Conserving the Collections

The extensive scientific collections of the Delaware Museum of Nature and Science are utilized by scientists and researchers all around the world. As catalog databases of the collections and their inventories are constantly being built and updated, they are also made more accessible. Increased use of these collections needs to be balanced with conservation efforts to ensure they exist for future generations. Unfortunately, some materials used to store specimens have become outdated and require replacement to best preserve the museum’s collections.

Rows of metal cabinets house the mollusk and bird collections at the Delaware Museum of Nature and Science.

Current Conservation Methods

In the mollusks collection, specimens are preserved either as the dry animal-made shell, or as the entire body and soft parts of the animal in alcohol. The bird collection specimens are preserved as study skins (a specialized taxidermy for research), but also have preserved tissue samples in alcohol, spread wings, skeletons, and traditional taxidermy.

Currently, the collection is stored in specimen trays that are made of paste board wrapped in paper. Depending on their age, some trays may or may not be made out of archival quality material. However, new archival boxes can still endure changes in chemistry when they come into contact with wooden drawers that exist in many cabinets. These wooden drawers could release harmful acid vapors and change the chemical composition of the storage materials. When these materials touch specimens they can cause the chemicals to breakdown, recrystallize, and destroy the specimens, according to Alex Kittle, Senior Collections Manager of Mollusks.

Archival boxes are often laid with unbuffered paper to help protect specimens
Mollusks in archival boxes are stored in trays
Yellowing spots on this shell indicate Byne’s disease, a decay of calcium carbonate and acidic vapor.
Toucans and hornbills stored with unbuffered paper
Fuzzy coating on the left egg indicates decay from Byne’s disease
Fuzzy coating on the egg indicates decay from Byne’s Disease
Damage to these butterflies are indicative of pests

Plans for Improvements

Improvements needed to the collections have been addressed. The collections would benefit from plastic boxes made of a stable plastic and more archival specimen trays. There are regular updates to materials that contain specimens, but there can only be so much done each year. Changing the cabinets the specimens are currently housed in could also prevent any concern of pest damage, and make a world of difference in improving long term conservation. Fortunately, all of the study skin collections are already in new cabinets with metal drawers and archival materials.

Conservation of data is another important concern of collections management. In certain bird species with a fatty diet, oil can seep onto identification tags, remove ink, and make them impossible to read. Additionally, beetles and other pests will feed on organic materials like feathers and introduce harmful microorganisms to specimens. Having up-to-date powder-coated steel cabinetry with a total seal to keep pests from the collections is vital for conservation, according to Ashley Kempken, Collections Manager of Birds. The collections team has also implemented a freezer treatment protocol to kill potential pests on collections objects after they have been used by researchers or in exhibits.

Natural acidity and chemicals can also impact the conservation of specimens. Correct storage of specimens requires using the appropriate archival containers, as chemical reactions from storage materials can easily damage collections over time. Researchers can use methods such as a pH pen to spot check acidity in materials that hold specimens.

Vouchering for Science

A voucher is a specimen that is permanently kept and maintained in a collection and serves as evidence of a species present at a place and time. A voucher can be thought of as a scientific receipt documenting that an organism was found at a particular location on a particular date. Voucher specimens are most often used to verify identifications, but also serve as an invaluable resource for other scientific studies.

Voucher your specimens with us!

Our collections provide a baseline of biodiversity for research projects. Vouchering physical specimens into permanent and managed collections like those at the Delaware Museum of Nature and Science ensures a proper documentation of biodiversity and consistency of research.

To voucher a specimen at the museum, please contact the Collections & Research staff.

For mollusks and other invertebrates:

For birds and mammals:

About the Collections

The collections at the Delaware Museum of Nature and Science consists of over 2 million mollusk specimens and more than 113,000 bird specimens. Many have been vouchered over the years to help provide a permanent reference of organisms. After they are identified, they are cataloged and given a number for easy access and sharing through virtual databases.

Documenting and digitizing the data enables scientists from all over the world to use our collections for their research. Here are two examples of vouchered specimens:

A search for this osprey skull (Pandion haliaetus) through an online data portal by its catalog number (DMNH 82409) reveals it was collected in 1994 near Bethany Beach, DE, and vouchered to the museum.

The bird skin, skeleton, and tissue collections are fully databased and searchable online through iDigBioVertNet and GBIF.org

This ribbed mussel (Geukensia demissa) specimen (DMNH 231836) was collected in the Mispillion Harbor in Milford, DE in 2006.

The mollusk collection is digitized on iDigBio and InvertEBase.

These Brachioteuthis beanii came from the Gully Marine Protected Area off the coast of Nova Scotia, Canada. They were part of 44 lots of 245 specimens that were vouchered at the museum in 2007 and continue to be used in research.

Thousands of Mollusks added to the museum’s scientific collections in 2023

Mollusk collections often stem from exploration, whether on a global or local scale. Personal collections frequently find their way to museums, especially when accompanied by available data. Our holdings have recently expanded with two significant acquisitions.

During the past summer, Kathryn Eickhoff-Smith generously donated the Read family collection, comprising approximately 10,000 marine and land snail shells from worldwide origins. This collection embodies the collecting endeavors of sisters Ella Howard Read (1845-1914) and Clara Anne Read (1850-1928) from Massachusetts.

While they didn’t gather the snails themselves, they likely acquired or traded for these shells through connections to their family’s involvement in whaling operations in New Bedford. These shells, treasured for their beauty and novelty, were showcased in exquisite custom-made cabinets, a common practice of that era. The specimens were transported back to the museum still in the cabinet drawers by Mollusk Senior Collections Manager Alex Kittle (pictured below) who drove to Naples, Florida to pick up the collection last fall.

The Read sisters’ father was associated with the Willimantic Linen Company, and many of the smaller shells were stored in boxes produced during the latter half of the nineteenth century with the company’s logo. The image below shows the label on one of these small boxes.

The second collection originates from Laura Zeller, a longstanding shell collector based in the Baltimore area. Comprising 210 lots of tiny specimens, this collection primarily features specimens from the United States, Thailand, and other distant locations.

The next step for both collections involves matching the shells with their respective data. While the Zeller collection benefits from an index and notecards, the Read family collection presents a greater challenge, potentially requiring collaboration with other museums to piece together details such as possible collection dates. 

The du Pont Trophy

Connecting art with science: the du Pont Trophy original paintings by artist Lauren J. Sweeney

For more than 50 years, the museum has presented the du Pont Trophy Award to the “overall outstanding exhibit” entered at shell shows around the country. The award honors exceptional citizen scientists having a passion for shells, shell collecting, and the natural history of mollusks.

For the majority of its history, the du Pont Trophy was a simple engraved plaque. As part of the Museum’s 40th anniversary celebration in 2012, Director of Collections and Curator of Mollusks, Liz Shea, Ph.D. re-imagined the award to celebrate the variety in the museum’s vast collection of more than two million mollusks. She turned to long-time museum supporter and local artist, Lauren J. Sweeney, Ph.D. to make this vision a reality. The result is an original watercolor highlighting a different shell from the collection each year. A framed limited-edition, signed print of this commission is presented to the du Pont Trophy winners.

Lauren Sweeney’s paintings are informed by a lifetime of scientific observation. Originally a biologist who focused her talents on research, teaching, and scientific illustrations, Lauren is now a full-time artist. Her attention to detail brings the shape, color, texture, and pattern of her subjects into sharp focus. Lauren has exhibited her work in the greater Philadelphia area, including the Sketch Club, Gallery Twenty Two, and the Main Line Art Center.

For more information about the artist, visit www.inliquid.org.

The original paintings, currently on exhibit, are for sale for $600 to benefit the museum’s collections.

2023 duPont Trophy

Lambis lambis

The 2023 du Pont Trophy features the changing morphology of Lambis lambis. These dramatically different stages are symbolic of the major metamorphosis the museum experienced over the past few years. The Delaware Museum of Nature and Science reopened to the public in May 2022 with completely renovated exhibit spaces.

2022 duPont Trophy

Melongena corona

This painting depicts the marine snail Melongena corona as positioned on Curator of Mollusks Elizabeth Shea, Ph.D.’s kitchen table. The specimen (and setting) was chosen in recognition of the chaotic year ushered in by COVID.

SOLD

2020 du Pont Trophy

Spirula spirula

This painting features the internal shell of Spirula spirula, a deep sea cephalopod commonly referred to as ram’s horn squid. They are more often collected as shells than as live organisms. S. spirula was selected for the painting in recognition of research projects conducted by Widener University students.

2019 du Pont Trophy

Tellina radiata

This specimen of Tellina radiata, a bivalve mollusk commonly known as the Sunrise Tellin, is from the Alison Bradford collection, bequeathed to the museum by Alison Bradford, a longtime volunteer and member of the Board of Trustees. Bradford had been at the museum for over 30 years. She passed away in the summer of 2018 and transferred her collection of more than 1,000 shells to the museum, most collected in Gasparilla Island, Florida, where she owned a home. 

2018 du Pont Trophy

Haliotis fulgens Philippi

The pearlescent marine sea snail abalone is the inspiration for the 2018 du Pont Trophy, featuring two specimens of the green abalone Haliotis fulgens Philippi, 1845 (DMNH 10958). These specimens have a beautiful nacreous layer and were selected by the museum’s first Mollusk Curator, R. Tucker Abbott, for illustration in the second edition of American Seashells. Published in 1974, the book is an essential resource for shell lovers and an important part of the museum’s history.

SOLD

2017 du Pont Trophy

Liguus crenatus variation

The 2017 du Pont trophy was based on shells owned by renowned Delaware illustrator Frank Schoonover, a gift from one of his most well-known clients, Irénée du Pont, owner of Granogue in Delaware and the fabled Xanadu mansion in Cuba, where the shells were collected. The shells were donated to the museum in December 2015 by Schoonover’s grandson John Schoonover.

2016 du Pont Trophy

Anodonta imbecilis from Florida

This year’s shell is a group of freshwater bivalves, commonly known as Paper Pondshells, collected in Lake Talquin, Florida in 1954. Freshwater bivalves are the focus of a recent National Science Foundation grant that will help the museum share its collections on the web.

2015 du Pont Trophy

Leporicypraea mappa variation

The museum’s mollusk collection contains over 250,000 boxes (or “lots”) of shells, making it one of the largest collections in North America. The Map Cowries in this painting highlight the depth of the museum’s holdings and the variation found within a single species.

2014 du Pont Trophy

Spondylus with data label

New collections come into the museum from many sources, often accompanied by old data labels. This specimen of Thorny Oyster is a beautiful and ornate U.S. species, complete with an interesting original data card.

2013 du Pont Trophy

Scaphella junonia on sand

Finding a Junonia on the beaches of the Florida Gulf Coast is cause for celebration. This composition highlights the popular marine snail resting on a background of sand collected from Boca Grande, Florida by long-time museum trustee and volunteer Alison Bradford.

SOLD

2012 du Pont Trophy

Festilyria duponti holotype

The subject of the first watercolor is Festilyria duponti, a shell named by Clifton Stokes Weaver in honor of Delaware Museum of Natural History founder, John E. du Pont. The background is a representation of a technical book on shells, co-authored by du Pont and Weaver.

New species discovered using museum’s online collection data

Introducing Bourciera ovata

In the summer of 2020 — the first year of the pandemic — a team of European scientists began compiling a checklist of known terrestrial and fresh water mollusks of mainland Ecuador. The effort included occurrences recorded in past scientific reports or literature, museum datasets available online, and verified observations from citizen science projects like iNaturalist.

In reviewing our records, one of the scientists, Marijn Roosen of the Natural History Museum of Rotterdam, noticed some unusual records of a unique land snail in the Andes Mountains. Marijn requested more information about the snails and photographs to confirm their identifications. It turned out that some of the specimens from Puyo, Ecuador represented species previously unknown to researchers, including the newly-named Bourciera ovata.

With high resolution photographs of different aspects of the snail’s shell, Marijn was able to describe it as a new species, demonstrating a greater diversity of Ecuadorian land snails and the importance of having museum collection data accessible, as surely there are many more new species to be discovered. The research was published in September in the journal Folia Malacologica.

DMNH 151926, formerly thought to be Bourciera fraseri, is now the type specimen for the newly-discovered species Bourciera ovata. A type specimen is the specific specimen on which a new species is based. The museum’s mollusk collection already included around 1,200 type specimens. Photos by Alex Kittle.

Roosen, M. and Dorado, C. Revision of the genus Bourciera Pfeiffer, 1852 (Gastropoda: Helicinidae), with the description of six new species from Ecuador and Peru. Folia Malacologica, 30(3), 155–167. https://doi.org/10.12657/folmal.030.018

Taxonomy changes reflected in new specimen organization

The introduction of Bourciera ovata is just one example of how what scientists know about species and their taxonomy continues to develop. While working from home during the pandemic in 2020, Collections Manager Alex Kittle began reorganizing the mollusk collection based on updated information and species names, and later moved the actual specimens to reflect these changes. Information about our entire mollusk collection is now publicly available on the Symbiota portal, InvertEBase. Our collection profile shows 233,603 records are available online, representing 500 families and 15,658 species; 32% are georeferenced to specific locations.

Collection Manager of Mollusks Alex Kittle in the DelMNS scientific collections.

Mobilizing Millions of Marine Mollusks

The museum has teamed up with scientists at several major museums and universities for a $2.3 million, four-year grant from the National Science Foundation to digitize data for more than 4.5 million marine mollusk specimens such as mussels, oysters, clams, and snails collected along the Eastern seaboard from the U.S.-Canada border to U.S.-Mexico border.

The project, Mobilizing Millions of Marine Mollusks of the Eastern Seaboard, will have a world-wide impact on biodiversity documentation and study by making data from these ecologically and commercially important species available through online portals. Previous digitization projects have focused on freshwater and land mollusks; this is the first major project of this type for marine mollusks.

The Field Museum of Natural History is the lead (principal investigator) for the project. Other collaborating institutions include the Academy of Natural Sciences of Drexel University, Carnegie Museum of Natural History, Harvard University, University of Florida, University of Michigan Ann Arbor, Los Angeles County Museum of Natural History, and North Carolina State Museum.

iDigBio provides a great platform for the project summary, other collaborators, and more information here.


This material is based upon work supported by the National Science Foundation under Grant Nos. 2001510, 2001290, 2001507, 2001515, 2001523, 2001528, 2001536, 2001546, 2001570, 2001600. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.