Biology

Coming soon: a totally kickass taxonomic navigation system! Seriously, when someone asks me, “So, what’s your favorite echinoderm?” or “Hey, where can I find a gallery of really shiny beetles?” — I’ll be so ready.


Watch zebrafish cells chase each other into patterns!

An amazing article from Ed Yong describes a new mechanism for pattern formation:

Coloured Cells Chase Each Other To Make A Fish’s Stripes

Zebrafish patterns aren’t just controlled by a chemical reaction-diffusion mechanism — the pigment cells actually chase each other! The different color cells sort themselves into stripes, spots, or other patterns depending on their relative speeds.

High-res

Underside of the leaf of the giant Amazon water lily. This particular specimen is a hybrid of Victoria amazonica and V. cruziana, and set a world record with its leaf —  2.65m (8’ 6½’’) across!

From The Living Rainforest, via I Fucking Love Science

nothing-without-science:

Facts About Fireflies

  • Fireflies talk to each other with light.

Fireflies emit light mostly to attract mates, although they also communicate for other reasons as well, such as to defend territory and warn predators away. In some firefly species, only one sex lights up. In most, however, both sexes glow; often the male will fly, while females will wait in trees, shrubs and grasses to spot an attractive male. If she finds one, she’ll signal it with a flash of her own.

  • Fireflies produce “cold light.”

Firefly lights are the most efficient lights in the world—100% of the energy is emitted as light. Compare that to an incandescent bulb, which emits 10% of its energy as light and the rest as heat, or a fluorescent bulb, which emits 90% of its energy as light. Because it produces no heat, scientists refer to firefly lights as “cold lights.”

In a firefly’s tail, you’ll find two chemicals: luciferase and luciferin. Luciferin is heat resistant, and it glows under the right conditions. Luciferase is an enzyme that triggers light emission. ATP, a chemical within the firefly’s body, converts to energy and initiates the glow. All living things, not just fireflies, contain ATP.

  • Firefly eggs glow.

Adult fireflies aren’t the only ones that glow. In some species, the larvae and even the eggs emit light. Firefly eggs have been observed to flash in response to stimulus such as gentle tapping or vibrations.

  • Fun Fact: Light Organs

The glow from fireflies or lightning bugs comes from photic organs, or organs that produce light.

  • Fun Fact: Making Light

Fireflies combine three special substances in their photic organs to make light. The three substances are:
luciferin (a pigment),
luciferase (an enzymatic catalyst),
and ATP (nucleotide that provides energy to cells).

  • How to Catch Lightning Bugs

Tips on how best to catch lightning bugs or fireflies. | More

  • Creating Firefly Habitats

What kind of habitat do fireflies like? Why do they like standing water? | More

Credit: Firefly.org

You are not an encapsulated bag of skin dragging around a dreary little ego. You are an evolutionary wonder, a trillion cells singing together in a vast chorale, an organism – environment, a symbiosis of cell and soul.

wetwareontologies:

A new project to create a life-like simulation of Caenohabditis elegans (pictured above), a roundworm. OpenWorm isn’t like these other initiatives; it’s a scrappy, open-source project that began with a tweet and that’s coordinated on Google Hangouts by scientists spread from San Diego to Russia. If it succeeds, it will have created a first in executable biology: a simulated animal using the principles of life to exist on a computer.

Images 1 and 2: Living pluteus larva of the sea biscuit Clypeaster subdepressus under polarized light microscopy. Only the skeleton remains visible. Photos by Bruno C. Vellutini (Wikimedia; Flickr); cc-by-sa

Image 3: Pluteus larva via ccNeLaS


Image 4: Developing pluteus larva. Via Wikimedia. Public domain

Image 5: Sea urchin development tattoo via The Loom

Caption: “Greetings! Here’s a pic of my science tat. I studied sea urchin development for my dissertation. Upon completion 2 yrs ago, I awarded myself this tat for my academic achievement. The tat is of a sea urchin egg, 2 cell embryo, blastula, gastrula, prism stage and pluteus larval stage. Or as my friend’s say, an orange developing into an Alien face-grabber.”

Actinotroch of Phoronis vancouverensis

From Invertebrate Embryology blog

Caption: “These pictures are stacks of confocal images of two different actinotroch larvae of the horseshoe worm Phoronis vancouverensis (Phylum Phoronida). P. vancouverensis is a rather inconspicuous phoronid which lives in small (a few centimeters long) muddy tubes in clumps, attached to some sort of hard substratum (a rock, a floating dock) often in somewhat muddy surroundings. This species broods its larvae in the crown of tentacles, called the lophophore. I gently shook the larvae out of the lophophore of an adult and prepared them for confocal microscopy with my students while teaching the Comparative Embryology course at the Friday Harbor Labs in the Summer 2007.

We preserved the larvae and stained them with fluorescent phallodin (a toxin, derived from the deathcap mushroom Amanita phalloides), which binds to filamentous actin. Muscles are highlighted because they are full of actin, a protein which enables cellular contractility. So, most of what you see on these pictures are muscle fibers. There is also quite a bit of actin in the cell cortex (the region of the cytoplasm adjacent to the plasma membrane). So, the outlines of epidermal cells are often also labeled with phalloidin.”

rhamphotheca:

For such tiny animals, Syllidae really get around.

These polychaete worms, most only a few millimeters long, are found from the intertidal to the deep sea. The over 200 species of Syllids, and potentially many more not yet recognized, are keeping some molecular biologists very busy. 133 species from 5 continents have DNA barcodes already, and our colleagues at the Moorea Biocode project just keep finding more, just waiting to be identified, or classified as new species.

More Syllids from Moorea here.

(via: Encyclopedia of Life)

The atoms come into my brain, dance a dance, and then go out — there are always new atoms, but always doing the same dance, remembering what the dance was yesterday.

Quote in context:

“For instance, the scientific article may say, “The radioactive phosphorus content of the cerebrum of the rat decreases to one-half in a period of two weeks.” Now what does that mean? It means that the phosphorus that is in the brain of a rat — and also in mine, and yours — is not the same phosphorus as it was two weeks ago. It means the atoms that are in the brain are being replaced: the ones that were there before have gone away. So what is this mind of ours: what are these atoms with consciousness? Last week’s potatoes! They now can remember what was going on in my mind a year ago — a mind which has long ago been replaced. To note that the thing I call my individuality is only a pattern or dance, that is what it means when one discovers how long it takes for the atoms of the brain to be replaced by other atoms. The atoms come into my brain, dance a dance, and then go out — there are always new atoms, but always doing the same dance, remembering what the dance was yesterday.”

Richard Feynman, “The Value of Science” (speech at NAS meeting, 1955)
reprinted in The Pleasure of Finding Things Out: The Best Short
Works of Richard P. Feynman
 (Jeffrey Robbins, ed., 1999)

This is a Bryozoan statoblast. It is a cyst that can survive over the winter and begin a new Bryozoan colony when conditions permit. The little anchor shaped hooks really cling to things and allow the statoblast to hitch a ride on vegatation or animals. ” Photos by Charles Krebs

ohscience:

Bryozoan Statoblast (diminutive aquatic animal of the phylum Bryozoa) (10x)

“Survival pod” of a bryozoan colony: http://en.wikipedia.org/wiki/Bryozoa#Reproduction_and_life_cycles

“Phylactolaemates also reproduce asexually by a method that enables a colony’s lineage to survive the variable and uncertain conditions of freshwater environments.[16] Throughout summer and autumn they produce disc-shaped statoblasts, masses of cells that function as “survival pods” rather like the gemmules of sponges.[6] Statoblasts form on the funiculus connected to the parent’s gut, which nourishes them.[16] As they grow, statoblasts develop protective bivalve-like shells made of chitin. When they mature, some statoblasts stick to the parent colony, some fall to the bottom (“sessoblasts”), some contain air spaces that enable them to float (“floatoblasts”),[6] and some remain in the parent’s cystid to re-build the colony if it dies.[16] Statoblasts can remain dormant for considerable periods, and while dormant can survive harsh conditions such as freezing and desiccation. They can be transported across long distances by animals, floating vegetation, currents[6] and winds,[16] and even in the guts of larger animals.[64] When conditions improve, the valves of the shell separate and the cells inside develop into a zooid that tries to form a new colony. Plumatella emarginata produces both “sessoblasts”, which enable the lineage to control a good territory even if hard times decimate the parent colonies, and “floatoblasts”, which spread to new sites. New colonies of Plumatella repens produce mainly “sessoblasts” while mature ones switch to “floatoblasts”.[61] A study estimated that one group of colonies in a patch measuring 1 square metre (11 sq ft) produced 800,000 statoblasts.[6]

Image 1: A dish of millipedes under UV light. Most of the ones fluorescing in blue are Semionellus placidus, while the two fluorescing red are Pseudopolydesmus serratus. Red fluorescence under UV hasn’t been reported before in arthropods, to my knowledge.”

Photos by Derek Hennen. Check out his blog post for more field notes and details on identification!

Image 2: Semionellus placidus, photo by Derek Hennen (source)