Staff spotlight – Jacqualyn Halmbacher

Jacqualyn Halmbacher, Research Associate at The Columbus Zoo and Aquarium Freshwater Mussel Conservation and Research Center, gave us an inside look on her research regarding freshwater mussels for this month’s staff spotlight.

Hilary: “Tell us about yourself!”

Jacqualyn: “I graduated from Ohio University in 2012 with a degree in Freshwater, Marine, and Environmental Biology. After I graduated, I worked in a seasonal position at the Columbus Zoo for five months, before eventually being hired by The Ohio State University as a Research Assistant in  2012. Since 2016 I have been a Research Associate at the Freshwater Mussel Conservation and Research Center.”

Hilary: “What is a freshwater mussel?”

Jacqualyn: “Freshwater mussels are mollusks that are similar to their cousins, clams and oysters.  Mussels are bivalves, meaning that they have two shells that are held together by two adductor muscles and they feed by filtering food such as zooplankton, detritus, algae, and bacteria from the water with their gills. Mussels are an ancient species, actually being traced back to the Triassic Period – 250 million years ago! They’re found on every continent except Antarctica and one third of the world’s mussels are found in North America, with about 80 species of mussels in Ohio alone – with more species found in Little Darby Creek than all of Australian and European species combined!”

Hilary: “Can you tell us more about the facility?”

Jacqualyn: “The Columbus Zoo and Aquarium Freshwater Mussel Conservation and Research Center is a research and educational facility that’s dedicated to freshwater mussels and other freshwater organisms. Animals we house in this facility are for research purposes and will be sent back to the river systems that they came from. Some stay here long-term. Also, another large portion of the animals housed in this facility are for host work, which is important in propagation and knowing where the reared mussels should be released.”

Hilary: “How does the life cycle of a mussel work?”

Jacqualyn: “Freshwater mussels have a unique life cycle that includes a larval stage where they parasitize a fish. Once a female mussel’s eggs have been fertilized, they develop into larvae called glochidia, which will attach and develop on the gills of fish once the female mussel releases them into the water. They will remain on the gills of fish for up to two weeks, where they will receive the nutrients necessary to grow and develop as they metamorphose into juveniles. Once the full transformation is complete, they will leave the host to live independent lives. What I’m doing in my current research with in vitro is simulating the conditions that the glochidia experience when they are on a host fish.”


Hilary: “Propagation? Can you tell us more about this?”

Jacqualyn: “We propagate species naturally by using host fish, but recently we have been working on propagating them artificially in vitro. Freshwater in vitro is accomplished using cell culture techniques, which is removing cells or tissues from an animal or plant and placing them in an artificial environment for survival. The requirements for mussel survival include an environment with controlled temperature, maintaining a particular pH, osmolality, and a growth medium. The culture medium is generally composed of amino acids, vitamins, glucose, salts, proteins, hormones, growth factors, and antibiotics.”


Hilary: “Why is this important to study?”

Jacqualyn: “It gives us the ability to produce more juveniles in one dish than what we could get from several fish, while simultaneously allowing us to see mussel growth and development. Overall, studying mussel growth and development allows us to create successful conditions for breeding and conservation efforts for mussels, which in turn also helps us better protect their freshwater environment. 70% of mussel species are endangered and 37 species of mussels are extinct. Such species loss may have cascading effects through entire stream food webs, so the research we’re undertaking is important to protecting entire stream ecosystems.”

Hilary: “What projects are you working on now?”

Jacqualyn: “We have a propagation project going on in Illinois in conjunction with BP to propagate and release federal and state endangered species in the Kankakee River. I’m also trying to improve mussel rearing methods.”

Hilary: “What’s your favorite part about working at the facility?”

Jacqualyn: “The challenges that the research presents. There is constantly a new problem that needs to be solved in order to move forward. And I love the new microscope we have! I’ve been able to focus on details that you would never even realize were there.”

Hilary: “Have you made any recent discoveries?”

Jacqualyn: A personal accomplishment of mine is using in vitro to propagate mussels. I know that other researchers have been successful with it, but one thing that I’ve learned is that reading a research paper about an experiment and actually trying to duplicate it is something completely different. There are just so many components involved and so many things that happen that you just don’t account for until you’re in the middle of it.

poster - Meet Dr. Tom Watters: mussel man

If you want to learn more about freshwater mussels in Ohio and how to identify them, consider attending one of the mussel ID workshops regularly held at the Museum of Biological Diversity. Please contact Tom Watters, curator of mollusks, directly.


Hilary HirtleAbout the Author: Hilary Hirtle is the Faculty Affairs Coordinator at the OSU Department of Family Medicine; her interest in natural history brings her to the museum to interview faculty and staff and use her creative writing skills to report about her experiences.

Our big day is tomorrow

Tomorrow, Saturday April 22, from 10 AM – 4 PM we will open our doors and welcome all of you to visit our hidden treasures in the natural history collections of The Ohio State University. Stop by and talk to the curators who meticulously keep these specimens and make them available to students and researchers for study throughout the year. This is your chance each year to see what we do and to support our efforts.

The event is FREE and so is parking. We will have many activities for children including face painting, the very popular bugs-in-goo, a live arthropod zoo … and this year new, for anyone over 15 years, guided sessions on scientific illustration, drawing natural history specimens.

Enjoy some photos from last year events

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The set-up for tomorrow is in full swing, here is what I have seen so far

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About the Author: Angelika Nelson is curator of the Borror Laboratory of Bioacoustics and coordinates social media and outreach at the museum.

*** We hope to see you tomorrow ***

Everyday Life at the Museum-part2

Following Monday’s post, here are some illustrations of everyday life in the rest of our collections:

In the Adams lab ants are busy tending their fungi gardens. No students are working the day I stop by, but Rachelle Adams, Assistant Professor in the department of Evolution, Ecology & Organismal Biology, is happy to take a break from her computer work and she shows me the ant colonies in her lab.

In the Herbarium long-time volunteer Donna Schenk relabels some of the folders that hold the plant specimens. Taxonomy is not static, molecular studies reveal new relationships and classifications are revised. To keep the collection up-to-date and to make it easy to find each specimen we need to keep up with these changes.

In the mollusc collection I find Collection Manager Caitlin Byrne working on the computer. Student worker Trevor Smoot sorts through a bag of mussel shells which a researcher donated to the collection. With a big smile Trevor lays out the shells on top of the cabinets, apparently these are some his favorite species. Others will be identified and catalogued later.

In the fish collection Sampling Coordinator Brian Zimmerman and Assistant Curator Marc Kibbey both work on their computers.

Zoology major Elijah Williams catalogs fish specimens from a recent acquisition:


About the Author: Angelika Nelson is curator of the Borror Laboratory of Bioacoustics and the museum’s social media and outreach manager.

*** Do you have any questions? We would be happy to answer them ***

Happy Holidays from the Mollusc collection

… and the giant clam, festively decorated for the Holidays.

Caitlin Byrne, collections manager, next to the giant clam

Caitlin Byrne, collections manager, next to the giant clam Tridacna gigas, one of over 98,000 specimens of molluscs at the museum

Below are a couple of photos from a quick visit to the mollusc collection. Note in the foreground in the picture on the left the book “The Freshwater Mussels of Ohio” authored by by G. Thomas Watters, Michael A. Hoggarth, and David H. Stansbery, a unique gift idea for the Holiday season. In addition to detailed accounts of each mussel species found in Ohio, the book provides information on basic biology, human use, and conservation issues of molluscs. Did you know that a recent scientific estimate puts two-thirds of our freshwater mussels at risk of going extinct? Mussels are important though, they naturally filter the water of our rivers, without them the murky waters would be less livable for other organisms.


About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics and the social media manager for the Museum of Biological Diversity. All photos taken by the author.

Historical record of our museum documented by Carol Stein

Once upon a time there was an amazing naturalist by the name of Carol B. Stein. She was a remarkable woman whose accomplishments were too numerous to be outlined in a single blog post. We’ll be sharing more about Dr. Stein in future posts, from images of her admirable field journals to an explanation of how she began to digitize the freshwater mussel collection LONG before anyone else even recognized that it would become standard… but that story isn’t quite ready for mass perusal.
Today, instead, we’re going to learn a little bit about the history of the Museum of Biological Diversity from a scrapbook gifted to us by Dr. Stein upon her passing in 2010. She put together a binder in 1970 and filled it with a historical record of the museum as it existed at the time. I’ve included a somewhat amended version of it here.
Back then the collections, now housed at 1315 Kinnear Rd, were in the basement of Sullivant Hall, now home to the Billy Ireland Cartoon Library & Museum.
Carol Stein’s original document focused on showing panoramic views of every storage area and office of the museum and was a bit too mollusc-centric to be interesting viewing for our non-malacologist readers. I’ve attempted to highlight any images of the storage areas that are artistically beautiful photographs or those that describe the nature of the inner workings of the museum at the time of the photos.
This post and the following one on Friday are going to be an exploration of the inside of a museum 46 years ago. There are many parts that are shockingly similar to what you can see today such as the constant challenge of space management and the barely tempered chaotic nature of collecting. Of particular interest, the more disparate aspects of then and now, visible in images showing the old public exhibits at the museum. The bird display is quite ambitious, well-executed, and rather terrible for the specimens. Now those specimens live primarily in drawers, protected from the more preventable ravages of time.
One of the bird specimen displays

One of the bird specimen displays

These images tell the story of one of most challenging aspects of a museum: Maintaining an ever-shifting balance between accessibility and preservation. In order for a collection to seem inviting and available to museum patrons it must be regularly (or even constantly) subjected to the evils of dust, light, and air. For biological specimens this leads to rapid deterioration. The solution of course, is to have all specimens sealed away at all times. Unfortunately a complete and utter lack of visible collections makes for an uninspiring and less-than-educational museum experience. The struggle, then, lies in determining a happy medium between a museum’s archival role and its role as a public resource. It’s no small task, especially when paired with a chronic shortage of time, money, and space.
First, below, a look at the operations-side of a museum. On Friday look forward to images of the exhibits no longer present in modern iterations of the museum.

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sara-klipsAbout the Author: Sara Klips, the mussel fairy, still acting as historian.

Artifacts of Our Curiosity

Sometimes there are small treasures that show up on shelves of the museum that we can’t add to the collection, but feel like must be preserved. This is one of those treasures.

This darling package must have been donated a long time ago because no one currently working in the Mollusc range remembers who or where it came from. Apparently Things of Science were small boxes you could order in the 1950’s/1960’s with information and experiments covering a range of subjects. We’ve scanned up the little book and uploaded a photo of the shells that were included in the kit. Enjoy!


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About the Author: Sara Klips is the Mussel Fairy discovering artifacts in the mollusc collection.

Freshwater Mussels Vs. The World

Did learning the difference between the lifestyle of the freshwater vs. saltwater mussels whet your appetite? Are you curious whose cousin you are consuming when slurping scallops or opening oysters?  Do you catch yourself wondering at night if sea slugs are really related to land slugs? Is your superpower talking to octopuses and you want to know what other animals you may be able to communicate with? We have got you covered.

This time, we are going to discuss the relationships between all these molluscs, so you can learn just how distinct these organisms really are.  You will finally be able to join the club* of polite pedantic people standing with on the borderlines between clades reminding anyone who will listen that these organisms are distinct! Among our allies are those who pipe up whenever someone calls a spider monkey an ape and folks who visibly wince whenever anyone implies that a spider is a bug. This is the kind of knowledge you can brag about. You’ll never need something to talk about on a date again. Those long thanksgiving dinners with extended family will be a breeze! Shells are easy to carry around as props so you can always be prepared!

*there is no club


(Those of you who already know the difference are also invited to read on but are given explicit permission to feel slightly smug while doing it. It’s a win either way.)

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Detective Work and Rare Collections II


What did the once hidden collections contain?

The Hildreth Collection contained a total of 84 different species of freshwater molluscs, 64 of which were from the Ohio River System, 12 from other river systems, and 8 specimens from other places around the globe such as France.

Shipping label

The original shipping label for the Hildreth and Holden collections as sent to Dr. David H. Stansbery, emeritus Curator of Molluscs, from H.R. Eggleston.

In 1828, Hildreth published his Observations on, and Descriptions of the Shells found in the Waters of the Muskingum River, Little Muskingum and Duck Creek in the vicinity of Marietta in the American Journal of Science Vol. XIV, 1828. In it Hildreth wrote about the abundance and distribution of twenty-six species of the molluscs found in Marietta Ohio. Luckily some of the text clearly references parts of his actual collection, and it was possible to figure out the original shell’s location by comparing the two.

The most interesting part of Hildreth’s 1828 publication is where he wrote about a species called Dysnomia foliata, now known as Epioblasma flexuosa. This particular species, according to the notes and letters he left behind (as well as the many specimens he sent to other collections all over the USA), was relatively abundant. It is now extinct and no one has seen it since around 1900. How did something once so abundant disappear? Maybe someone will eventually figure it out…

How do we know when the specimens were collected?

As Hildreth added specimens to the collection, he recorded the scientific names for each of them. Scientific names often change over time as new taxonomic research is done and new methods become available. Thus a particular scientific name for a species can be used as a time stamp and, in this case, allowed us to estimate a date range for collection.

A tally of dates

One of the papers left behind by Dr. David H. Stansbery regarding his study of the collection. This is his tally of the dates that species names were being used.

When all the names in the Hildreth collection where tallied up by Dr. David H. Stansbery, emeritus Curator of Molluscs, the story became clearer: The absolute most recent name, Quadrula fragosa, was from 1835. It is, therefore, likely that the collection itself ends a few years after that. My best guess, after going through the Marietta College database of his collected correspondence, is that the collection was set aside in 1840. That is the date when his letters stop mentioning shell exchanges and instead start focusing on geological coal surveys. I also found the first mention of a shell exchange in a letter in 1824.  This indicates that, to the best of our current knowledge, the collection was made over a time-span of around 15 years.


The Holden Collection was the smaller collection of the two, made by a Mr. William Holden. It consists of either one or a few collection events from the Ohio River at Marietta in the year 1879. The Holden collection, therefore, constitutes a very rare look at the nature of the Ohio River naiad (freshwater mussel) fauna of that region between the time of Dr. Samuel P. Hildreth (1825-1840) and the time of Dr. Arnold E. Ortmann (1900-1927).

Letter about Collection

A letter from 1977 found among the documentation relating to the collections.

Ortmann, in his monograph on the Naiads of Pennsylvania, lists records of all Ohio River species of Pennsylvania present in the Carnegie Museum, but does not seem aware of the existence of the Holden Collection. This makes sense, if the collection had been sealed up in a wall between that time and WWII when it was finally discovered.

It does certainly look like this collection’s story has been told before, but unfortunately everyone I tried to track down in reference to it has long since passed away.


About the author: Sara Klips is still the Mussel Fairy and wishes more people realized how engaging shell bound mollusks can be. She hopes that you know that the “eye stalks” on slugs are called tentacles, and that you realize that filmy plastics can never be put in the recycling bin.

Detective Work and Historical Collections

One of the big challenges of freshwater natural history is that it is hard to determine what exact animals were present in rivers before modern collections began. Preservation of pristine freshwater environments has been almost impossible as anything upstream affects everything downstream. Our zoological museums are a physical catalogue of the historical wildlife in an area and a guide for where our habitat reconstruction goals should be set.

Physical collections are fragile. It’s easy to lose data somewhere along the line and have the specimens themselves become nothing more than physical curiosities. It’s even easier to have an extensive and meticulous collection fall into the hands of disinterested heirs and be lost to us. Specimens need to be cared for properly to maintain their quality, and the longer it has been since they were collected, the less likely it is that the historical value is maintained. Occasionally these collections are saved via thoughtful preservation by some concerned individual or institution or, much less often, by a fortuitous fluke of storage through a period when, had it been accessible, it might well have been destroyed.

Hildreth Labels

A collection of old labels, now dissociated from their original specimen.

A perfect example of this kind of fortuitous preservation is represented by two collections, The Hildreth and Holden Collections, currently located in our Bivalve Collection. These two collections were discovered together at Marietta College, Ohio. Few details exist today regarding the exact discovery, but some information has been preserved. Everyone directly involved with the discovery has, as far as I can tell, passed away long ago without publishing the details of the find.

It’s a weird twisting tale and, I believe, it deserves to be informally recorded here.

Our next post will fully detail the relevance of this collection and its history, but for now let’s just set the scene…

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Sucker Bridgework

Comparative anatomies of skeletons stored at the OSU Museum Fish Division can be studied to reveal information on the sort of ecological niches a particular species occupies.  One example is the feeding niche that various sucker fish species exploit.  Based on structures of their throat teeth and the type of prey items retrieved from their digestive tract it would appear that buffalo and carpsucker species use their fine, comblike teeth for sieving their prey, while suckers with larger teeth (most redhorses, hogsuckers, spotted suckers) are said to “masticate” their soft prey, and finally those with the sturdiest teeth are able to shatter the hard shells of molluscs.

The photo below shows the anterior portion of a Silver Redhorse skeleton (OSUM 101341), with an arrow pointing to the pharyngeal tooth arch (position indicted by arrow) located at the rear of the gill basket.


There are  16 extant species of sucker fishes in Ohio’s waters.  Images of four of those species with pharyngeal tooth arches removed from some of our skeletons are shown below.

Spotted Sucker1 from Wolf Creek (Kankakee River) IN 07 01 07 by BZ

Spotted Sucker, Minytrema Melanops.  Photo by Brian Zimmerman.


The Spotted Sucker has been reported to feed on organic fragments, diatoms, copepods, cladocerans, and midge larvae.


Smallmouth Buffalo, Ictiobus bubalus.


Smallmouth Buffalo suckers with their relatively delicate teeth feed on diatoms, dipteran larvae, copepods, cladocerans, ostracods, bryozoans, and incidental algae attached to bottom substrates.


Shorthead Redhorse, Moxostoma macrolepidotum.  Photo by Ben Cantrell.


Shorthead Redhorse stomach contents have revealed their diet to consist primarily of midge, mayfly and caddisfly larvae.

River Rehorse from the Duck River at Shelbyville TN by Uland Thomas

River Redhorse Moxostoma carinatum.  Photo by Uland Thomas.


The River Redhorse has the sturdiest teeth of the four sucker species’ teeth shown here, so much so that they are capable of cracking the shells of bivalve molluscs and snails.

For comparison, inserted below is a photo of the molariform pharyngeal teeth from a Freshwater Drum.  The drum is primarily a carnivore, its diet comprised more extensively of bivalve mollusc and gastropod shells, while the omnivorous sucker fishes find most of their food by grazing the bottom of streams and lakes, sifting sand and gravel to find their little morsels.

drum pharyngeals downsized


About the Author: Marc Kibbey is Assistant Curator of the OSUM Fish Division.