Saturday, February 28, 2009
Thursday, February 26, 2009
Deadly Creatures
Below are several examples from this gallery of Australia's deadliest creatures.
The cone snail is an underwater snail with a tooth-like stinger which acts like a harpoon. It has enough venom to kill a human as it paralyses the respiratory muscles. The cone snail's shell is pretty and colourful, so tourists often unknowingly pick them up:
The most venomous fish in the world, the stonefish is not aggressive, however its proximity to shores and ability to camouflage itself in coral makes it easy for people to accidentally touch or brush against. It has 13 dangerous spines and a dorsal fin, and when humans are stung it causes death to tissues:
The funnel-web spider sets up a trip-wire so it knows when prey is passing by, and its venom can kill a human in 15 minutes:
The blue-ringed octopus changes from a muddy orange colour to a vibrant blue when it strikes. It has venom 10,000 times more toxic than cyanide and can kill in 90 minutes. The size of a golf ball, its beak can penetrate a wetsuit:
See the full gallery here.
The cone snail is an underwater snail with a tooth-like stinger which acts like a harpoon. It has enough venom to kill a human as it paralyses the respiratory muscles. The cone snail's shell is pretty and colourful, so tourists often unknowingly pick them up:
The most venomous fish in the world, the stonefish is not aggressive, however its proximity to shores and ability to camouflage itself in coral makes it easy for people to accidentally touch or brush against. It has 13 dangerous spines and a dorsal fin, and when humans are stung it causes death to tissues:
The funnel-web spider sets up a trip-wire so it knows when prey is passing by, and its venom can kill a human in 15 minutes:
The blue-ringed octopus changes from a muddy orange colour to a vibrant blue when it strikes. It has venom 10,000 times more toxic than cyanide and can kill in 90 minutes. The size of a golf ball, its beak can penetrate a wetsuit:
See the full gallery here.
Wednesday, February 25, 2009
Fish with Tubular Eyes and Transparent Head
Researchers recently solved the half-century-old mystery of a fish with tubular eyes and a transparent head.
Ever since the "barreleye" fish Macropinna microstoma was first described in 1939, marine biologists have known that its tubular eyes are very good at collecting light. However, the eyes were believed to be fixed in place and seemed to provide only a "tunnel-vision" view of whatever was directly above the fish's head.
A paper shows that these unusual eyes can rotate within a transparent shield that covers the fish's head. This allows the barreleye to peer up at potential prey or focus forward to see what it is eating.
Below: The Macropinna microstoma has extremely light-sensitive eyes that can rotate within a transparent, fluid-filled shield on its head. The fish's tubular eyes are capped by bright green lenses. The eyes point upward (as shown here) when the fish is looking for food overhead. They point forward when the fish is feeding. The two spots above the fish's mouth are olfactory organs called nares, which are analogous to human nostrils.
Below: In this image, you can see that, although the barreleye is facing downward, its eyes are still looking straight up. This shot shows a barreleye that is about six inches long.
Below: This face-on view of a barreleye shows its transparent shield lit up by the lights of a remotely operated vehicle.
A video is also available from the original article here.
Ever since the "barreleye" fish Macropinna microstoma was first described in 1939, marine biologists have known that its tubular eyes are very good at collecting light. However, the eyes were believed to be fixed in place and seemed to provide only a "tunnel-vision" view of whatever was directly above the fish's head.
A paper shows that these unusual eyes can rotate within a transparent shield that covers the fish's head. This allows the barreleye to peer up at potential prey or focus forward to see what it is eating.
Below: The Macropinna microstoma has extremely light-sensitive eyes that can rotate within a transparent, fluid-filled shield on its head. The fish's tubular eyes are capped by bright green lenses. The eyes point upward (as shown here) when the fish is looking for food overhead. They point forward when the fish is feeding. The two spots above the fish's mouth are olfactory organs called nares, which are analogous to human nostrils.
Below: In this image, you can see that, although the barreleye is facing downward, its eyes are still looking straight up. This shot shows a barreleye that is about six inches long.
Below: This face-on view of a barreleye shows its transparent shield lit up by the lights of a remotely operated vehicle.
A video is also available from the original article here.
Tuesday, February 24, 2009
Fastest Flights in Nature: High-Speed Fungi Spore Discharges
Below are two examlpes of very high-speed videos of fungi launching their spores. A summary and link to the source study are provided below:
"In this study, we have used ultra-high-speed video cameras running at maximum frame rates of 250,000 fps to analyze the entire launch process in four species of fungi that grow on the dung of herbivores. For the first time we have direct measurements of launch speeds and empirical estimates of acceleration in these fungi. Launch speeds ranged from 2 to 25 m s−1 and corresponding accelerations of 20,000 to 180,000 g propelled spores over distances of up to 2.5 meters. In addition, quantitative spectroscopic methods were used to identify the organic and inorganic osmolytes responsible for generating the turgor pressures that drive spore discharge."
The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi:
More videos can be downloaded from here.
"In this study, we have used ultra-high-speed video cameras running at maximum frame rates of 250,000 fps to analyze the entire launch process in four species of fungi that grow on the dung of herbivores. For the first time we have direct measurements of launch speeds and empirical estimates of acceleration in these fungi. Launch speeds ranged from 2 to 25 m s−1 and corresponding accelerations of 20,000 to 180,000 g propelled spores over distances of up to 2.5 meters. In addition, quantitative spectroscopic methods were used to identify the organic and inorganic osmolytes responsible for generating the turgor pressures that drive spore discharge."
The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi:
More videos can be downloaded from here.
Thursday, February 19, 2009
Wednesday, February 18, 2009
Bizarre Creatures at Bottom of Arctic and Antarctic Seas
According to the Census of Marine Life, at least 235 types of cold-loving creatures have been discovered thriving at the bottom of the Arctic and Antarctic seas, puzzling scientists about how they got to both ends of the earth.
Until now, the warm tropics have been seen as a barrier keeping polar bears in the Arctic separate from penguins in the Antarctic. Only a few creatures have been known to live in both polar regions, such as long-migrating gray whales or Arctic terns.
Species living at both poles include cold-water worms, crustaceans, sea cucumbers and snail-like pteropods. They make up two percent of the 7,500 Antarctic and 5,500 Arctic animals known to date, out of a global total estimated at up to 250,000.
The findings, along with a discovery that the frigid seas teem with life, raise questions about where common polar species originated and how they wound up at both ends of the earth. Read the article to find out more.
Below: A shell-less pteropod or swimming snail, clione limacina, found in both Arctic and Antarctic waters.
Below: A bean-sized swimming snail, limacina helicina, which has crossed the tropics to live in both seas. The creature spins a mucus-net off its paddle-like foot-wings to trap algae and other small particles on which it feeds.
Below: A sand-flea hyperoche capucinus, a common predator swimming in polar waters.
Below: The nemertean pelagonemertes rollestoni has a yellow stomach that reaches out to feed all parts of the body.
Below: One of the Antarctic's ice fish, which can withstand temperatures that freeze the blood of all other types of fish.
For some previous blog posts about Antarctic and Arctic creatures see here, here, here, and here.
Until now, the warm tropics have been seen as a barrier keeping polar bears in the Arctic separate from penguins in the Antarctic. Only a few creatures have been known to live in both polar regions, such as long-migrating gray whales or Arctic terns.
Species living at both poles include cold-water worms, crustaceans, sea cucumbers and snail-like pteropods. They make up two percent of the 7,500 Antarctic and 5,500 Arctic animals known to date, out of a global total estimated at up to 250,000.
The findings, along with a discovery that the frigid seas teem with life, raise questions about where common polar species originated and how they wound up at both ends of the earth. Read the article to find out more.
Below: A shell-less pteropod or swimming snail, clione limacina, found in both Arctic and Antarctic waters.
Below: A bean-sized swimming snail, limacina helicina, which has crossed the tropics to live in both seas. The creature spins a mucus-net off its paddle-like foot-wings to trap algae and other small particles on which it feeds.
Below: A sand-flea hyperoche capucinus, a common predator swimming in polar waters.
Below: The nemertean pelagonemertes rollestoni has a yellow stomach that reaches out to feed all parts of the body.
Below: One of the Antarctic's ice fish, which can withstand temperatures that freeze the blood of all other types of fish.
For some previous blog posts about Antarctic and Arctic creatures see here, here, here, and here.
Monday, February 16, 2009
Genome of Common Cold Mapped
Researchers have solved the first step in treating the common cold, by mapping its entire genome, or genetic map.Technically known as the human rhinovirus infection, the common cold is responsible for half of all asthma attacks and is a factor in bronchitis, sinusitis, middle-ear infections and pneumonia.
Finding a cure for the common cold has been elusive. That's because the rhinovirus is so complex. Made up of at least 99 different strains, it can infect different people with different symptoms.
By mapping the genome of the common cold and assembling the results into a "family tree," scientists can see how the virus strains are related, as well as their differences.
Original article here.
Marine Biology Videos
Below are some selections from Wired's "10 Fantastic Marine Biology Videos." Several of the videos have been featured on this blog before. Here are a few new ones:
An interesting talk by David Gallo at TED conference, discussing all sorts of nifty underwater creatures:
An amazing example of the intelligence of Orcas as they team up while hunting:
The "Manatee Squash":
A massive school of jellyfish:
An interesting talk by David Gallo at TED conference, discussing all sorts of nifty underwater creatures:
An amazing example of the intelligence of Orcas as they team up while hunting:
The "Manatee Squash":
A massive school of jellyfish:
Skin Cells Reprogrammed as Heart Cells Beat in a Dish
Below is a video of skin cells that have been turned into heart tissue beating in a dish.
The tissue isn't ready for transplantation, but it's a moving proof-of-principle for induced pluripotency, which genetically reprograms adult cells into a near-embryonic state, capable of becoming almost any cell type.
In the last few years, induced pluripotency has been hailed as an uncontroversial alternative to embryonic stem cells, production of which requires the destruction of embryos.
However, reprogrammed cells aren't yet safe enough for clinical use — the mutations involved leave cells prone to forming tumors — but scientists are trying to make the mutations safer.
Original article here.
The tissue isn't ready for transplantation, but it's a moving proof-of-principle for induced pluripotency, which genetically reprograms adult cells into a near-embryonic state, capable of becoming almost any cell type.
In the last few years, induced pluripotency has been hailed as an uncontroversial alternative to embryonic stem cells, production of which requires the destruction of embryos.
However, reprogrammed cells aren't yet safe enough for clinical use — the mutations involved leave cells prone to forming tumors — but scientists are trying to make the mutations safer.
Original article here.
Footage of Oarfish
Below is rare footage of a living oarfish. Oarfish are large, elongated fish found in all temperate to tropical oceans, yet they are rarely seen:
Wednesday, February 11, 2009
Aerial Footage of Elusive Narwhals
Click the picture above or below to view neat footage of the elusive narwhal, best known for their unicorn-like tusks.
The whales were filmed during their summer migration as they navigated through cracks in Arctic sea ice. It is believed that this is the first such aerial footage of the narwhals.
Tuesday, February 10, 2009
Gut Bacteria Affect Almost Everything You Do
Bacteria living symbiotically inside human bodies may have an unexpectedly profound and wide ranging effect on basic biological functions such as development, reproduction and immunity.
In a comparison of blood from germ-free and regular mice, researchers found large differences in molecules that affect just about everything involved in living.
The human body contains 10 times more bacteria than human cells, with 50 trillion microbes living in the average digestive tract alone. The study of these internal bacteria is in its infancy: the Human Microbiome Project, launched to catalogue our bodies' bacterial inhabitants, started last October.
All these microbes are not just along for the ride, say scientists, but have co-evolved with human beings, providing important biochemical services in exchange for their home. Imbalances in gut bacteria have already been linked to obesity, cancer, asthma and a host of autoimmune diseases.
In a comparison of blood from germ-free and regular mice, researchers found large differences in molecules that affect just about everything involved in living.
The human body contains 10 times more bacteria than human cells, with 50 trillion microbes living in the average digestive tract alone. The study of these internal bacteria is in its infancy: the Human Microbiome Project, launched to catalogue our bodies' bacterial inhabitants, started last October.
All these microbes are not just along for the ride, say scientists, but have co-evolved with human beings, providing important biochemical services in exchange for their home. Imbalances in gut bacteria have already been linked to obesity, cancer, asthma and a host of autoimmune diseases.
Though marketers of what are known as probiotics have had some success in using bugs to treat allergies and irritable bowel disease, the causal links between bacteria and disease remain largely unspecified.
A critical first step in figuring them out is linking bacteria to cellular processes, known broadly as metabolites. The study of metabolites is also just getting off the ground. Some are cellular byproducts, while others are physiologically critical. But though the first draft of the human metabolome — the biochemical analog of the human genome — was completed just two years ago, scientists know it's important.
In the mouse comparison study, some metabolites were found only in germ-free mice. Others were found only in regular mice. Some were found in both, but in subtly different forms. The hodgepodge of results suggests that various bacteria break down, produce or otherwise tweak biochemicals.
A critical first step in figuring them out is linking bacteria to cellular processes, known broadly as metabolites. The study of metabolites is also just getting off the ground. Some are cellular byproducts, while others are physiologically critical. But though the first draft of the human metabolome — the biochemical analog of the human genome — was completed just two years ago, scientists know it's important.
In the mouse comparison study, some metabolites were found only in germ-free mice. Others were found only in regular mice. Some were found in both, but in subtly different forms. The hodgepodge of results suggests that various bacteria break down, produce or otherwise tweak biochemicals.
The findings also suggest that gut bacteria could be involved not just in maintaining health and disease, but processing drugs — helping to explain, perhaps, why drugs affect people in different ways.
Original article here.
Original article here.
Monday, February 09, 2009
Five New Pygmy Seahorse Species Found
Several new species of seahorses have been discovered near coral reefs in the Red Sea and Indonesia. All five are less than an inch tall and are among the tiniest known vertebrates.
Walea pygmy seahorse, named after an island in central Sulawesi, Indonesia — the only place it has so far been found:
Debelius' pygmy seahorse, named after the underwater photographer who found this Red Sea inhabitant:
Severns's pygmy seahorse, named after a diver:
At under half an inch tall, Satomi's pygmy seahorse (named after a dive guide) is a strong contender for the world's smallest seahorse. With their tails stretched out straight, two Satomi's pygmy seahorses would fit head-to-head across the face of a penny. These miniscule seahorses from Indonesian reefs have been seen giving birth to tiny offspring, each about the size of a 12-point apostrophe:
Pontoh's pygmy seahorse, named after an Indonesian dive guide:
Original article here.
Walea pygmy seahorse, named after an island in central Sulawesi, Indonesia — the only place it has so far been found:
Debelius' pygmy seahorse, named after the underwater photographer who found this Red Sea inhabitant:
Severns's pygmy seahorse, named after a diver:
At under half an inch tall, Satomi's pygmy seahorse (named after a dive guide) is a strong contender for the world's smallest seahorse. With their tails stretched out straight, two Satomi's pygmy seahorses would fit head-to-head across the face of a penny. These miniscule seahorses from Indonesian reefs have been seen giving birth to tiny offspring, each about the size of a 12-point apostrophe:
Pontoh's pygmy seahorse, named after an Indonesian dive guide:
Original article here.
Saturday, February 07, 2009
Bird Fishing Like a Human
Below is a video of a bird who has learned how to fish using bread as bait.
Thursday, February 05, 2009
Indonesian Mimic Octopus
Below is an amazing video featuring the mimic octopus (Thaumoctopus mimicus).
This octopus is able to copy the physical likeness and movement of more than fifteen different species, including sea snakes, lionfish, flatfish, brittle stars, giant crabs, sea shells, stingrays, jellyfish, sea anemones, and mantis shrimp.
This animal is so intelligent that it is able to discern which dangerous sea creature to impersonate that will present the greatest threat to its current possible predator.
This octopus is able to copy the physical likeness and movement of more than fifteen different species, including sea snakes, lionfish, flatfish, brittle stars, giant crabs, sea shells, stingrays, jellyfish, sea anemones, and mantis shrimp.
This animal is so intelligent that it is able to discern which dangerous sea creature to impersonate that will present the greatest threat to its current possible predator.
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