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A marine mollusc has eyes that the lenses are made of rock, aragonite.
Chitons are gastropod mollusks (as snails) living on the sea coast, in the intertidal zone. They are characterized by a shell composed of eight hinged plates that allow the animal to curl up in an emergency. In some species, these plates are pierced with hundreds of ocelli, “eyes primitive containing such a lens which was unknown. Daniel Speiser, University of California, Santa Barbara, and colleagues found that it is composed of a kind of rock, aragonite (calcium carbonate). Moreover, the vision of chiton appears more elaborate than previously thought.
Biologists are interested in chiton Acanthopleura granulata . Initially, analysis, including X-ray diffraction, revealed the rocky nature of the lenses of ocelli. It was a surprise, because most lenses are made from animal protein and chitin. To evaluate the vision, the researchers then subjected to various tests of chitons. They showed their black disks (0.35 to 10 centimeters in diameter) or, through density filters placed in front of the lamp, decreasing the ambient light in amounts equivalent to those due to the disks. The idea was to verify that snails are good and do not simply react to a drop in brightness. In fact, chitons not retreated into a ball in the presence of a disk of at least three centimeters in diameter. This corresponds to a human in sight in the sky of a disk 20 times larger than the Moon.
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By sensing the Earth’s magnetic field, turtles determine the latitude of their position, but also their longitude: a first in the animal world!
To identify the surface of the Earth, we must know the latitude and longitude of its position, we provide the current GPS. Previously, we determined the latitude by the stars, but longitude has long been a problem, especially for marine chronometers until the invention of performing in the late eighteenthe century. What animals migrate? Although several species sensitive to the intensity of the geomagnetic field (it varies from north to south) obtain information on their latitude in their wanderings, but we thought longitude away from the animal world. This is not the case. Indeed, Nathan Putman, University of North Carolina, United States, and colleagues have shown that loggerhead turtle (Caretta caretta) perceived longitude.
Biologists have captured newly hatched turtles in Florida and placed them in arenas where the magnetic conditions were reproduced in two areas (Puerto Rico and the islands of Cape Verde), located on their migration route across the Atlantic Ocean at the same latitude (20 ° N), but at different longitudes. They then observed what direction they were moving. The first swam toward the Northeast, the second to the Southeast. Turtles born just can not use their memory for their first journey, these observations show that animals have information on the longitude, but what kind?
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Unlike what we thought, octopus control the movements of their tentacles through their vision.
A simple gesture, grab a cup of coffee, for example, hides a very complex: First, your visual system tracks the object code, its position, then your brain via various signals, control your muscles coordinated movements that lead your hand to the handle, then the cup to your lips. To perform this action, an arm has several degrees of freedom at the shoulder, elbow, wrist … Therefore, how does an octopus has eight tentacles, each being sufficiently flexible (no framing) to allow an almost infinite number of degrees of freedom? The anatomy challenge turns into the visual control of movements, so that some biologists believed that the cephalopod was unprepared. The work of Tamar Gutnick, Hebrew University of Jerusalem, and colleagues contradict this idea.
They have placed a common octopus (Octopus vulgaris) in an aquarium and he proposed a transparent container shaped three-pointed star. The octopus could insert a tentacle through the center, via a tube, and then had a choice of three directions. In each experiment, food was placed randomly at one of the three ends and indicated by a black disk. Most octopuses have learned to associate the brand with the presence of food and headed directly to their members the right compartment. The use of vision was confirmed by lower performance with an opaque container.
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A regular cat hairball vomit or refuse to eat, you may be suffering from stress caused by changes in their environment, as suggested by the results of new research.
In a recent experiment conducted by experts from Ohio State University, both healthy and sick cats , to be subjected to drastic changes in your routine, refused food, vomited frequently and relieved themselves outside their litter box ( the box or tray with sand or sawdust in which certain domestic animals become accustomed to urinate and defecate when indoors).
The researchers documented behavior of that class in healthy cats and those suffering from feline interstitial cystitis, a chronic disease characterized by recurrent pain or discomfort in the bladder and often an urgent and frequent urination.
When cats were experiencing what was classified as “external unusual events,” such a significant change in feeding schedules or other home care, healthy cats were just as likely that patients exhibit loss of appetite and other features anomalous behavior described above. Both groups experienced the same number of abnormal behaviors of this kind in response to unusual situations, and both groups had a threefold increased risk of not doing so anomalous when his routines were altered significantly.
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In what is a finding that collapses decades of scientific theory about the reproduction of reptiles, a team of researchers from the University of North Carolina State has found a boa constrictor female (and perhaps many others) is capable of generating progeny ( if only female) with no male involvement.
And even more surprising: the finding shows that snakes result of this asexual reproduction have attributes that were thought impossible.
Litters of female offspring produced by the “superhembra” studies do not show any male influence, ie there is no genetic blueprint that one male was involved in the reproductive process. Moreover, all these female snakes kept the strange color recessive mutation from his mother.
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Royal jelly is certain to become queen bee larvae. A molecular mechanism explaining the role just described.
Large, slow moving, the queen of a colony of bees spend most of his life – four to five years – to lay eggs, coddled by his court. The workers, however, are small, agile, sterile and live only a few weeks, during which they are full of varied activities. However, the queen and the workers are sisters and genetically identical. How a single genome can produce individuals so different? Germano-Australian team has shed light on molecular mechanisms involved
We knew the key to these different fates is food. Larvae reared as future queens and queen in place (once it has eliminated its rivals) are fed only royal jelly. Other larvae, which become workers, are fed mainly honey and pollen.
In 2008, the team of Sylvain Foret and Ryszard Maleszka, Australian National University, Canberra, showed that the suppression of the synthesis of an enzyme, DNA methyl-transferase in larvae fed worker to become , makes them develop into fertile queens, reproducing the effects of royal jelly. This enzyme is necessary for the methylation of DNA, that is to say the addition of methyl groups to certain bases of this molecule (cytosine), royal jelly brings likely substances that inhibit this process, “said epigenetic .
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In nature, the female hare can design a new range of hares while it is still in gestation. One way to increase the reproductive success of the species.
“Among the various species of animals, it is the woman and the mare, who has already designed, most easily suffer a reconciliation again. In other species, females who are full fleeing males, except those of course are likely superfluous, as the female rabbit. Aristotle, in his History of Animals (-347 to -342) had already observed that hase the female hare (Lepus europaeus) is able to become pregnant while she is still big: it is simultaneously fetus ready to be born and a second litter of embryos. According to Herodotus, “only one in the animal kingdom, hase designs being full, and small are covered with hair in her abdomen while the other embryos are still smooth, others are fashioned in her womb, others are just designed. “ A superfluity (from Latin super, moreover, and fetare lay, design) that can make the most prolific hare and compensate for the widespread hunting of which he is the object, the Greek historian noted.
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fish was discovered in South Africa by an international team of researchers led by Bernd Kramer of the Institute of Zoology, University of Regensburg. Mr. Kramer , also a biologist at the South African Institute of Aquatic Biodiversity ( SAIAB ) [1 ] , made the discovery in the Cunene , a river of southern Africa , on the border between Namibia and Angola.
For some time now, it is known that the species of pike of the Nile, ” Hippopotamyrus ansorgii ” are actually a whole complex of species, that is to say a school of several species more or less similar ; and those of the Zambezi River in the Caprivi Strip differ for example greatly from those in Angola. Through their extensive study in the River Cunene , the one of the rivers cradle of this species , the team of scientists has identified a kind of pike that stands clearly in his anatomy of the six other forms of ” Hippopotamyrus ansorgii “already known.
Pike Nile have the capacity to produce and analyze an electrical current called discharge electric organ ( EOD ) with their bodies ” issuers ” they use to navigate , detect and connect . Electric shocks , however, are specific to each species , not just at the curve pulse but also the amplitude spectrum . For example, electric shocks of species originating in River Cunene differ greatly from those from the Zambezi River . Following these observations , the scientific team of Kramer has set a new species autonomous of pike Nile and gave it the name ” Hippopotamyrus longilateralis.
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A team including researchers at the Agency for Fisheries Research , Research Center for Agriculture , Forestry and Fisheries of Oita Prefecture and the Japanese University of Life Sciences and Veterinary Sciences has developed a diagnostic method based on biotechnology and intended to be used on farmed fish.
The hirame flounder (Paralichthys olivaceus ), thin , is a leading fish farming in Japan. Consumed particular form of sushi and sashimi, its taste is quite famous , and therefore , its price is quite high . However, farmers are losing a significant proportion of their stock each year due to diseases of the fish ( between 13 and 31 % loss over the period 2004-2008) . Part of the problem is that there are few vaccines against infections that affect the flounder hirame , another is that the classical method of diagnosis might be improved. Indeed , it is to take samples from the organs ( kidneys, spleen … ) and then to cultivate them for over 24 hours searching for a specific pathogen . Meanwhile , the infection spreads.
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For the first time, it has been scientifically proven that selective breeding of domestic dogs is not only radically transforming the appearance of these animals, but also is causing major changes in the canine brain.
According to the researchers, the brains of many breeds of short-nosed dogs have rotated forward as much as 15 degrees, while the brain region that controls odor, she has relocated.
The wide variations in the size and shape of the skull of the dog are the result of more than 12,000 breeding years in search of functional and aesthetic characteristics.
The discovery of this major reorganization of the canine brain makes us wonder about its impact on the dog’s behavior.
The team of Dr Michael Valenzuela, formed by researchers at the University of New South Wales, Australia, and the University of Sydney, used magnetic resonance imaging to examine the brains of a wide range of races. They found strong and independent correlation between the size and shape of the skull of a dog, and the rotation of the brain and olfactory lobe positioning.
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Chitons are gastropod mollusks (as snails) living on the sea coast, in the intertidal zone. They are characterized by a shell composed of eight hinged plates that allow the animal to curl up in an emergency. In some species, these plates are pierced with hundreds of ocelli, “eyes primitive containing such a lens which was unknown. Daniel Speiser, University of California, Santa Barbara, and colleagues found that it is composed of a kind of rock, aragonite (calcium carbonate). Moreover, the vision of chiton appears more elaborate than previously thought.
To identify the surface of the Earth, we must know the latitude and longitude of its position, we provide the current GPS. Previously, we determined the latitude by the stars, but longitude has long been a problem, especially for marine chronometers until the invention of performing in the late eighteenthe century. What animals migrate? Although several species sensitive to the intensity of the geomagnetic field (it varies from north to south) obtain information on their latitude in their wanderings, but we thought longitude away from the animal world. This is not the case. Indeed, Nathan Putman, University of North Carolina, United States, and colleagues have shown that loggerhead turtle (Caretta caretta) perceived longitude.
A simple gesture, grab a cup of coffee, for example, hides a very complex: First, your visual system tracks the object code, its position, then your brain via various signals, control your muscles coordinated movements that lead your hand to the handle, then the cup to your lips. To perform this action, an arm has several degrees of freedom at the shoulder, elbow, wrist … Therefore, how does an octopus has eight tentacles, each being sufficiently flexible (no framing) to allow an almost infinite number of degrees of freedom? The anatomy challenge turns into the visual control of movements, so that some biologists believed that the cephalopod was unprepared. The work of Tamar Gutnick, Hebrew University of Jerusalem, and colleagues contradict this idea.
And even more surprising: the finding shows that snakes result of this asexual reproduction have attributes that were thought impossible.
Large, slow moving, the queen of a colony of bees spend most of his life – four to five years – to lay eggs, coddled by his court. The workers, however, are small, agile, sterile and live only a few weeks, during which they are full of varied activities. However, the queen and the workers are sisters and genetically identical. How a single genome can produce individuals so different? Germano-Australian team has shed light on molecular mechanisms involved
“Among the various species of animals, it is the woman and the mare, who has already designed, most easily suffer a reconciliation again. In other species, females who are full fleeing males, except those of course are likely superfluous, as the female rabbit. Aristotle, in his History of Animals (-347 to -342) had already observed that hase the female hare (Lepus europaeus) is able to become pregnant while she is still big: it is simultaneously fetus ready to be born and a second litter of embryos. According to Herodotus, “only one in the animal kingdom, hase designs being full, and small are covered with hair in her abdomen while the other embryos are still smooth, others are fashioned in her womb, others are just designed. “ A superfluity (from Latin super, moreover, and fetare lay, design) that can make the most prolific hare and compensate for the widespread hunting of which he is the object, the Greek historian noted.
For some time now, it is known that the species of pike of the Nile, ” Hippopotamyrus ansorgii ” are actually a whole complex of species, that is to say a school of several species more or less similar ; and those of the Zambezi River in the Caprivi Strip differ for example greatly from those in Angola. Through their extensive study in the River Cunene , the one of the rivers cradle of this species , the team of scientists has identified a kind of pike that stands clearly in his anatomy of the six other forms of ” Hippopotamyrus ansorgii “already known.
The hirame flounder (Paralichthys olivaceus ), thin , is a leading fish farming in Japan. Consumed particular form of sushi and sashimi, its taste is quite famous , and therefore , its price is quite high . However, farmers are losing a significant proportion of their stock each year due to diseases of the fish ( between 13 and 31 % loss over the period 2004-2008) . Part of the problem is that there are few vaccines against infections that affect the flounder hirame , another is that the classical method of diagnosis might be improved. Indeed , it is to take samples from the organs ( kidneys, spleen … ) and then to cultivate them for over 24 hours searching for a specific pathogen . Meanwhile , the infection spreads.