Summer is a busy time in the Invertebrate Zoology (IZ) department, as members of IZ come and go to destinations throughout the United States, and sometimes beyond. That said, IZ also accommodates an influx of visitors to its collections. In a previous No Bones post, we gave an overview of visitors to IZ. In this post, we highlight the story of one long-term team of visitors with a very special story to tell about Alabama crayfishes.
What's so interesting about crayfish?
Crayfish, also known as crawfish, crawdads, and mudbugs, can be found throughout the world. In particular, North America is home to nearly 400 species. "We have more in North America than anywhere else in the world," says Guenter Schuster, crayfish expert and co-author of The Crayfishes of Kentucky. "Their diversity is very important. In terms of ecology, crayfishes tend to be the largest invertebrates in aquatic systems, and ultimately can be found in very high numbers. They're an intricate part of the ecosystems in which they live."
That said, thorough documentation of existing crayfish species is lacking, which limits the work that biologists can do based on crayfish. For example, crayfish species could be important indicators of water quality or ecosystem health, but without a more clear understanding of the number of species, their geographical distributions, and how those distributions are changing over time, scientists are limited.
This is where Guenter and his colleagues, Christopher Taylor and Stuart McGregor, are committed to helping the field. Their focus is producing an extensive documentation of the crayfish species of Alabama, which typically relies on morphological descriptions (and lots of photographs!), in a book.
Publishing a book on the crayfish of Alabama
Guenter and Christopher's previous work, The Crayfishes of Kentucky, took approximately 10 years to bring to completion. After its release, the pair was contacted by interested parties in the state of Alabama, who asked whether it would be possible to produce a similar edition for their state.
"The main reason we were interested in Alabama is that this state has the largest number of crayfish species in the country. It's just a really, really great place to be working on crayfishes. In 2005, when we were contacted, Alabama really hadn't put much energy or time into determining the species in the state and how they were distributed. The folks in Alabama decided it was a big hole in their knowledge of the natural history of the state," says Guenter. "Chris and I talked over the project and decided that we really wanted to do it."
First in this process, the team applied for grants to visit museums. Museum collections, such as the crayfish collection here in the National Museum of Natural History, the Tulane Museum of Natural History, and the Ohio State University's collection, were an integral starting point, offering hundreds of crayfish collections for study, including information on the collection date and location of each specimen.
"We also did a literature survey to see what publications had come out on species in Alabama. Once we got a rough list of the species in Alabama, the next step was to figure out where most of the work had been done in the state and where additional work needed to be done," relates Guenter.
Using the locality information from the collections and publications, Guenter and his team built a geospatial map of the crayfish species in Alabama. Using this map, the team identified locations for further collecting. "It's been very rewarding, to be able to collect in places no one has collected before. The other part is to go back to where species were collected previously and see what's still there. Things that showed up 150 years ago may not necessarily still be there anymore. So we had to go back into the field to see if those species are still living in those original locations and how they're doing," describes Guenter. He estimates that the team has carried out collection field work in Alabama four to five times per year, for the past nine years in a row.
Finally, after all of the "hard" work, Guenter is pursuing the portion of the project that he seems to like best - photography. On his recent visit to IZ, Guenter photographed dozens of crayfishes. Preserved specimens lose their color over time, fading to a ghostly white. Guenter notes that "it's usually not that big of a deal, because color has not been used extensively in identification of crayfishes, whereas structures - hard structures - have been."
He continues, "but now that we've taken photographs of most of the crayfishes in Alabama, we've come to realize that most species have rather unique colors. One thing we're going to point out in the book is that maybe we can start using color patterns in live crayfishes to help in the identification process."
Key role of Smithsonian's collections
Guenter specifically identifies the work of Horton Hobbs, curator of crayfishes in IZ for more than 50 years, as integral to their project, noting that Horton's work amounted to "the greatest crayfish collection in the world. The value of the collection at the Smithsonian is just immense; certainly there are crayfishes from all over the world, but there are also hundreds of lots from Alabama in that collection."
Guenter estimates that he and Chris have looked at thousands of specimens at the Smithsonian. For example, their work requires comparisons of the species from Alabama to species from adjacent states, such as Mississippi. Over the course of this work, Guenter has gathered hundreds of photographs of IZ specimens, many of which will be incorporated into the team's book.
Summing up the visitor experience, from visitors who definitely know
Guenter simply couldn't say enough positive things about his experience as a visitor to IZ, where he has developed a close working relationship with several of the collections management staff. "They have been absolutely great. Every time we've gone - multiple times - they bend over backwards to help us out. If we have questions about the specimens, they help us tremendously to find what we need. They provide the space, microscopes. It's really been a very, very positive relationship to work with them."
In particular, museum specialist Karen Reed, who has a specific interest in crayfish, has enjoyed offering support to Guenter and his colleagues when they visit. According to Guenter, Karen's enthusiasm, hasn't gone unnoticed: "Karen Reed knows the collection very well. She's always available to answer questions. Very early on, we asked Karen to query the database for what the Smithsonian had in terms of Alabama crayfishes. When she did that, we immediately found that there were over 2,500 crayfish records just for Alabama. That was really a huge beginning for us and the book project."
Finally, Guenter notes that even before compiling their book, the team has identified one crayfish species, the Slenderclaw crayfish, that is in need of protection. "First described in the 1970s, the Slenderclaw hadn't really been collected again until the 2000s, when we started our work. We tried to collect it on three different occasions at all of the original locations but weren't able to find any specimens from them. That tells us there's been a huge decline in the population. In recent years we've only gotten a handful of specimens in a previously unknown location," says Guenter. “We are working with the U.S. Fish and Wildlife Service to try to get it listed on the Federal Endangered Species List.”
"It seems like this particular species is really in trouble right now, the exact reason for this is unknown. But we're hoping that if we get some other biologists interested, we can figure out exactly what's going on with it," Guenter explains. Publishing the most complete book on Alabama crayfishes is certainly a good way to start!
by Liz Boatman
Great article on Guenter Schuster and Chris Taylor's work!
Posted by: Helga Miller | 18 July 2014 at 01:46 PM