Posts tagged Biology
Posts tagged Biology
Golden tortoise beetle [Charidotella sexpunctata] by Chime Tsetan
They can change color, looking initially like tiny jewels, or golden ladybugs, but can alter the reflectivity of the cuticle so the outer layers become clear, revealing a ladybug type of red coloring with black spots. This color change is accomplished by microscopic valves controlling the moisture levels under the shell.
So. frikkin. cool!
(i need this as a pet. - nerd)
Bubble Anemone | Entacmaea quadricolor
(by richard ling)
The Sea Swallow(Glaucus atlanticus)
Also known as the Blue Sea Slug, the Blue Glaucus, and the Blue Ocean Slug, this is a species of nudibranch (sea slugs.) It will typically grow up to 3cm in length with six “feathered” appendages. This species is pelagic: it lives in the open ocean. It floats upside-down using the ocean’s surface tension and a ventral gas sac. The Swallow utilizes counter shading: it’s dorsal side is silver grey, and it’s ventral side is striped with dark and pale blues. But the most interesting thing about Glaucus is its feeding habits… it is immune to the venomous sting of nematocysts of sea jellies. So, it feeds on the most venomous ones like the Portuguese Man of War (Physalia physalis) and other surface-dwelling organisms like Janthina janthina. Glaucus, once devouring the most dangerous parts of these organisms, selects the highest-quality stinging cells and stores them in their cnidosacs in the tips of their feather-like fingers.
Or, you could just say it’s a tiny blue water dragon.
The news that there are “colours” that you cannot see should not be new news to you. The idea that mixtures of colours based off the visible spectrum that you still cannot see may be however. Certain colours, such as pink, are mixtures of different wavelengths of light, but other colours that are mixtures simply cannot be perceived and sound a bit like a real life octarine. These are colours such as red-green and blue-yellow, which are not actually what you get when you mix the two, but really a reddish variety of green or a bluish yellow colour. So why can’t we see these colours? The answer lies in what are known as “opponent neurons” in the eye’s retina. When red is seen one type of these neurons will fire, which the brain sees as red, when green is seen the neuron is silent and this lack of signaling is perceived as green. Interestingly this is also the basis of Red-Green colour blindness. So although these colours actually exist, we cannot see them because we cannot have a neuron firing and not firing at the same time.
Weird. But interesting.
A 400-times magnified view of diatoms.
Image by Robert Berdan.
Using sea slugs as models, scientists someday may be able to design learning protocols that improve long-term memory formation in humans, a new study suggests.
The researchers used information about biochemical pathways in the brain of the sea slug Aplysia to design a computer model that identified the times when the mollusk’s brain is primed for learning. They tested the model by submitting the animals to a series of training sessions, involving electric shocks, and found that Aplysia experienced a significant increase in memory formation when the sessions were conducted during the peak periods predicted by the model.
The proof-of-principle study may someday help scientists discover ways to improve human memory, the researchers said.
“This is very impressive,” David Glanzman, a neurobiologist at the University of California Los Angeles, said of the study, in which he was not involved. “If someone had asked me ahead of time, ‘Are you going to be able to improve learning if you model these two pathways?’ I would have predicted no.”
Yes, I’m reblogging mostly for the picture, though the article is interesting to. I love nudibrachs (a name that sounds so much better than “sea slugs”,) but mostly I’m curious to know what those lovely little round blue things are.