by Rachel Ewing
In most year-in-review posts, we take the opportunity to reflect on experiences and stories, both local and global, that we took note of over the past 12 months. But this one is about new finds that you might not have heard about—and it’s remarkable how unremarked such things can be. Every month of every year, scientists continue to add pages to the catalog of life on Earth, discovering and documenting new species from the swimming to the squirmy to the photosynthetic and microscopically beautiful.
At Drexel and the Academy of Natural Sciences of Drexel University, scientists have helped enter dozens of new species into the scientific record during 2014. Below, take a look at some of these new discoveries.
Two Crane Flies Flit into the Books
Sometimes known as “Daddy long-legs flies” for their long legs, crane flies are an extremely diverse group of insects. About 15,000 species are known, and scientists estimate there may be about 10,000 more species not yet described.
This year, two of these species have shifted from the “unknown” to the “known” column thanks to the efforts of crane fly expert Jon Gelhaus, PhD, curator of entomology at the Academy of Natural Sciences of Drexel University and a professor in Drexel’s College of Arts and Sciences, and his collaborators.
With co-authors Sigitas Podenas, and Virginija Podeniene, Gelhaus described the crane fly Heterangaeus mongolicus from north central Mongolia. The discovery was one of many as part of the NSF-funded Mongolian Aquatic Insect Survey project that Gelhaus leads. The project helps not only to identify new species, but also to train Mongolian scientists and to develop key measures to monitor environmental health in that country.
Also in 2014, with Jorge Mederos-López, Gelhaus discovered the crane fly Trentepohlia inexpectata from Cuba.
“Both species of crane flies, although described in different parts of the world, share the common feature that they were totally unexpected where they were found (in fact the species epithet for the Cuban species is ‘inexpectata’!),” Gelhaus said. “These new species are living a one or two thousand kilometers from their nearest known relative (for the Mongolian species, its nearest relatives are in Japan and the Russian Far East; for the Cuban species, its nearest relative is in Costa Rica). The Mongolian Heterangaeus was additionally a special find as we were able to learn something about its biology and natural habitats, and we described the immature stages (larva, pupa) for the first time for any members of that group.”
Thorny-Catfish Dream Team Nets a New Amazon Basin Find
Nemadoras cristinae entered the scientific record in April, the result of a collaborative effort by the world’s four top authorities in thorny catfishes, or doradids: Mark Sabaj Pérez, PhD, collection manager of ichthyology at the Academy of Natural Sciences of Drexel University, Mariangeles Arce H., PhD, a postdoc at the Academy, and Brazilian scientists Leandro M. Sousa and José L. O. Birindelli.
“Over the past 10 years, at least one of us has been involved in the descriptions of 21 species of doradids (there are 95 species total),” Sabaj Pérez commented. “Of course…there are only four doradid authorities in the world…”
Sabaj Pérez and other Academy ichthyologists have worked extensively on studies of fish of the Amazon basin, including a major NSF-funded project to document the biodiversity of fishes in the Xingu River before and after the installation of the Belo Monte dam.
The new catfish, from the upper Amazon and Madeira basins, was named for Maria Cristina Sabaj Pérez, the scientist’s spouse and a teacher at Friends’ Central School in Wynnewood, Pennsylvania The scientific paper describing Nemadoras cristinae notes that the new life form bears her name in honor of “her contributions to the collection of the type series and to the well-being of the senior co-author, videlicet course corrections over paths polished and rough.”
Thirteen Microscopic Water Sentinels Emerge
Eunotia ninae, one of five diatom species Potapova described in 2014 from an island in the Northern Pacific. The others are E. prilezhaevii, Diadesmis mochalovae, Psammothidium strelnikovae and Pinnularia beringensis.
Brachysira subtile, one of four diatom species from a lake in eastern Siberia described by Potapova with collaborators P.B. Hamilton and L.I. Kopyrina. The others are Eunotia frigida Potapova, Hamilton & Kopyrina, Encyonopsis vasilievae Potapova, Hamilton & Kopyrina and Neidium rugosum Hamilton, Potapova & Kopyrina.
Cavinula maculata, a diatom species from North America described by Potapova with collaborators A. Cvetkoska, P.B. Hamilton & Z. Levkov. This team also identified Cavinula kernii Cvetkoska, Hamilton, Levkov & Potapova as part of the same study of the distribution of this genus of diatoms.
Some of the most fascinating forms of life are invisible to the naked eye.
Marina Potapova, PhD, assistant curator of diatoms at the Academy of Natural Sciences of Drexel University and an assistant professor in Drexel’s College of Arts and Sciences, is one of the world’s top authorities on diatoms, tiny one-celled plants that live in waterways worldwide and are powerful indicators of water quality.
The types of diatoms present can tell scientists a lot about the conditions of the environment. (This key insight was a major contribution to science by the late Ruth Patrick, a longtime Academy scientist for whom the museum’s diatom collection is now named.)
In 2014, Potapova was involved in the naming of 13 new species of diatoms.
“Of all species published this year, the most interesting is probably Encyonema appalachianum,” Potapova commented. “While most other new species are from relatively poorly studied and remote geographic areas (a lake in eastern Siberia and an island in Northern Pacific), E. appalachianum was found in Pennsylvania, which is a relatively well-studied place. I first found E. appalachianum in Youghiogheny River in May 2013 while surveying rivers of Western Pa. This work was supported by a grant from the Pennsylvania Department of Conservation and Natural Resources. Later that summer I found populations of this species in eleven other rivers and lakes across Western Pa. and then it was noticed in the Susquehanna River. This is a rather distinctive species and it’s difficult to image that it was overlooked in the past. Perhaps it is a species that had a limited distribution in the past and is now expanding its range. What causes such changes in geographical ranges of microbes? Is this an indication of some human impact or climate change? These and other questions in the microbial biogeography and ecology are practically unexplored and await further research.”
For more images of diatoms and Potapova’s work, see a slideshow from the 2014 edition of Drexel’s EXEL magazine.
Colorado Yields a Delicate Stonewort
Tolypella ramosissima. Credit: William Perez
Diatoms aren’t the only new algae on the scientific scene.
Rick McCourt, PhD, associate curator of botany at the Academy of Natural Sciences of Drexel University and a professor in Drexel’s College of Arts and Sciences, was part of the team that named a new species of stonewort (a type of algae) from Colorado. The first author of the paper, William Perez of New York City, was a doctoral student at the City University of New York at the time of the discovery and has since earned his PhD.
The team named the stonewort Tolypella ramosissima, which means “little forceful one with many branches.”
“It’s a delicate little plant a few inches high that grows in quiet, freshwater habitats,” McCourt said. “Its branches have tips that look like little birds’ nest clusters of green threads.”
Seven Secretive Snails Get Scanned
Little-known fact: Snails can be inscrutable. That is, some snail species are known to science primarily through the characteristics of their shells, found after the living animal inside the shell has died and decayed. This is the case with most snails in the genus Thala, of which Academy scientists described seven new species this year.
“Virtually nothing is known about the biology of Thala,” said Gary Rosenberg, PhD, Pilsbry chair of malacology at the Academy of Natural Sciences of Drexel University and a professor in Drexel’s College of Arts and Sciences. “Most species have never been observed alive, but they are nonetheless fascinating for their beautiful color and sculpture, the function of which is currently unknown.”
Rosenberg, along with Richard Salisbury, described the seven new species based on observing the shells under a dissecting microscope before using scanning electron microscopy (SEM). The SEM showed them that the tiny microstructures of the shells can be unique to different species.
Rosenberg notes that Thala are a great example to understand how scientists’ perceptions of the diversity of species change over time; it isn’t always a beginning-to-end process of finding something, declaring it new, and adding it to the list of known species in a specific category. Sometimes those lists get rethought and reorganized. For example, perceptions of Thala species have both shrunk and grown. “George Washington Tryon, one of my predecessors as curator of mollusks here, recognized a dozen species in the genus in 1882,” Rosenberg said. “In 1970, Walter Cernohorsky, a scientist in New Zealand, synonymized some of those and recognized only six species. We now recognize 49 species in three genera in this group, with at least half a dozen more that have yet to be named, so there has been almost a tenfold increase in perception of diversity over the last 40 years.”
This story first appeared Dec. 22 on the Drexel News Blog.