 gallons of saltwater (mixed by hand with Instant Ocean salt, deionized water, and intern elbow grease).  And by far the most bountiful of our lovely lifeforms belong to the genus Cassiopea, commonly referred to as the upside-down jellyfish.

While called the upside-down jellyfish, these animals do not always remain so oriented. Here we see one individual breaking from the norm as it hovers over its fellows like a mothership.

Cultures of Cassiopea jellyfish are relatively easy to maintain and propagate.  Personally, the only prior experience I had with aquariums was owning a few kinds of pet-store fish, but fellow intern Christine Martin and I have succeeded in caring for these magnificent animals over the last year, allowing them to grow in size and reproduce.  Regarding size, these animals are typically 1/16-1/8 of an inch (.16-.32 cm) in diameter when they start swimming around as babies; however, our largest jellyfish currently has a diameter of around 5 inches, or 12.7 cm (a conservative estimate).  This means some of the baby jellyfish we received in 2014 have increased 40- to 80-fold in size since the AquaRoom started regularly keeping marine invertebrates!

Some of our largest Cassiopea; the jellyfish on the right is approximately 5 inches across! This is an aerial view, making it easy to see why these are called upside-down jellyfish.

And Cassiopea are not the only aquatic occupants lurking in our AquaRoom, either.  We also maintain cultures of box jellyfish (class Cubozoa), care for an impressive octocoral (class Anthozoa), and look after several other Cnidarians that we periodically receive from institutions such as the National Aquarium, although these species usually require more intensive care than our upside-down jellyfish.  Currently the primary jelly care-taking reigns have been handed over to Christine, and she would definitely be the best person to speak with if you’d ever want to take the AquaRoom tour!

One of the AquaRoom’s other inhabitants: a box jellyfish (Class Cubozoa). This shows the stages of development as the polyp (upper left) metamorphoses into a juvenile jellyfish (bottom left). You can see how earlier the remarkable eye (with lenses, etc.) of the adult jellyfish develops early during the polyp metamorphosis (upper right). 

Observing these jellyfish in person borders on indescribable, but I will try anyway.  It is strange to develop such a level of respect and awe for a faceless invertebrate animal, not to mention one that lives in water while also being 95% composed of it.  Part of this connection may be a result of feeding and caring for them for months, but I believe the feeling has deeper roots.  To be face-to-face with a being so blatantly different and strange while knowing, consciously or otherwise, that they successfully and comfortably share the same world we do—that is a mind-bender.  If you are ever annoyed, saddened, or just bored by day-to-day life, maybe spend an afternoon with our jellyfish: it’s like visiting another planet, but without running out of oxygen, or getting too close to the Sun, or getting too far from the Sun, or crashing into an asteroid, or absorbing too much gamma radiation, or…you get it.

Another AquaRoom dweller, our lovely octocoral (Class Anthozoa, Subclass Octocorallia). At one point, one of this coral’s arms was knocked off, so we actually have an additional (albeit much smaller) coral that is doing just fine on its own!

In other words, there is a hidden dimension, beyond that which is known to the average Smithsonian museum visitor.  It is a dimension as vast as a small office and as timeless as 2014.  It is the middle ground between ocean and knowledge, between science and education, and it lies between the exhibit of Human Origins and the summit of the museum’s 3^rd floor.  This is the dimension of fascination.  It is an area which we call the AquaRoom.

 

By Daniel Jackson, IZ Intern

 

 

Stinging Snot at the Smithsonian

If you have ever been snorkeling in Florida or the Caribbean, or pretty much any warm shallow tropical or subtropical water, you may have been lucky enough to see the charming and eccentric upside-down jellyfish (Cassiopea spp.). Unlike most jellies, these animals sit bell-side down on the sandy or rocky bottom and raise their oral arms into the water column. Cassiopea have a symbiotic relationship with microscopic algae called Symbiodinium, which typically live within the tissues of the animal. This symbiotic relationship allows Cassiopea to get the majority of its energy and nutrition from the sun, but they retain their ability to capture prey using stinging cells, called nematocytes, which are found within all cnidarians (jellies, sea anemones, corals, hydra, etc). Their sting is fairly mild to moderate for humans, but can be painful depending on various environmental factors yet to be established.

Cassiopea medusa with white-tinted “snot” surrounding the bell.

For instance, if you have been a less than fortunate snorkeler, you may know you don’t need to touch these adorable jellies to feel their sting. Through a phenomenon known as “stinging water,” Cassiopea jellies release mucus full of stinging cells into the water column.

Brine shrimp (red arrows) stuck in mucus of Cassiopea.

Despite the unusual, indirect sting mechanism noted by frequent mangrove snorkelers, there is no formal description of the stinging contents of this mucus or the ecological role it might play. This raises numerous interesting questions about this unique behavior. What types of stinging cell types are present in Cassiopea mucus? How concentrated are the stinging cells in the mucus? And how do they get embedded in the snot?

Snot released from Cassiopea. Often the entire dish will be filled with clear mucus after 2-5 minutes of disturbance.

A team of researchers and volunteers in the AquaRoom (wet culture lab) of IZ have been trying to answer these questions over the past few years, and we have discovered something totally unexpected in Cassiopea mucus: strange microscopic structures composed of nematocytes. No information about these odd structures could be found in the current literature, only anecdotal reports noted in tourist guidebooks about stinging water in mangroves, where these jellies are commonly found.  Our initial questions were soon replaced with new ones. What are these structures and what other kinds of cells are they composed of?  What is their function? How are they made? And in terms of stinging power, how potent are they?

For answers to most of these questions, stayed tuned for a scientific publication we are preparing on these novel structures comprising Cassiopea mucus!

What I can share now, however, is a little bit of the analytical techniques I learned during the month of July. I proposed to complete ultrastructural analyses (using various forms of microscopy to determine what cells types and cellular components were present or absent in the mucus) coupled with functional analysis (determine various activities of the stinging components in the mucus) in order to infer how this mucus might be used in the jellies’ environment. For the ultrastructure, I was trained on the epifluorescence scope at the NMNH by Scott Whittaker, manager of the SEM Imaging Lab. Using a newly developed microfluidic device, I could image and observe the contents in a more holistic context, and reduce some of the potential resolution issues inherent in trying to image mucus squashed onto a slide. I could also introduce brine shrimp into these chambers to see how they behaved in the presence of the stinging snot.

Microfluidic device used for microscopic imaging. (Designed by collaborator Krishna Badhiwala in the Robinson Lab at Rice University).

If you go back to the anecdotal reports of Cassiopea stinging mucus, there are two claims that are largely assumed: 1) the mucus contains stinging cells (as opposed to soluble proteases or other toxins) and 2) the mucus appears to be used both in predation and defense. Our findings corroborated that the mucus itself does contain large, penetrant stinging capsules with barbed shafts and long threads. These capsules are called rhopaloids, because they have a distinct, barbed shaft, e.g., birhopaloids have two distillations, or bumps, along the shaft, while euryteles have only one. Rhopaloids range from 8-15 um long, or 8/100ths to 15/100ths of a millimeter.

Penetrant stinging capsule, discharged, 100x.

In the mucus, I often found these cells in groups of 3-4, some discharged, others not. Finding these stinging capsules in both states is important, since it could be argued if all of the stinging cells were in their discharged state, these stinging capsules could simply be ejected from the tissue after being fired. This would mean the stinging of the mucus is an artifact of discarded stinging cells that may release some of the toxic contents instead. Since we also find undischarged capsules seemingly stuck in the released mucus, these capsules have the potential to envenomate prey and predators when encountered some distance from the jellyfish that produced them.

Group of four undischarged capsules, 100x.

It is also interesting to note that I mainly found large penetrant capsules in the mucus, and just a few of the two other types of Cassiopea stinging capsules: O-isorhizas and a-isorhizas. These nematocyst types are generally smaller, do not have a barbed shaft, but are found throughout the tissue of Cassiopea. This may suggest an adaption to releasing these larger stinging cells over the others, but the reasons are not totally clear. Do these larger penetrant cells have different toxins that are absent in the other stinging cell types? The variation in venom profiles of different stinging cell types is another major question I hope to address in future research. For more photos of some of the stinging cells I have been imaging, check out my blog post: Stinging Cells from the Summer.

In all of my excitement, I never introduced myself! That tends to happen when you get me started talking about jellyfish and venoms. My name is Anna Klompen, and in the fall I will begin my second-year as a graduate student in Ecology and Evolutionary Biology at the University of Kansas in Dr. Paulyn Cartwright’s lab. I have been fascinated with jellyfish for almost a decade now, and feel extremely lucky to work with these animals. I am interested in venom evolution and diversity within jellyfish, and the relationship between venom composition, function and the ecological roles these venoms play within the complex life histories of many cnidarians. The start of my jellyfish research career actually began here at the NMNH two years ago as a NOAA Hollings Scholar. It was even in the same lab I am working in now, supervised by Dr. Allen Collins.

Summer of 2016, started working at the NMNH as a NOAA Undergraduate Scholar.

Now as a visiting scholar, I have returned to this project that was started two years ago with several high school interns I worked with in the AquaRoom. I have loved being able to spend my July exploring a new jellyfish system, learning new techniques in microscopy, and working in the museum I loved two years ago.

Summer of 2018, first day after training at the epifluorescence scope as a Visiting Researcher.

This research was completed under a Visiting Researcher Fellowship at the National Museum of Natural History, Smithsonian Institution. The project was funded by the Lerner-Gray Memorial Funding for Marine Science from the American Museum of Natural History and a Graduate Studies Research Support Award from the University of Kansas. A huge thank you to Dr. Cheryl Ames, NRC Postdoctoral Fellow, for the mentorship on this project, as well as Kade Muffet and Mehr Kumar, who began this project as high school interns in 2016. And for all the laughs and jellyfish nerdiness, thank you to everyone in the AquaRoom this summer for making me so happy to be working on these adorable animals!

By Anna Klompen

 

Further Reading:

Berryman, M., & Wood, J. B. (n.d.). Upside-down jellyfish, Cassiopea xamachana. Retrieved from http://www.thecephalopodpage.org/MarineInvertebrateZoology/Cassiopeaxamachana.html

Badhiwala, K. N., Gonzales, D. L., Vercosa, D. G., Avants, B. W., & Robinson, J. T. (2018). Microfluidics for Electrophysiology, Imaging, and Behavioral Analysis of Hydra. Lab on a Chip, http://dx.doi.org/10.1039/c8lc00475g

Collins, A., N., & Ocean Portal Team. (2018, June 01). Jellyfish and Comb Jellies. Retrieved from https://ocean.si.edu/ocean-life/invertebrates/jellyfish-and-comb-jellies

Ohdera, A. H., Abrams, M. J., Ames, C. L., Baker, D. M., Suescún-Bolívar, L. P., Collins, A. G., ... & Jaimes-Becerra, A. (2018). Upside-Down but Headed in the Right Direction: Review of the Highly Versatile Cassiopea xamachana System. Frontiers in Ecology and Evolution, 6, 35. https://doi.org/10.3389/fevo.2018.00035

Östman, C. (2000). A guideline to nematocyst nomenclature and classification, and some notes on the systematic value of nematocysts. Scientia Marina, 64(S1), 31-46. https://doi.org/10.3989/scimar.2000.64s131

Upside-down Jellyfish - Cassiopea - Overview. (n.d.). Retrieved from http://eol.org/pages/23710/overview

3D Scanning in Invertebrate Zoology

Today our 3D team drove to the Smithsonian’s Museum Support Center (MSC) with a car full of 3D scanning equipment. MSC is a collection storage facility that houses objects not on display at the Smithsonian museums. The 3D team’s mission is to scan a group of ancient turtle skeletons and crustaceans; specimens too large or fragile to be easily transported.

Walking through the treasures that live in MSC, it felt like a wild expedition with shelves brimming with fossils ready to be discovered.  

Tim Coffer, a Collections Manager of the Invertebrate Zoology department at the Smithsonian National Museum of Natural History (NMNH), fed our curiosity by giving us an exclusive tour of the other 99% of the Smithsonian collections not on public view.

A few weeks earlier, the 3D team collaborated with Tim on the coral pilot project scanning over 80 coral specimens in two weeks. We use several methods of scanning 3D models of coral: automated turntable photogrammetry, hand-held photogrammetry, and structured light scanning.

In addition to hundreds of mammal skeletons like deer, rams, elephants, there we also saw thousands of jars containing marine creatures. The whole team was fascinated by all the specimens and took turns asking Tim about their origins.

Following the tour, we started to setup our equipment for photogrammetry on the Invertebrate Zoology floor. Later in the week we will be getting down to business.

By Taylor Houlihan, 3D intern for OCIO-DPO

 

Tiny Jewels in the Ocean

In the group of marine animals known as echinoderms (from Greek, meaning “spiny skins”), there are five distinct groups alive today – the familiar starfish, sea urchins (including sand dollars), sea cucumbers, sea lilies, and brittle stars.   A beachcomber picking things up along the shore, or a deep-sea fisherman sorting his catch in a net, can usually tell at a glance to which group of echinoderms a specimen belongs, for the five main groups have fairly distinctive shapes. 

But, not always.

Figure 1. A typical brittle star. From Hendler, G. et al. 1995. Sea stars, sea urchins and allies. Smithsonian press.

 

There are about 2,000 species of brittle stars alive today, and most brittle stars are shaped like this (Figure 1), with a small central disc and five so-called arms.  But, in 1879, a British scientist, Dr. W.P. Sladen, discovered a strange little echinoderm, about half an inch across, that he at first thought was a starfish – it was certainly starfish shaped - but on further study, he was amazed to find that it was a brittle star.  He named this new genus Astrophiura, which might be translated to mean “starfishy brittle star”.  In the intervening 100 years and more, about eight additional species of this strange animal have been found, in various areas of the world’s oceans.  Until recently, though, none had been recorded from the Atlantic Ocean.

A few specimens, some in the collections of the Smithsonian’s Natural History Museum, and others that have been collected very recently in the vicinity of Curacao in the southern Caribbean, have proven to be Atlantic Ocean representatives of this weird starfishy brittle star, and I have named this new species Astrophiura caroleae in honor of Dr. Carole Baldwin, a Curator of Fishes in our museum, who founded DROP (Deep Reef Observation Project) several years ago, and whose dedication and enthusiasm has resulted in many new deep coral reef discoveries being made using a manned submersible, Curasub, which can dive to depths of 1000 feet and more.

Figure 2. From Pawson, D.L. 2018. Zootaxa 4378 (2).

 

Astrophiura caroleae, like its weird relatives, is about half an inch across, with a starfish-like central disc, and tiny fragile so-called free arms, which are usually broken off when individuals are collected.  This animal (Figure 2A, 2C, 2D) is usually easily visible because of its bright reddish color, and it adheres to hard surfaces, so it can be found attached to dead shells, pieces of coral, and man-made objects – such as discarded beer bottles (Figure 2B).

Does this little creature play an important role in the general economy of the deep sea?  Probably not.  It is seldom found, but it always excites interest and pleasure.  A tiny and beautiful jewel that challenges us to learn its secrets!

By Dave Pawson

Volunteers, Interns and Contractors - Can’t Live Without Them!

The Department of Invertebrate Zoology (IZ)-Lab 5 at the Museum Support Center (MSC) is a busy lab year round. Work spaces cluttered with specimens, curation supplies and microscopes are constantly in flux with visiting researchers, graduate students and fellows, as well as volunteers, interns and contractors.

With new collections constantly arriving and others being shipped out to requesting researchers, carts filled with specimens waiting to be processed (curated, labeled, inventoried, packed, etc….) is a common scene. But specimens are not the only items in need of attention: scientific plates and films (negatives, SEM and prints) as well as research documents and publication reprints are in the queue to be scanned, filed and archived.

So many projects, too little time…. That’s where Smithsonian volunteers, interns and contractors come in. They are recruited for many collections-based projects that are advertised via the SI Volunteer Program, SI Internship Program or through departmental contracts. These programs all offer long and short term tenures, and some seasonal positions, depending on the interests of the individual.

The volunteer program at the Smithsonian Institution is tailored towards non-students with a desire to contribute their time and expertise as well as their love of learning. A number of volunteer opportunities are available from research related, to public education programs, and Behind-the-Scenes. Here again, long and short-term positions are offered.

The Smithsonian Institution internship program offers students (graduate, undergraduate and even high school) an opportunity to work directly with a staff member in an academic and professional setting. Students interested in working at the National Museum of Natural History (NMNH) can select a project from the many available at NMNH Internship Opportunities. Winter and spring break (just one week) as well as summer internships are available.

Another way to get involved in the Smithsonian is through a contract. Contracts offered at the Smithsonian provide paid positions for museum professionals, and depending on available funding, there can be a number available at any given time. Here in IZ-Lab 5, contracts offered involve curatorial tasks, specimen inventory and labeling, and document processing/scanning. These positions can vary from a few months to 1.5+ years.

Support from volunteers, interns and contractors is indispensable for the management of our museum collections and research facility. The decrease of permanent staff in IZ-Lab 5 has made the help of volunteers, interns and contractors even more critical to complete many important collections projects. The day to day work in IZ-Lab 5 is positively complemented by their efforts, whether it be assisting with the physical care of the collections, or collecting research data, or entering specimen data for inventory records. Without their help, most of these projects most likely would be delayed for years, or worse, never get done ending up in the “attic”...

 

Highlighted here are a few friendly faces found in IZ-Lab 5 this past summer:

Marshall Boyd – Summer Intern and Volunteer

Marshall was an intern with IZ in the summer of 2009 before traveling to Honduras where he served as a research assistant. He later went on to earn his Masters Degree from Salisbury University studying forest birds on the Eastern Shore of Maryland.

As a volunteer in IZ-Lab 5, Marshall is involved with the crustacea collections and crustacea research-related material. His first project was to scan research publications from Drs. Horton Hobbs, Jr. and Horton Hobbs III. He was then tasked with scanning crustacean specimen catalog cards for upload to EMu (the Smithsonian Institution inventory program). He is also working to label, organize and curate specimens throughout the crustacean collections, including newly acquired specimens.

 

Linda Ward - Volunteer

Linda was a Department of IZ employee for 35 years. She was responsible for cataloging, collection curation, bibliographic work, as well as research assistance and field work for Dr. Kristian Fauchald in Belize, Florida, France, Aldabra and Papua New Guinea. Her education background is a Bachelors of Art and Masters from the University of Hawaii (a longgggg time ago). 

As a volunteer, Linda is currently working on collections from Dr. Fauchald and his students, as well as her own backlog of miscellaneous cataloging and curation. She is also completing datasets for worm catalog records that were created during a card scanning project years ago. Linda is organizing Dr. Fauchald’s papers/files/manuscripts and preparing material to be transferred to the Smithsonian Institution Archives.

 

Paul Greenhall - Volunteer

Paul worked for the Smithsonian Institution for 40 years before retiring in 2014. He has since returned as a volunteer to work in the Department of IZ. He holds a Bachelor of Arts degree from the College of Behavioral & Social Sciences, University of Maryland.

Paul has held a number of positions at the Smithsonian Institution during his tenure, starting as a volunteer then a contractor in primate biology in the Department of Vertebrate Zoology. He later joined IZ working in Mollusks sorting, packing and shipping collections. As the IZ Shipping Manager, he began packing, shipping and preparing CITES permit applications and helped improve trusting diplomatic relationships between FWS-Baltimore and IZ over CITES issues.

As a volunteer in IZ-Lab 5, Paul curated the Land Snail Collection, and then assisted with packing & shipping. And in 2016 he and his successor, Courtney Wickel, prepared the IZ Packing & Shipping Guidelines that covers the “Whys” of packing & shipping and problem-solving.

 

Carmen Williams – Summer Intern and Volunteer

Carmen was a summer intern in IZ-Lab 5 and is currently a volunteer. She assisted with museum curation and various specimen-related projects in IZ. As many universities and organizations from around the globe seek to borrow from the Smithsonian’s vast collection, Carmen learned about shipping different invertebrate groups as she prepared to become certified to pack wet specimens. Carmen also worked on an ongoing shipworm rehydration project where she verified the USNM catalog numbers, and then rehydrated the specimens for proper curation.

Carmen grew up in Baltimore, and she has many fond childhood memories of weekends spent roaming the halls of the NMNH. The museum represented a place of adventure, and she appreciates the opportunity to intern in a place with such a significant link to her personal history.

Her internship provided her with practical application for the techniques and skills she learned at Coastal Carolina University, as well as a chance to connect with and learn from IZ researchers and the collection staff. The most rewarding part of her internship was assisting with organizing and curating a section of the IZ wet collections.

(Carmen was featured as Intern of the Day on June 16, 2017 on the NMNH Interns & Fellows Facebook page.)

 

Amelia Lindsay-Kaufman – Summer Intern

Amelia was a summer intern in IZ-Lab 5. Her internship focused on collections management, concentrating on crustacean specimens. As she studied geology in college at McGill University in Montreal, she had much experience working with rocks, but not as much experience working with invertebrates. With this experience she was able to learn more about how biological specimens are collected, preserved, and organized for future study.

Amelia always loved science and natural history museums, and she aspires to eventually work in a museum. Therefore, she knew she wanted to intern at the Smithsonian Institution, particularly the NMNH, so she would be immersed in science and gain practical experience in a museum setting. The highlight of Amelia’s internship was unpacking a shipment of freshly collected invertebrate samples from Hawaii, as she was able to learn the necessary techniques used for specimen curation.

(Amelia was featured as Intern of the Day on July 17, 2017 on the NMNH Interns & Fellows Facebook page.)

 

Misha Lerner – Summer Intern

Misha worked on organizing the orphioroids collection, and on rebottling the mollusks collection. 

 

Adam Stergis – Spring Break Intern and Contractor

Adam has been curating and cataloging crustaceans for IZ for over two years now. As an undergraduate at the University of Mary Washington, he gained experience in vertebrate zoology testing the genetic effects of herbicides on zebrafish. In his senior year he participated in the Smithsonian Institution spring break internship program curating isopods, which are one of his favorite animals. He then found invertebrates to be a much better fit for him.

Adam's work in IZ involved finding uncataloged specimens within the crustacean collection, adding them to the EMu inventory database, transferring them to archival quality containers, and returning them to the collection in the proper order. Whether it be through his work, the seasonal parties, and most recently as grillmaster for the summer IZ picnic, he has felt so welcomed in IZ-Lab 5 and considers himself very fortunate to work for an institution whose museums he have been visiting since he was two years old.

 

Georgia Tschen – Volunteer and Contractor

Georgia has a Bachelor of Fine Arts degree from the University of Iowa and worked as a graphic designer and Art Director in California and Ohio until moving to Washington, DC in 2012. She first began working in the Department of IZ in 2013 as a volunteer designing various graphic projects and archiving photographs.

Her first contract for IZ was digitizing specimen labels and applying USNM catalogue numbers to uncatalogued hyperiid Amphipod lots.

Since then she’s held a several other contracts in the department: curation and rehousing of the U.S. National Parasite Collection, and working on a few publication projects involving diagraming illustrations and Photoshop image enhancements.

Volunteering at the Smithsonian was a great introduction to the city and the people here, and working in IZ has been extremely rewarding. She’s happy to be a part of it, there's always something new to learn and see.

 

By Rose A. Gulledge, Museum Specialist

Translating an abstract?

Someone made the following comment upon reading the abstract of one of my recently published papers (led by Lucília Souza Miranda): "this claustrum paper just about lost me with its first sentence in the Abstract". It is definitely true that sometimes our scientific papers can be rather esoteric. This is all the more true of an abstract, which is properly meant to be a "retelling" of a paper rather than a summary.

So, let's examine the first sentence of the abstract of the paper in question:

"The claustrum in Cnidaria is a tissue in the gastrovascular cavity delimited by a central layer of mesoglea surrounded by gastrodermis (i.e., gastrodermis-mesoglea-gastrodermis), without communication with epidermis."

In re-reading this sentence, it seems a fair assessment. And indeed, in running the entire abstract through a "Readability Consensus Calculator", the consensus view is pretty clear: VERY DIFFICULT TO READ. Point taken.

So here is an attempt at getting the same information as in our abstract across using alternative language. One caveat: No doubt the language is stereotypical, inaccurate, and/or outdated. I can claim no authenticity for it. But do you get it? Is the alternative more clear than the actual?

Totally gnarly version:

So, like there is this hella cool thing in jellyfish, a piece of gut, yeah? This thing is called claustra and it’s really four different things, each one a claustrum. They grow, like, inside out from walls in the stomach and become totally new walls breaking the stomach into parts. If you zoom in way close, they have jelly-like stuff surrounded by gut tissues on both sides, and they do not connect to the outer skin (your epidermis is showing--jk). And this claustrum's been used to tryna suggest that two different kinds of jellyfishes, the square and hurtful box jellies and the beautifulest stalked ones, are closely related. But it’s totally bogus to accept that box jellies and stalked jellies both have claustra because, like, it's never really been looked at that carefully. But like we did that. Yeah. And the results are whacked. Actually, it’s like hella cool! Only the stalked guys have claustra, and just some of them at that. What some old dudes (gender-neutral) messed up was that box jellies don’t have claustra. They got these holes in their gut, though, near their throat, and that threw the brainiacs off. Cool thing though, stalked jellies also have those holes! I know, right? So, box and stalked jellies don’t share claustra but they do share gut holes. And by the way, it’s just dope to look at a fossil and think you can make out a claustrum in it.

 

And the real deal:

The claustrum in Cnidaria is a tissue in the gastrovascular cavity delimited by a central layer of mesoglea surrounded by gastrodermis (i.e., gastrodermis-mesoglea-gastrodermis), without communication with epidermis. By dividing the gastrovascular cavity, the four claustra provide an additional level of complexity. The presence of claustra in Cubozoa and Staurozoa has been used as evidence supporting a close relationship between these two cnidarian classes. However, the detailed anatomy of the claustrum has never been comparatively analyzed, rendering the evolution of this character among Cnidaria and its homology in Staurozoa and Cubozoa uncertain. This study provides a comparative investigation of the internal anatomy of the claustrum in Staurozoa and Cubozoa, addressing its evolutionary history based on recent phylogenetic hypotheses for Cnidaria. We conclude that the claustrum is a character exclusive to some species of Staurozoa, with a homoplastic evolution in the class, and that the structure called the “claustrum” in Cubozoa corresponds to the valve of gastric ostium, a structure at the base of the manubrium, which is also present in Staurozoa with and without claustrum. Thus, the claustrum cannot be a synapomorphy of a hypothetical clade uniting Staurozoa and Cubozoa, nor can its hypothetical presence in enigmatic fossils be used to support cubozoan affinities.

And since a picture tells a thousand words (much longer than your typical abstract), here is a diagram that compares species of stalked medusa without and with a claustum. We do not know for certain what the function of the claustrum is, but it does provide a space (pr-principal radial pockets, also known as mesogons or main radial pockets) where the gonads can be separated from the rest of the gut.

Comparison of stalked medusa without (left) and with (right) a claustrum (CS), logitudinal section at the perradii. Abbreviations: an-anchor/primary tentacle, mn-manubrium, gp-gastric radial pocket, pe-peduncle, gf-gastric filaments, gd-gonad, pr-principal radial pocket, ar-accessory radial pocket, and CS-claustrum.

 

 And here is what a claustrum looks like in histological transverse section, marked CS:

Histological transverse cross section through a stalked medusa (Staurozoa) that has a claustrum. The claustrum is marked CS. Other abbreviations: gd-gonad, ar-accessory radial pocket, in-infundibulum, and sp-septum.

And here is the bottom line of the paper: Contrary to what has been stated in the past (and repeated by me in some papers), this structure known as a claustrum is not present in box jellyfish (Cubozoa), but is present in some but not all species of stalked jellyfish (Staurozoa). You can read all about in detail in: 

Miranda LS, García-Rodríguez J, Collins AG, Morandini A & AC Marques (2017) Anatomy and evolution of the claustrum: a comparative study in Cubozoa and Staurozoa (Cnidaria) reveals that it is exclusive to some species of Staurozoa. Organisms, Diversity & Evolution. https://doi.org/10.1007/s13127-017-0342-6

Or you can contact any of the authors to request a PDF copy of the paper.

by Allen G. Collins

Oh how you’ve grown! The Life Histories Program at the Smithsonian Marine Station, Fort Pierce, Florida

In 1972, Dr. Mary Rice made a decision that changed how biologists see the Atlantic coast. As the newly appointed director of a small marine station in Fort Pierce, FL, Rice decided to open her doors to the Smithsonian’s scientific community and research fellows, enabling them to expand their work from specimen collections, to in-depth studies of organisms in their natural habitats. At the station, Rice established the Life Histories Program, which tracks the growth and development of marine invertebrates. For Rice, the Smithsonian Marine Station became an ideal place to research these fascinating creatures and the transformations they experience as they grow from egg to adult. 

Mary Rice and Kevin Eckelbarger comparing specimens in the Life Histories lab in 1974, which was located on a barge on the campus of Harbor Branch Oceanographic Institute at the time.

Mary was most interested in sipunculans, or ‘peanut’ worms, a family of marine worms found worldwide from the shore to the deep sea. She studied the reproduction and development of the many sipunculan larval forms, and then compared them to the development of other worms, followed by more distantly related invertebrates. Through her research, Dr. Rice hoped to gain a better understanding of marine invertebrate development as a whole, and the role it plays in their ability to reproduce, disperse and adapt to different environments.

Mixed plankton sample showing a broad diversity and abundance of Gulf Stream animal forms.

Rice continued her research for 36 years, until her retirement in 2002. Eight years later, Michael Boyle arrived at the Smithsonian Marine Station, first to learn directly from Mary’s extensive experience (she was still working even though long retired), and most recently, as a staff scientist to manage the future course of research in the Life Histories Program. Like Rice, Dr. Boyle’s research focuses on the life histories of marine invertebrates, with a special interest in the evolution and development of sipunculans.

The Smithsonian Marine Station at Fort Pierce, Florida, as it looks today.

This research goes well beyond pure scientific curiosity. Throughout their life histories, invertebrates have a huge impact on the ocean ecosystems we rely upon to feed us and sustain our planet. The large animals we harvest are reliant on the tiny plankton as a food source directly or indirectly depending on their feeding strategies. Furthermore, many of the non-motile adult invertebrates, such as corals, oysters and even some worms, actually form reef structures that shield our coastlines from storms and erosion, simultaneously serving as habitats for all sorts of ocean life.

Compilation of photomicrographs of plankton specimens of various types and the mixed plankton tow sample they were collected from.

To gain a better understanding of the many roles marine invertebrates play in the ocean ecosystem, the Smithsonian began its StreamCode project. Inspired and coauthored by Michael Boyle and Karen Osborn, and with the passionate dedication of several Smithsonian scientists from the Department of Invertebrate Zoology (IZ) and NOAA’s National Marine Fisheries Service (NMFS), the StreamCode project is focused on documenting the stunning diversity of microscopic invertebrates in the water column along Florida’s Atlantic coast. With the Smithsonian Marine Station at Fort Pierce as a base of operations, this team of scientists has set out to collect zooplankton from the Florida Current region of the Gulf Stream.

Most of the June 2017 StreamCode participants (left to right): Allen Collins, Ai Nonaka, Chan Lin, Cheryl Ames, Kate Hansen, Michael Boyle, Karen Osborn, Elise Hartil, Will Jaeckle, Ellen Strong, Leann Biancani, Mike Vecchione, Robert Boyd.

With a multipronged approach using high-resolution photography, DNA sequencing of genetic ‘barcodes’, and detailed descriptions of microscopic diversity, marine scientists will begin to obtain a clearer picture of which planktonic invertebrates move with and survive in the Gulf Stream. 

Kate Hansen and Michael Boyle imaging and processing copepods collected during the June 2017 StreamCode expedition.

From the collections made for this study, more detailed life history studies will allow us to investigate the adaptations of these invertebrates to a broad assault of environmental challenges. Following in the footsteps of Dr. Mary Rice, Dr. Boyle’s efforts in the Life Histories Program, along with help from IZ and NMFS scientists, may give us a more detailed understanding of the development and dispersal of meroplanktonic animals as they surf the currents of the world’s open ocean.

Mary Rice and Michael Boyle in the molecular biology laboratory at the Smithsonian Marine Station at Fort Pierce.

 

By Robert Boyd, Department of Invertebrate Zoology Intern and Masters student at American University

Unsung Invertebrates: Stalked Jellyfishes

“Those who dwell among the beauties and mysteries of the earth are never alone or weary of life.” –Rachel Carson, The Sense of Wonder (1965)

Per usual, the words of trailblazing conservationist and marine biologist Rachel Carson are timelessly applicable. In the quote above, as excerpted from her award-winning composition The Sense of Wonder, Carson emphasizes the values rooted in straying away from what is familiar, and instead pursuing the unknown within the natural world.  Such a reflection analogizes the current conservation crisis of under-studied species such as the stalked jellyfishes, due to their inconspicuous identities. As a relatively obscure group in the world of science (until recently), stalked jellyfish populations have been inadvertently excluded from most conservation efforts, as their existence is often overlooked.

The stauromedusa Craterolophus convolvulus, nestled among the algae, by David Fenwick Senior

Belonging to the class Staurozoa, stalked jellyfishes are members of the Cnidaria phylum, specifically residing under the order Stauromedusae. Early in their taxonomic history, stalked jellyfishes caused some confusion as they were first misclassified as relatives of sea cucumbers, only to later be inaccurately associated with sea anemones (possibly because both organisms live attached to the seafloor). The absence of a medusa stage, in addition to the stalked jellyfish’s favored fixed orientation, provoked major deliberation as to its relationship to other cnidarians with free-swimming tendencies.

Using an adhesive basal disc as a holdfast to latch themselves onto boulders and rocky substrates, as well as onto sea grasses and aquatic plants alike, stalked jellyfishes usually inhabit rock pools and shallow tidal zones with environmental conditions that accommodate their sticky situation! Because species of stalked jellyfish maintain a lifelong sessile position, it is vital that the ecosystem in which they are affixed allows for adequate water circulation to regularly propel food sources into the jellyfishes’ reach. Equipped with nematocysts (stinging cells) stored within the cnidocytes of the tentacles located atop each of their eight “arms”, stalked jellyfishes fire these toxic darts to impair their prey, allowing them time to capture the stunned organism with their tentacles.                                                                  

Lucernaria sainthilairei on the rocks, by Alexander Semenov.

Despite the information collected thus far regarding the behavioral tendencies, anatomical structures, and ecological roles of stalked jellyfishes, the species still remain relatively unexplored. Yet in recent years, scientists have been working in a race against time to properly research individual species, providing scientific names and descriptions of “new” species (they aren’t really new, just new to science!) that lack a proper identity, prior to and in prevention of their untimely extinction. In fact, bringing these poorly known species into the scientific spotlight may be key to their conservation in an ever-changing environment under the pressures of human activities. Without exposure to the attention elicited by extensive research efforts, many species reside in an out of sight, out of mind void where no conservation efforts are made to protect them, solely due to their unsung status. In fact, no species of stalked jellyfish has ever been evaluated to determine if it is threatened or endangered [but see the exciting efforts being made by Stauromedusae UK].

While most stauromedusae are found in cold waters, a few such as this Calvadosia sp. are found in tropical waters. This animal was documented as part of the Moorea Biocode Project in French Polynesia.

As for knowledge about stalked jellyfish biodiversity, Dr. Lucília S. Miranda from the University of São Paulo in Brazil, has made monumental contributions and revisions to the pre-existing understanding of the species in a set of newly published papers. With help from her collaborators, whom she accredits for “assisting [her] with data collections, enriching [her] discussions, and moving [her] forward in [her] research”, Lucília discusses the stalked jellyfish’s nomenclatural history, while underscoring an overall need for further analysis and documentation of all things Stauromedusae. Initially compelled by the cnidarian life cycle, Lucília chose to further delve into staurozon biology through an extensive study of stalked jellyfishes for her PhD (part of which was spent as a visiting researcher in the NMNH Department of Invertebrate Zoology), in which she progressively developed interests in areas including the systematics, evolution, and macroecology (the study of the relationships between organisms and their environments) of stalked jellies. With a scarce selection of background information available, the ambiguous nature of such an under-studied species posed obstacles in her research at times, yet Lucília remains grateful for the challenges presented in her work.

Manania uchidai from Hokkaido Japan.

Some of the earliest records of Stauromedusae research (even dating back to more than 100 years ago) contain anecdotal reports of stalked jellyfish populations disappearing from where they were once abundant, possibly due to pollution. Despite such speculations, stalked jellyfishes have never been studied well enough to fully determine how sensitive they are to pollution or other environmental changes, putting them into a precarious position. Who would have thought that simply living off the grid could potentially be so detrimental to a group of species? However, because every species fulfills a unique role in their surrounding ecosystems, identifying anonymous organisms and extracting further information through research initiatives are fundamental steps in piecing together an ultimate understanding of how Earth’s systems sustain life.  

By Meredith Kucik, NMNH Intern

 

Further Reading

Miranda LS, Mills CE, Hirano YM,  Collins AG, & AC Marques. 2017. A review of the global diversity and natural history of stalked jellyfishes (Cnidaria, Staurozoa). Marine Biodiversity. doi:10.1007/s12526-017-0721-4

Westlake H. E., Page L. R. (2016). Muscle and nerve net organization in stalked jellyfish (Medusozoa: Staurozoa). J. Morphol. 278, 29–49. 10.1002/jmor.20617

 

Miranda LS, Branch GM, Collins AG, Hirano YM, AC Marques & CL Griffiths. 2016. Stalked jellyfishes (Cnidaria: Staurozoa) of South Africa, with the description of Calvadosia lewisi sp. nov. Zootaxa 4227 (3): 369–389. doi:10.11646/zootaxa.4227.3.5 

 

Miranda LS, Collins AG, Hirano YM, Mills CE & AC Marques. 2016. Comparative internal anatomy of Staurozoa (Cnidaria), with functional and evolutionary inferences. PeerJ. 4:e2594. doi:10.7717/peerj.2594

 

Miranda LS, Hirano YM, Mills CE, Falconer A, Fenwick D, Marques AC & AG Collins. 2016. Systematics of stalked jellyfishes (Cnidaria: Staurozoa). PeerJ. 4:e1951. doi:10.7717/peerj.1951   

 

Miranda LS & AC Marques. 2016. Hidden impacts of the Samarco mining waste dam collapse to Brazilian marine fauna - an example from the staurozoans (Cnidaria). Biota Neotropica. doi:10.1590/1676-0611-BN-2016-0169

 

Collins AG. 2014. Knowing a body well: On the importance of studying the histology of stalked jellyfish. 

A strange squid appears even stranger IRL

For readers over 30 years old, IRL means "in real life".

Combfin squids in the family Chtenopterygidae are small, muscular, midwater squids that occupy tropical to subtropical waters probably at depths of 500-1000m during the day and near-surface waters at night. The posterior end of the mantle is broadly rounded. The fins are peculiar: they consist of muscular pillars called fin ribs, connected by thin membranes. The membranes are often torn in captured specimens, giving the fin the appearance of a comb; hence the family name. The fin extends nearly the full length of the mantle.

Every time I have caught Chtenopteryx they have been pretty beaten up. A few years ago, when E/V (Exploration Vessel) Nautilus was conducting ROV operations on Thessaloniki Mud Volcano in the Mediterranean, they recorded video of "a small squid" swimming near the ocean floor at about 1300 m. I finally got to see it recently and it was, as far as I know, the first in-situ observation of Chtenopteryx, probably C. sicula. As you can see from the frame grabs on the Tree of Life and the Nautilus Live video below, this strange squid looks even weirder when it is alive. 

When first encountered, chromatophores (tiny pigment sacs) were expanded over the fin ribs, emphasizing these unusual structures. On the dorsal mantle above the digestive gland was a dark oval patch. Also, patterns of chromatophores on the lateral arms are displayed and then fade. The display of these patterns was surprising to cephalopod biologists and the purpose of the displays is unknown. Seeing it near bottom may seem unusual for a midwater squid, but it may just be at the deepest part of its daily vertical migration.

by Mike Vecchione