debor042

post by David Williams* Although he never wrote it down, the late Colin Patterson , one time vertebrate palaeontologist at my home from home, the Natural History Museum , London, often said that when confronted with any particular biological specimen, three questions should come into the minds of systematists: What is it? What is it related to? Where does it live? For me, the first is often a struggle, as wading through books of images can be a tad soul-destroying, especially if the images never quite match what’s in front of you. Start with something easy – that’s what Frank Round told me, a long while ago now. Easy? There’s a lovely book by Archie Carr, A Naturalist in Florida, A Celebration of Eden (1994). In it there’s a key to the fishes of Alachua County, Florida, first published in 1941. One instruction reads: “Not as above; fins with dangerous spines; catfish-like—in fact, a catfish”, with a footnote: “Any damned fool knows a catfish”. So, Frank suggested Fragilaria virescens...

In the last year and a half, ten different authors have talked about 19 diatom species from 19 different genera in our “Diatom of the Month” blog series (11 biraphid, 2 araphid, 2 centric, 1 epithemioid, 1 eunotioid, 1 monoraphid, and 1 nitzschioid), and we got to know about some fantastic 2D and 3D diatom art . We reached thousands of people online via social media (see image below), thus raising awareness about these beautiful and extremely useful primary producers and environmental indicators. We importantly relied on the wonderful “ Diatoms of the United States ” resource for reference and inspiration, which has so far produced taxon pages for 155 genera (25  are u nderway ), and 851  species (202  are u nderway ) ! This was made possible over the years by more than 110 taxon contributors , an effort led by Marina Potapova, Sarah Spaulding, and Mark Edlund and kept under scrutiny by the review board members . The DOTUS Facebook page provides regular updates and fea...

by Nick Schulte* I think Fragilaria synegrotesca is a cute diatom. Although long and lanky (nothing wrong with that!), F. synegrotesca has an adorable, sometimes very slight, potbelly (Fig. 1).                    Fig. 1 . a)  Live frustules in a rosette colony ( http://fcelter.fiu.edu/data/database/diatom/index.htm?species=3568 )   b) Fragilaria synegrotesca  in valve view (Schulte 2014). Now, some boring diatomist (e.g., me ) might describe that little bump in the middle right as “a unilaterally expanded, hyaline central margin” and that’s accurate enough. But I also like to think of it as F. synegrotesca ’s belly pooch. It brings to my mind the potbellies of seahorses, pigs, puppies and toddlers, and it seems very boop-able. But let’s move past the physical attributes of this diatom, as the allure of this species is in its “actions”. Fragilaria synegrotesca has so far only been reported from karstic wetlands of t...

by Martyn Kelly*, in collaboration with Luca Marazzi Navicula lanceolata (Agardh) Ehrenberg 1838 is a symmetrical biraphid diatom with lanceolate valve margins, broad in the central valve and slightly rostrate, rounded ends (Fig. 1, #1); the central area is an irregular oval (Fig. 1, #2), and striae are radiate, except at the ends where they become convergent (Fig. 1, #3). This species has two chloroplasts, one along each side of the girdle (Fig. 2) and is highly motile. Fig. 1 . Navicula lanceolata (Source: http://westerndiatoms.colorado.edu/taxa/species/Navicula_lanceolata ) . Fig. 2 . Navicula lanceolata in fresh samples with brown chloroplasts (Source: http://craticula.ncl.ac.uk/EADiatomKey/html/taxon13521390.html ; Image Copyright: E.J. Cox ). This is one of the most widely-distributed and frequently-encountered diatoms in both Europe and North America and is particularly abundant in winter and early spring; like a few other motile diatoms, it can form dark-brown patches on...

by Sylvia Lee, FIU & Periphyton lab alumna Did you know that March 19 is Taxonomist Appreciation Day ? Fig. 1 . Cartoon on what taxonomy is. Image credit: BuzzHootRoor from https://smallpondscience.com/2014/03/19/today-is-taxonomist-appreciation-day/ Taxonomy is the study of organisms and their classification (or in more witty/punny terms in the image above, “how you phylum ”). Recognizing and putting names to organisms may come easy to some natural-born naturalists, but taxonomy can be a challenging task requiring specialized knowledge. This is especially true for groups with many species, such as diatoms. Species identification may not seem like an important skill, but it can be thought of as an essential part of “ ecoliteracy .” It is difficult to care about something if you do not know its name , and it can even become extinct without your knowledge. As part of my Ph.D. research, I was able to do an in depth study of some of the diatoms in the Ev...

The Art of Diatoms by Xavier Cortada Artist-in-Residence FIU School of Environment, Art and Society   Fig. 1. Cortada’s one-hundred diatom works on tile (each 6″ x 6″), 2017. I marvel at looking into a microscope.  I focus in and see time. I see the past, really far into the past. I see beautiful small aquatic plants encased in glass that lived on our planet for many millions of years. Sitting inside Dr. Evelyn Gaiser’s Algae Research lab at Florida International University in Miami, I look at a slide   and see diatoms.  Diatoms transport me to a place so distant in time that it wouldn’t look like the Earth I know. They help connect me to an Earth I am trying to better understand. An Earth fluid. An Earth as process. An Earth completely interconnected. An Earth generating life forms across space and time.  Fig. 2 . Xavier Cortada, Drawings of Diatoms from the Everglades, 6″ x 6″, ceramic tile, 2017. In diatoms I also see moments captured in time.  Scienti...