billy dalto

benjaminhilts:

Coral colonies of Montastrea annularis from a fringing reef approximately 75m offshore Playa Kalki, Curacao

This lab photo of coral and zooxanthellae was taken as part of a study on coral bleaching, a disastrous phenomenon that occurs in coral reefs, believed to be caused by global warming.

Institute for Genomic Biology | University of Illinois

Corals secrete a mucous layer to defend against pathogens and provide an environment for beneficial microorganisms. In this image, zooxanthellae appear green and mucocytes (mucous producing cells) red. More details on this study are available here.

Who’s excited about zooxanthellae? I am. That’s who.

Zooxanthellae (genus Symbiodinium) are the first intracellular endosymbionts I’ve mentioned all week. These dinoflagellates are autotrophic and not found in a free-living form. They’re important because they live in a wide range of organisms including some radiolarians, foraminiferans, giant clams, and reef-building (hermatypic) corals.

Coral growth at a rate sufficient to establish a large reef requires a lot of energy. Some hermatypic corals solve this problem by exchanging protection, carbon dioxide, and other nutrients for several products of photosynthesis provided by zooxanthellae. As a result, the health of these corals is closely tied to the health of their zooxanthellae friends.

Image from here.

This specimen is an exceedingly rare multicellular terrestrial dinoflagellate. Classification of this organism has been controversial since its discovery. However, recent analysis of its genome, bioluminescence pathways, and blue jean selection has made most phycologists comfortable placing it in class Dinophyceae.

Genus Ceratium is a thecate dinoflagellate group with very recognizable morphology; its members have one or more elongated horns, which vary in shape and size between species.

In my experience, they are the most incorrigible dinoflagellates. I ejected the one shown above from my last garden party after his advances made a centric diatom very uncomfortable. When asked to leave, he became argumentative and made grossly exaggerated comments about my mother’s size and her daily mayonnaise intake (I would rather not repeat these insults).

SEM from here.

nudawn:

YOU GUYS, ITS DINOFLAGALLETE WEEK.

Appropriately enough, i present to you Karenia brevis, a marine dinoflagellate common in Gulf of Mexico waters, and is the organism responsible for the Florida red tide.  K. brevis is a microscopic, single-celled, photosynthetic organism that can “bloom” frequently along Florida coastal waters.  K. brevis naturally produces a suite of potent neurotoxins collectively called brevetoxins, which are responsible for large die-offs of marine organisms and seabirds.

via wikipedia

Another non-thecate species has arrived. Wikipedia mentions this alga was formerly known as Gymnodinium breve. Gymnodinium is derived from the Greek words gymnos (“naked”) and dineo (“to whirl”).

Dinoflagellates are awful house guests. I cannot stress that enough. Nonetheless, it’s time to begin dinoflagellate week. The above image is of Noctiluca scintillans, a heterotrophic and bioluminescent algal species. Because it lacks cellulose armor, it is scandalously referred to as a naked (or non-thecate) dinoflagellate.

Image from here.

mills:

Today is Will’s birthday! Will is the most admirable man I’ve ever met, a friend who is quite unbelievable in his equanimity, decency, intelligence, and humor. It’s been a gift to know him.

For those interested, here are more photos of Will being awesome all over the world. If you’re trying to think of gift ideas, he likes beads, mustaches, Elton John, history, and diatoms (whatever the hell those are).

I feel very fortunate to be able to share today, or any other day for that matter, with such great friends. Dinoflagellates: just to be clear, this doesn’t apply to you. I dream of the day I’ll be able to make it through one workout without being reminded of your nickname for Las Vegas.

This is a dinoflagellate armored with cellulosic thecal plates, which have the somewhat unusual property of lying beneath the cell membrane. The dinoflagellates are a large and diverse algal group with no shortage of interesting characteristics. For example, most do not have histones and keep their chromosomes condensed for almost the entire cell cycle. I do not invite them to parties because I have little patience for guests who shout “Spartan!” every time someone goes for the guacamole.

Photo from here.

This is an example of Mitrocalpis araneafera. Tonight is already remarkable for me in at least one respect: I just caught myself wondering, as “Pinball Wizard” played in my head, whom I need to sleep with to score more high resolution electron micrographs of radiolarians.

Image from Radiolaria.org.

kateoplis:

Mills Baker

This is a lovely photo. It’s also quite telling because this is the night Mills made an important decision.