For part of my spring break I had the pleasure of visiting an old friend and colleague of mine, Dr. Nicole Pietrasiak (@drylandalgae) at New Mexico State University. What a blast!
We talked about ongoing and future collaborative projects, all of which revolve around soil algae, especially those living in cryptogamic crust communities. Dr. Pietrasiak is an expert on soil crust ecology and biodiversity, with a focus on cyanobacteria. So what is a soil crust?
This lumpy stuff on the ground 🙂 – while they may not look like much, soil crusts are a vital component of desert ecosystems. Numerous and diverse micro- and macroorganisms including fungi, bacteria, algae, protozoans, lichens, mosses and invertebrates form communities that aggregate the soil particles into, well, crusts. Without crust cover, desert soils can be extremely prone to erosion, resulting in a multitude of problems including dust storms and loss of soil. Crusts are also thought to help the establishment of native plant communities, which are essential for the ecosystem’s health and biodiversity.
Many new species of microorganisms have been discovered by studying soil crusts – this is largely thanks to the advent of DNA sequencing, which helps distinguish similar-looking but genetically and evolutionarily distinct organisms. Nevertheless, many more are undoubtedly still waiting to be discovered, as deserts emerge as the new yet rather unsuspected biodiversity hotspot. Like the Amazon rainforest, but dry! I am excited to be a tiny part of this quest for discovery.
Another coauthored paper (with lead author A. Saber, H. McManus, G. Guella and M. Cantonati) describing a new genus of desert algae, Pharao desertorum, was just accepted into Journal of Phycology. We also present data on three other desert isolates, and for two of them we show lipid and pigment profiles, as these putatively reflect adaptations to the desert extremophilic lifestyle of these algae. Coming soon in JPhycol Online Early!
A collaborative paper just got accepted in American Journal of Botany: McManus HA, Fučíková K, Lewis PO, Lewis LA, Karol KG. Organellar phylogenomics inform systematics in the green algal family Hydrodictyaceae (Chlorophyceae) and provide clues to the complex evolutionary history of plastid genomes in the green algal Tree of Life. Coming soon in AJB open access! (image: member of Hydrodictyaceae, Pediastrum duplex – photo by Emily Norman)
Our student researchers presented the results of their summer’s work in a poster session on Friday afternoon in the Testa atrium. We had a great turnout, and the scientific breadth covered by the various posters was really impressive – reminder how enriching it is to be in a department that includes biology, chemistry, and physics.
Super proud of Melissa, Emily (who had to run to practice before the photo was taken; I will have to photoshop her in…), Aleeza and Madison. Nice job, ladies, keep up the good work!
Our paper, Molecular and morphological delimitation and generic classification of the family Oocystaceae (Trebouxiophyceae, Chlorophyta), is now accepted in Journal of Phycology (http://onlinelibrary.wiley.com/doi/10.1111/jpy.12581/full). The article sorts the diversity of Oocystaceae into subfamilies and clades based on molecular and morphological data. Many thanks to my fabulous coauthors, especially to the lead author Lenka Štenclová, who will be coming to work with me for a couple of months at Assumption College starting next week!
The weather has been mostly spring-like these past couple of weeks and algae are definitely out and about in local water bodies. I have sampled a few wetlands including boggy pools and larger ponds and lakes in NH and MA – and the pickings are good! As is typical for the spring, the samples are dominated by chrysophytes, synurophytes, dinoflagellates and diatoms.
Colonial chrysophyte of the genus Uroglena
Colonial chrysophyte Chrysostephanosphaera
Green alga of the genus Tetraspora – note the pseudocilia (nonfunctional flagella) coming off of the side of the colony
Uroglenopsis americana, a colonial chrysophyte. Upon careful look, you can see the gelatinous stalks holding the colony together.
Mallomonas caudata, a scaled, bristled synurophyte.
A dinoflagellate, likely of the genus Gymnodinium.
Some kind of a parasite (left) sucking the life out of a diatom (right).
Some of the peat bogs also harbored desmids, my favorite kind of algae, and several species of euglenoids, both photosynthetic and non-photosynthetic (the latter are species or genera that have secondarily lost their photosynthetic superpowers).
Micrasterias truncata, a pretty desmid
Cylindrocystis brebissonii, a relative of desmids from the family Mesotaeniaceae
Anisonema, a non-photosynthetic euglenoid; image taken under phase contrast
Undoubtedly the best find was the colonial chrysophyte Cyclonexis annularis. This genus and species is considered rare and to my knowledge has not yet been reported from NH. It has, however, been spotted in the 1940’s in Andover MA, not too far from here. This little critter was swimming fast, so I could not snap a good close-up picture; I only managed to shoot a quick video of it swimming. The colony is bracelet-shaped with individual flagellated cells attached to one another by their sides. Previous authors report the colonies being very fragile and easily falling apart by physical disturbance (bumping into something) and by application of fixatives such as alcohol. Thus, I’ll probably have a hard time getting a better picture!
PS: I’ve logged all my observations into my iNaturalist project: http://www.inaturalist.org/projects/freshwater-algae-of-new-england-and-new-york