In a new study, zebrafish display signs of fear upon smelling sugar which are identical to their reactions to the pheromones released by other injured fish. Now scientists are speculating that this study could not only hint at the chemical composition of these pheromones, but also the origin of fear in fish and humans.

kjmichalak:

It’s an elephant using a smartphone. Need I say more?

npr:

Rare Sighting Of Dashing, Two-Legged Hairy Sprinting Crab?

In latin it’s called Thaumoctopus mimicus, but I’d call it The Master. It’s Meryl Streep in octopus form. There are ocean animals that can change shape, imitate plants, rocks, flora, and I’ve blogged about some of them. But this octopus is special. It seems to study other creatures and then imitate them, copying their moves and their bodies. It can do sea snakes, lionfish, flatfish, giant crabs, sea shells, stingrays, jellyfish and weird beings that have no name, and maybe no earthly existence. Is it imagining? I don’t know, but no scientist has ever seen a shaggy sprinting bi-pedal crab — until our octopus decided to be one. -

This pram bug, an inch-long, translucent Phronima crustacean, may look cute, but it certainly packs a vicious punch. Upon catching their usual prey of a small marine animals called salps, females feast by utilizing their mouths and claws to devour the salp’s insides and then hollowing out the corpse. To add insult to injury, the female then proceeds to lay her eggs inside the victim’s body cavity to create a mobile, gelatinous nest for her young. (via)

This pram bug, an inch-long, translucent Phronima crustacean, may look cute, but it certainly packs a vicious punch. Upon catching their usual prey of a small marine animals called salps, females feast by utilizing their mouths and claws to devour the salp’s insides and then hollowing out the corpse. To add insult to injury, the female then proceeds to lay her eggs inside the victim’s body cavity to create a mobile, gelatinous nest for her young. (via)

Anglerfish

The anglerfish is so called because of its method of predation. This is the fish that goes fishing. It has a long, modified dorsal fin spine sprouting from the middle of its head that ends in a fleshy growth that can move and wiggle to resemble another animal. In some deep sea anglerfish this deadly bait can even emit light (a characteristic called bioluminescence). Passing predators who think they’ve found an easy meal only need to touch the bait to find out they’re the main course. Having been lured inside the anglerfish’s wide mouth, the long pointed teeth snap shut and the creature is devoured whole. There are more than 300 species of anglerfish worldwide. They are found in open water and on the sea bed. Some of the bottom dwellers have modified fins that let them walk along the ocean floor.

Anglerfish

The anglerfish is so called because of its method of predation. This is the fish that goes fishing. It has a long, modified dorsal fin spine sprouting from the middle of its head that ends in a fleshy growth that can move and wiggle to resemble another animal. In some deep sea anglerfish this deadly bait can even emit light (a characteristic called bioluminescence). Passing predators who think they’ve found an easy meal only need to touch the bait to find out they’re the main course. Having been lured inside the anglerfish’s wide mouth, the long pointed teeth snap shut and the creature is devoured whole. There are more than 300 species of anglerfish worldwide. They are found in open water and on the sea bed. Some of the bottom dwellers have modified fins that let them walk along the ocean floor.

Pictured here is a pharaoh cuttlefish in the Daymaniyat Islands Nature Reserve. It is releasing its plume of ink in defense due to being stabbed by a diver, since net fishing on these protected coral reefs is prohibited, but other methods are legal, such as fishing with traditional long-handled hooks. (via)

Pictured here is a pharaoh cuttlefish in the Daymaniyat Islands Nature Reserve. It is releasing its plume of ink in defense due to being stabbed by a diver, since net fishing on these protected coral reefs is prohibited, but other methods are legal, such as fishing with traditional long-handled hooks. (via)

An elephant seal must stay in his territory to defend it, which could mean months without eating, having to live on his blubber storage. Two fighting males use their weight and canine teeth against each other. The outcome is rarely fatal, and the defeated bull will flee; however, bulls can suffer severe tears and cuts. Males commonly vocalize with a coughing roar that serves in both individual recognition and size assessment. Conflicts between high ranking males are more often resolved with posturing and vocalizing than with physical contact.

Aestivation

Aestivation is a period of deep and prolonged sleep, or torpor, that occurs in the summer or dry season in response to heat and drought. Food can often be scarce at such times, so animals avoid using up hard won energy reserves by lowering their metabolic rate. This reduces the need for food and water during hard times, ensuring longer-term survival.

Aestivation

Aestivation is a period of deep and prolonged sleep, or torpor, that occurs in the summer or dry season in response to heat and drought. Food can often be scarce at such times, so animals avoid using up hard won energy reserves by lowering their metabolic rate. This reduces the need for food and water during hard times, ensuring longer-term survival.

Striking Male Fish Tail Distracts Some Females from Feeding

The males of certain species of fish have a yellow band on the tailfin. Females seem uncontrollably drawn to it — and sometimes, a new study suggests, that can be their downfall.
 
Pregnant females, it seems, can mistake the band for a tasty worm or a damselfly, becoming so distracted by the yellow that their foraging abilities are diminished. 
“You can imagine a female trying to feed on damselfly or worm, but a male passes by and she is distracted,” said Constantino Macías Garcia, a behavioral ecologist at the National Autonomous University of Mexico, who led the study. “The female doesn’t have interest in mating at this point but is attracted and instead loses a feeding opportunity.”
The yellow-banded species they studied all belong to a family of North American fish known as Goodeidae. Even in species where females have evolved to learn that the band is not food, they are still drawn to it, the researchers found. 
The researchers found that when plant material was available to the females, the effect of males’ being nearby was reduced, which hints that the ability to eat plants may have evolved over time. “We cannot say that it became herbivorous because it was costly to be responding all the time to the males,” Dr. Macías Garcia said. “But it is a likely explanation.”

Striking Male Fish Tail Distracts Some Females from Feeding

The males of certain species of fish have a yellow band on the tailfin. Females seem uncontrollably drawn to it — and sometimes, a new study suggests, that can be their downfall.

Pregnant females, it seems, can mistake the band for a tasty worm or a damselfly, becoming so distracted by the yellow that their foraging abilities are diminished. 

“You can imagine a female trying to feed on damselfly or worm, but a male passes by and she is distracted,” said Constantino Macías Garcia, a behavioral ecologist at the National Autonomous University of Mexico, who led the study. “The female doesn’t have interest in mating at this point but is attracted and instead loses a feeding opportunity.”

The yellow-banded species they studied all belong to a family of North American fish known as Goodeidae. Even in species where females have evolved to learn that the band is not food, they are still drawn to it, the researchers found. 

The researchers found that when plant material was available to the females, the effect of males’ being nearby was reduced, which hints that the ability to eat plants may have evolved over time. “We cannot say that it became herbivorous because it was costly to be responding all the time to the males,” Dr. Macías Garcia said. “But it is a likely explanation.”

A Squeaky Serenade
Some animals, like the peacock for instance, put on elaborate displays for their potential mates. Other species perform dance-like movements. What do mice do? They serenade their mates. 
Yet, it was already known that these mice had high pitched mating calls. However, one recent study slowed down recordings of these squeaks, revealing their surprisingly intricate nature. Each mouse has a different, distinctive “voice.” So distinctive that females can effectively detect, and thus avoid, the mating songs of their siblings, preventing incestual affairs. 
But what else do they look for in these songs? Researchers are unsure. However, the researchers did find that mice that have lived in laboratories for long periods of time are unable to match the “musical complexity” that is achievable by their wild counterparts, making them less desirable.
"It seems as though house mice might provide a new model organism for the study of song in animals," said co-author Dr. Dustin Penn "Who would have thought that?"

A Squeaky Serenade

Some animals, like the peacock for instance, put on elaborate displays for their potential mates. Other species perform dance-like movements. What do mice do? They serenade their mates. 

Yet, it was already known that these mice had high pitched mating calls. However, one recent study slowed down recordings of these squeaks, revealing their surprisingly intricate nature. Each mouse has a different, distinctive “voice.” So distinctive that females can effectively detect, and thus avoid, the mating songs of their siblings, preventing incestual affairs. 

But what else do they look for in these songs? Researchers are unsure. However, the researchers did find that mice that have lived in laboratories for long periods of time are unable to match the “musical complexity” that is achievable by their wild counterparts, making them less desirable.

"It seems as though house mice might provide a new model organism for the study of song in animals," said co-author Dr. Dustin Penn "Who would have thought that?"

Lizards May Become Smarter by Warming World

When the heat is on, lizards become smarter – potentially giving them a competitive edge as the world warms.
Previous research has shown that scincid lizards (Bassiana duperreyi) grow larger if their eggs are incubated at higher temperatures. Joshua Amiel and colleagues at the University of Sydney, Australia, wanted to see if bigger lizards also make better learners, so they incubated nine eggs in cold conditions – 8.5 to 23.5  °C – and 12 in warm conditions – 14.5 to 29.5 °C.
Once hatched, the lizards were put in plastic containers equipped with two hideouts, one blocked off with Plexiglass and the other fully accessible. The researchers, playing predators, scared the lizards by touching their tails with a paintbrush and recorded where the lizards went. After 16 trials, five of the nine cold-incubated lizards still headed for the inaccessible hideout. Just one of the 12 warm-incubated lizards made the same mistake.
"Climate change might not be so bad for these guys," says Amiel.
Elsewhere in the world, though, a warmer world is bad news for reptiles. It is thought to be responsible for a 12 per cent drop in the population of one group of Mexican lizards since 1975, and a 75 per cent decline in reptiles and amphibians in Costa Rica’s native forests since 1970.

Lizards May Become Smarter by Warming World

When the heat is on, lizards become smarter – potentially giving them a competitive edge as the world warms.

Previous research has shown that scincid lizards (Bassiana duperreyi) grow larger if their eggs are incubated at higher temperatures. Joshua Amiel and colleagues at the University of Sydney, Australia, wanted to see if bigger lizards also make better learners, so they incubated nine eggs in cold conditions – 8.5 to 23.5  °C – and 12 in warm conditions – 14.5 to 29.5 °C.

Once hatched, the lizards were put in plastic containers equipped with two hideouts, one blocked off with Plexiglass and the other fully accessible. The researchers, playing predators, scared the lizards by touching their tails with a paintbrush and recorded where the lizards went. After 16 trials, five of the nine cold-incubated lizards still headed for the inaccessible hideout. Just one of the 12 warm-incubated lizards made the same mistake.

"Climate change might not be so bad for these guys," says Amiel.

Elsewhere in the world, though, a warmer world is bad news for reptiles. It is thought to be responsible for a 12 per cent drop in the population of one group of Mexican lizards since 1975, and a 75 per cent decline in reptiles and amphibians in Costa Rica’s native forests since 1970.

Carbon Dioxide Encourages Risky Behavior in Clownfish
Carbon dioxide in the ocean acts like alcohol on fish, leaving them less able to judge risks and prone to losing their senses. The intoxication adds to the threats that global warming and ocean acidification pose to marine ecosystems.
Around 2.3 billion tonnes of human-caused CO2 emissions dissolve into the world’s oceans every year, turning the water more acidic.
Philip Munday and colleagues at James Cook University in Townsville, Queensland, Australia, have previously found that if you put reef fish into water with more CO2 than normal in it – similar to the levels expected in oceans by the end of the century – they become bolder and attracted to odours they would normally avoid, including those of predators andunfavourable habitats.
Munday and his colleague Göran Nilsson at the University of Oslo, Norway, have now discovered that CO2 leads to riskier behaviour by interfering with a neurotransmitter receptor called GABA-A.
The pair reared clownfish (Amphiprion percula) larvae in seawater with normal (450 microatmospheres) and elevated (900 microatmospheres) CO2 levels. When they reached adulthood, the fish were given a choice between a water stream containing the odour of common predators such as the rock cod (Cephalopholis cyanostigma) or a stream lacking predatory odours. Those reared in high levels of CO2 swam towards rock cod’s scent around 90 per cent of the time, whereas those that had enjoyed normal levels of CO2 avoided the predator’s scent more than 90 per cent of the time.

Carbon Dioxide Encourages Risky Behavior in Clownfish

Carbon dioxide in the ocean acts like alcohol on fish, leaving them less able to judge risks and prone to losing their senses. The intoxication adds to the threats that global warming and ocean acidification pose to marine ecosystems.

Around 2.3 billion tonnes of human-caused CO2 emissions dissolve into the world’s oceans every year, turning the water more acidic.

Philip Munday and colleagues at James Cook University in Townsville, Queensland, Australia, have previously found that if you put reef fish into water with more CO2 than normal in it – similar to the levels expected in oceans by the end of the century – they become bolder and attracted to odours they would normally avoid, including those of predators andunfavourable habitats.

Munday and his colleague Göran Nilsson at the University of Oslo, Norway, have now discovered that CO2 leads to riskier behaviour by interfering with a neurotransmitter receptor called GABA-A.

The pair reared clownfish (Amphiprion percula) larvae in seawater with normal (450 microatmospheres) and elevated (900 microatmospheres) CO2 levels. When they reached adulthood, the fish were given a choice between a water stream containing the odour of common predators such as the rock cod (Cephalopholis cyanostigma) or a stream lacking predatory odours. Those reared in high levels of CO2 swam towards rock cod’s scent around 90 per cent of the time, whereas those that had enjoyed normal levels of COavoided the predator’s scent more than 90 per cent of the time.