I spent today attending the annual meeting of the Virginia Academy of Science, held this year at the University of Richmond. Specifically, I was attending the Natural History and Biodiversity section, which included 15 talks and 4 posters. While I wasn’t presenting at the meeting, I went to support two of my student collaborators from Roanoke College, Laura Kellam (who is working on Balaenula) and Brandi Neifert (who is working on Carmel Church sharks). Since I’ve discussed their research in earlier posts I won’t repeat it here, but while these were the only two talks on paleontology, there were numerous other fascinating topics being presented.
One of my fellow curators at VMNH, Curator of Mammals Nancy Moncrief, co-authored a talk with W. D. Webster, J. R. Choate, and H. H. Genoways on the northern short-tailed shrew Blarina brevicauda (skeleton below on exhibit at the US National Museum):
Specifically, they examined skull size and shape and genetic similarities among thousands of specimens, identifying 7 different subspecies, with both the morphologic and genetic data in close agreement. Remarkably, 2 subspecies cover almost the entire range of the species and are separated from each other by the Mississippi River, while almost all the others are very small but distinct populations either on the periphery of the main range, or in rather geographically isolated environments. These seem to represent textbook examples of incipient parapatric speciation. This research is detailed in the recently published VMNH Memoir No. 10, available as a free pdf download.
S. A. Caplins, J. M. Turbeville, and J. L. Norenburg presented on a group with which I was almost completely unfamiliar, proboscis worms from the phylum Nemertea. The specific taxon they are studying, Nemertopsis bivittata, is a barnacle predator. Their presentation included a rather horrifying video of a Nemertopsis feeding, which involves stabbing the barnacle with a mineralized spike and injecting a neurotoxin that effectively paralyzes the barnacle. Then the worm fully inserts its proboscis, pours digestive juices into the shell, and finally sucks up the dissolved barnacle. There actual research is an attempt to demonstrate that N. bivittata may actually be two distinct species, based on morphological and genetic differences.
J. P. Bredlau and K. M. Kester examined features that may serve to reproductively isolate populations of the parasitic waspCotesia congregata. These wasps have a fantastically complex reproductive strategy, which involves using olfactory cues from plants to locate host caterpillars, and upon laying their eggs on the host, injecting a virus that inhibits the host’s immune response. With so many reproductive stages, there are lots of places where populations can become isolated.
L. Wilson, C. W. Edwards, and P. M. Gillevet discussed preliminary data on the effects of global climate change on the distributions of swans. While many species are being adversely affected by climate change, one beneficiary is the Alaskan population of the trumpeter swan Cygnus buccinator (top of page, from the Minnesota Zoo). C. buccinator prefers wetlands associated with spruce forests, which are rapidly spreading north and supplanting tundra as the Alaskan climate warms. Of course, the loser in this scenario is the tundra swan Cygnus columbianus, which, as the name implies, prefers tundra habitats.
J. D. Kreitzer looked at the relationship in feathers between melanin content and durability. There is a published body of research that indicated that feathers that are high in melanin are harder and more resistant to abrasion. Kreitzer is looking at the possibility that melanin is preferentially located on the primary flight feathers, which experience the greatest amount of stress, as seen in this gull:
There were two talks involving mosquito larvae. The first, by A. Frisa and D. A. Waller, presented preliminary results on the effect of sunlight duration on larval development. It seems that the larvae require at least some sunlight, and there are hints (not statistically significant with the small sample) that the amount of light may affect the sex of the larvae. The second talk, by J. McKee and D. A. Waller, examined how mosquito larvae respond to the presence of a predator. In the absence of predators, early stage larvae prefer light backgrounds while pupae prefer dark ones. Throwing a predator into the mix doesn’t seem to change the behavior of the larvae at all.
T. A. Egerton, M. R. Semcheski, and H. G. Marshall looked at massive amounts of data on plankton from the Chesapeake Bay. How massive? Over 1000 phytoplankton taxa and 430 zooplankton taxa! They found that as nitrogen and phosphorus in the Bay increases (from fertilizer-rich runoff), the abundance of phytoplankton increases, but the diversity drops (in other words, numbers of individuals increase, but from fewer species). Zooplankton show a different pattern, however; both abundance and diversity decrease. Fisheries data indicate that capture yield (total weight of fisheries catches) also decreases when N and P are high.
B. L. Barron, J. E. Bisset, L. E. Lewis, D. A. Milhon, C. M. Miller, B. S. Sawyer, A. L. Smith, J. V. Stevens, and W. S. Bousquet looked at the changes in ecological communities in small preserved wetlands in and around Winchester from 1998 to 2010. For some of the sites, the changes were staggering, with almost a total change in community structure. It seems that some of these preserves are too small to sustain themselves against invasive species, at least without some active management.
K. J. Bolyard discussed the mating behavior of the Potomac sculpin, Cottus girardi. Apparently it’s a rather impressive process for the males, involving a color change, waving pectoral fins, body shaking, biting the female on the head (!), and running off other males. In the small sample presented, females almost always chose the larger of the available males (maybe size does matter to sculpins).
Z. N. Ghahramani, Y. J. Mohajer, and M. L. Fine used high-speed video to examine sound production in the blue catfish, Ictalurus furcatus (example below from the Texas Memorial Museum). I. furcatus produces sounds by dragging spines on the pectoral fin against the pectoral girdle. Video shows that the fish moves the spine back smoothly and rapidly, but moves it forward in pulses, rubbing bony ridges against the girdle and causing the girdle to vibrate.
J. F. Charbonnier, T. Landberg, and J. R. Vonesh discussed how external factors can affect tadpole development. In some taxa, keeping developing tadpoles in a covered environment can result in larger frogs, but for a given body size the tadpoles from an open environment have greater speed and endurance (the talk included video of the frogs on a miniature treadmill). Likewise, in other taxa the number of tadpoles in the environment can apparently affect size and jumping ability.
J. M. Kanine, M. T. Mengak, and S. B. Castleberry looked at presence/absence data of woodrats (Neotoma magister) at localities in Virginia. Part of their study examined the relative effectiveness of traps as compared to cameras; cameras tend to allow better coverage over an area, but traps allow confirmation of recaptures and collection of tissue samples. One interesting result is a plummet in woodrat numbers from 2009 to 2010, apparently as a result of few acorns and heavy snow in the preceding winter.
I also want to note the two high school students from the Virginia Junior Academy of Science that were invited to speak in our section. Hannah Heimer examined whether or not sleep deprivation affects the memory of fruit flies (apparently it doesn’t), while Natasha Sheybani looked at the development of communication between the thalamus and the visual cortex in mice.
This was a fun session for me, as it’s very educational to occasionally step outside your comfort zone and see what researchers in disparate fields are working on. I also plan to attend next year’s meeting in Norfolk.