Monday, September 10, 2007
The six-year-old snake came to the The World Aquarium in St Louis attention when its previous owner offered it for sale days after its birth.The aquarium paid $US15,000 ($A20,514), knowing full well that most two-headed snakes don't live more than a few months.
But she has survived and thrived. Two-and-a-half centimetres thick and 1.2 metres long, she is a healthy size for a rat snake. While her body is white, the heads have a reddish appearance.she has survived because, unlike some two-headed animals, both mouths are connected to the same stomach, Sonnenschein said.Van Wallach of Harvard University's Museum of Comparative Zoology said she should live an additional 10 to 15 years. And Sonnenschein said it's at a ripe age for breeding.The snake has been in the spotlight before.In 2004, a disgruntled City Museum worker stole We. Authorities found the snake in the garage of the man's home in Illinois.
This is the only one of its kind in the world as recorded up to date.
Posted by Anju Devanur at 11:44 AM
Sunday, September 9, 2007
Sometimes owners are curious if their snake is a male or female, but telling the difference is not a simple matter as male and female snakes look similar externally. However, with a bit of experience there are ways to tell, but these methods should be done by experienced keepers only. If you are a beginner and want to know the sex of your snake, please find an experienced keeper or vet to demonstrate for you, as the methods carry a risk of injury if done incorrectly.
Relevant Male Snake Anatomy:
Male snakes have a pair of hemipenes (sex organs) that normally sit (inverted) inside the snake from the cloaca down along the tail on either side of the snake's midline.
Since the sex organs are held internally, sexing visually is difficult, but there are visible clues. Because of the presence of the hemipenes, these visual clues relate to the shape and lenght of the tail:
* Male: tail thicker and longer than in females, and also tapers less evenly to the tip (thicker for a bit then suddenly thinning).
* Females: tail thinner and shorter than in males, and tapers smoothly, evenly and more quickly.
While the differences can be fairly notable when comparing snakes, it is more difficult if you don't have males and females side by side.
Probing a snake involves inserting a thin metal rod (probe) into the vent or cloaca. The probe can be inserted further in males due to the presence of the spaces in which the hemipenes sit. A visual demonstration of the method is shown nicely at PetClubUK. This method is best left to the pros because inserting the probe incorrectly can badly injure the snake.
In very young snakes, the hemipenes can often be visualized with a fairly simple maneuver called popping. A visual demonstration of popping can also be found at PetClubUK. It is recommended that you do not try this yourself either, though; if done incorrectly, the snake could be injured (or at best you might just get the sex wrong).
The correct identification of the sex of your snakes will play a key role if you wish to breed them. An experienced keeper will have more of an idea on what exactly to look for when determining the sex, however with the help of photographs I aim to give you a good idea on how to do this yourself.
The first method is to visually see a difference in tail size and structure. Males have two hemipenes which are stored next to each other at the base of the tail. Each hemipene is tucked into its own 'pocket'. The effect of this is quite simple, it makes the tail appear fatter for a longer distance, generally making the overall tail length longer also. A female's tail narrows right from the base, making it almost 'carrot' shaped. The exact shape and length varies from species to species, but generally, the male has a longer tail.
Some species of snake are even easier to identify the sex. In some boas and pythons, males have prominent 'spurs' either side of their cloaca. This however, is not a guaranteed method in many species, as females too have spurs.
The second method is by use of a probe. A small, rounded metal rod can be inserted into the tail through the cloaca into the two 'pockets' either side of the base of the tail. The probe will penetrate farther into the male, whereas the female will only probe just a few scale lengths. This method should be carried out only by experienced keepers; it is a dangerous task if wrongly executed. Minimal force is needed for the probe to penetrate, yet it is a known mistake for people to apply too much pressure, resulting in the rupture of a female's scent glands. A lubricant must be used on the probe, Vaseline or KY Jelly are common substances to be used in this manner.
Popping a juvenile corn snake.The third method can be used on juvenile snakes. It is referred to as 'popping', which involves manually manipulating the hemipenes out of the male snake, while a female will slightly evert her scent glands. This method works better with younger snakes, directly after hatching is the time to obtain best results. At this age, the snake has not developed much muscle tone, making it relatively easy to force the hemipenes from the pockets.
Right Picture: Author 'popping' a male juvenile corn snake. The hemipenes are clearly visible.
I will explain how to do this if you are right handed like me. With your left hand, hold the body of the snake upside down in such a manner that the cloaca is held above the level of the rest of the body. With your right hand, pull the tail downwards slightly, and have your thumb resting approximately 2cm away from the cloaca. Gently roll and push your thumb down and across towards the cloaca, while at the same time bringing the tail upwards. This whole process sounds very complicated on paper, but I assure you it's easy once you get the hang of it. I highly recommend you to be taught this method by an experienced keeper before giving it a go yourself.
By Chris Jones
Director of PetClub UK Ltd.
Posted by Anju Devanur at 2:01 PM
Saturday, September 8, 2007
On a remote Florida island crawling with venomous snakes, a scientist believes he has discovered an unusual truce between predator and prey.
The tiny island of Seahorse Key on the central Gulf Coast is renowned among researchers for its teeming numbers of poisonous cottonmouth snakes.
"The population of cottonmouths on Seahorse Key is large and dense—I mean a lot of snakes," said Harvey Lillywhite, a University of Florida biologist who has been studying the island.
About 600 vipers slither around the 165-acre (67-hectare) island, Lillywhite estimates—in some areas with an average of 22 cottonmouths on every palm tree-covered acre. (See photos of the island's snakes.)
Scientists have long puzzled over how so many snakes can thrive on an island with no fresh water and only a scant number of mammals to prey upon.
The secret to the snakes' success, Lillywhite believes, is Seahorse Key's other inhabitants—tens of thousands of seabirds that nest there from spring to fall.
But the snakes aren't eating the birds, the scientist says—instead they live almost exclusively on the huge amounts of dead fish that the birds drop, vomit, and excrete every year.
"There's this disgusting carrion of fish that falls down for the snakes, and the snakes essentially scavenge on it," Lillywhite said.
In return for this fishy bounty, the cottonmouths not only refrain from eating the birds, the scientist added, they also seem to deter other would-be predators from raiding the nests.
The result is a win-win for both predator and prey that Lillywhite said he has not seen on any other island.
"There are a lot of island systems where there are birds and snakes. Of all the cases I know, the snakes are predators on the birds," he said. "At Seahorse Key, it's totally different. Here the snakes do not eat the birds, and the birds are providing food for [the snakes]. So it's a pretty cool system."
Seahorse Key is a centerpiece of the Cedar Key National Wildlife Refuge, a network of protected islands near the mouth of the Suwannee River (see an interactive map of the Suwannee River region).
The island is home to one of central Florida's biggest rookeries—a nesting site for more than a hundred bird species, including pelicans, ibis, and egrets.
Lillywhite believes it's no accident that the birds prefer this dry, viper-ridden island to other, more hospitable sites in the refuge.
"There's a lot of other nesting habitats for the birds, but the birds don't use them," he said. "They come to Seahorse Key. Why is that? We think the key is the snakes."
To examine this theory, Lillywhite and colleagues began by mapping the locations of both bird nests and snakes. Results showed that most cottonmouths stayed close to the rookery, often directly under nests.
Even without the maps, the team was usually able to tell where snakes had been, Lillywhite said.
"The snakes, which are normally almost jet black, can be almost white, because they curl up under the bird rookery and get pooped on."
A coating of excrement may be a small price to pay, he added, because research so far has revealed that the snakes are getting a steady diet of predigested fish.
Lillywhite has seen cottonmouths foraging for fish firsthand, and has even seen baby snakes taking part in the regurgitated feast.
"I was with a faculty member showing him around [the island], and there was this wonderful example of a plop of half-digested fish," he said. "There were two babies and about four or five other [snakes] … that had been attracted to it. So babies actually may get into this system fairly early."
In addition to field observations, Lillywhite's team is studying chemical signals called isotopes in cottonmouth tissue to find clues to what the snakes are eating.
"We haven't analyzed all the data yet, but based on our observations and limited isotope data, we know that [the snakes] have been largely feeding on fish," Lillywhite said.
What his team has not found, he added, is any sign—from the field or in the lab—that the cottonmouths are preying on birds, no matter how young or defenseless.
"Sometimes chicks fall out of the nests for various reasons, so we see chicks on the ground. But the snakes aren't eating them," he said.
"I think [that's] probably [because the snakes] are full on fish. It's a simple way to look at it, but that seems to be the key."
Lillywhite stressed that his research is ongoing and his findings are "a progress report."
One of the remaining issues to explore, he said, is the degree of mutualism—or shared benefit—that the cottonmouths and seabirds derive from this distinctive dynamic.
Here, Lillywhite suggested, the key may be one of the island's smallest players: the brown rat.
The rats are an invasive species and are "notorious bird-nest predators," he said.
His team has found that cottonmouths near the rookery—while presumably full on fish—are eating enough of the rats to keep them at bay.
"What we have found is, where the cottonmouths are dense, there are fewer rats. And the snakes are largest in numbers where the birds are," he said. "So that's part of the mutualism."
Alan Savitzky is a snake biologist at Virginia's Old Dominion University who is not involved with Lillywhite's research.
"The association between cottonmouths and bird rookeries is unusual but not unique," he said.
"But the situation at Seahorse Key is very interesting because [there's] the deterrence of predators. So you have a mutualism of sorts in which there's a benefit to both species."
He and Lillywhite agreed that the findings on Seahorse Key, preliminary as they are, help burnish the cottonmouths' image as an indiscriminate predator.
"I think the real strength [of the research] is in revealing the flexibility of what we normally regard as rather stereotyped predators," Savitzky said.
"It also suggests that there's probably a greater diversity of interactions between predator and prey across the landscape than we normally recognize."
For Lillywhite, the findings highlight the snakes' crucial role in a vital Gulf Coast ecosystem.
"[The cottonmouths] actually are an important, integral part of the system and probably are the reason that the birds keep nesting—and do so successfully—on Seahorse Key," he said.
"This is unusual, but kind of cool, PR for the lowly snake."
Posted by Anju Devanur at 12:16 PM
In the picture you can see a Sea snake scavenging on dead fish, the most unusual behavior of the snakes. Although it is widely known that most species of snakes readily accept carrion in captivity, the notion of scavenging by wild snakes historically has been rejected or ignored. Herein, we review the literature describing instances of scavenging by snakes and consider the implications of carrion use on their ecology. Thirty-nine published accounts yielded 50 observations of scavenging by snakes (43 from field observations and seven from laboratory studies). Thirty-five species from five families were represented, but pitvipers and piscivorous snakes were represented more frequently than other groups. Scavenged material varied widely and included rodents, birds, fish, frogs, and snakes. Olfaction appears to be the overriding sensory modality used for carrion detection. Some species may use scavenging as a deliberate feeding strategy that supplements their regular modes of prey acquisition. Additional knowledge of the scavenging behavior of snakes should provide new insights into the fundamentals of the ecology of snakes.
Posted by Anju Devanur at 12:12 PM
Snakes are probably the most misunderstood, and most illogically feared creatures on the planet. Of the 2,200-plus species of snakes in the world, fewer than 20 percent are venomous. People have an instinctual fear of snakes that stems back for thousands of years. It probably started out as a survival instinct, when there was no literature or way of telling which snakes were harmful or not. On the other hand, biblical literature has encouraged us to fear snakes for an entirely different reason. Other people simply misunderstand snakes, thinking that they are slimy, nasty creatures.
The first thing to know about snakes is that any non-venomous snake will only bite you for 3 reasons. First, if you smell like food. If you have recently handled a warm-blooded animal, such as mice, guinea pigs, even cats, the snake may smell that on you and mistake you for something edible. Second, if the snake feels you are a predator that is trying to harm it. Especially when reaching down towards a snake, the snake can misinterpret you for something trying to eat it. Thirdly, and the most likely reason non-venomous snakes bite, is simply because they are afraid. When given the choice between biting at you (the 5-6 foot tall giant that just stepped into it�s territory) or running away as fast as it can possibly slither�it will choose running away every time. If the snake however, feels cornered, or for whatever reason unable to hide, it will strike out at you, more as a warning to leave it alone than to actually do any damage.
Non-venomous snakes are usually very safe to handle, especially pet snakes or snakes that are used to being handled. Even most species of wild snakes that are non-venomous are perfectly able to be handled without fear of bites (the exception being water snakes and other naturally aggressive species). If you do try to handle a snake, be sure to move slowly, and edge your hand under the belly of the snake near the tail area. If you move suddenly, or from the top, it may mistake you for a predator. Once you have actually lifted the snake and are holding it, do not hold it by the tail, rather support it�s body loosely with your hands (keep a loose but firm grip, if you squeeze too hard it will likely injure the snake), and let the snake explore it�s way around your hands and arms. If the snake seems agitated, or goes into a strike position, it is best to slowly, but gently put the snake back.
You will find that snakes are not slimy, nor nasty in any way. However if they get frightened, they may defecate on you as a way of showing fear. If this happens, be sure to wash the area thoroughly with soap and hot water, as snakes do carry salmonella bacteria in their feces. You must also remember that snakes, while being beautiful and interesting to watch, simply aren�t the brightest creatures in the world, and have about the same thinking power as your average goldfish. Remember when you are holding a snake that it likely sees you as a very odd tree, and does not recognize you as a human being. Snakes react by instinct rather than thought, and as long as you keep this in mind, being around snakes is very easy to do as well as being interesting.
So how do you tell venomous and non-venomous snakes apart? There are several ways to tell, although some species of non-venomous snakes have adapted to be able to look like venomous snakes when they are afraid. If you are ever even slightly in doubt, leave the snake alone! As a general rule, venomous snakes have diamond or triangle shaped heads, instead of rounded heads that most non-venomous snakes have. Also, their eyes are elliptical like a cat�s eye instead of being round as well. Pit vipers have a telltale pit between the eye and the mouth. The pit, a heat-sensing organ, makes it possible for the snake to accurately strike a warm-blooded victim, even if the snake cannot see the victim. Of course rattlesnakes usually rattle, but this is not always the case. Some species of rattlesnakes have evolved without a rattle!
So now that you know more about snake behaviors and facts, I hope you will give snakes a chance. Not only are they fascinating to watch, but they serve a vital function in our ecosystem.
The North American racer snakes is commonly known as northern black racer. The scientific name of these snakes is coluber constrictor constrictor. Coluber is the Latin word and the meaning of the same is snake. Constrictor is again the Latin name which means together, or with. The other vernacular names of these snakes are plenty and are listed as follows. They are black runner, black racer, chicken snake, blue racer, hoop snake, green snake, black slick snake, horse racer, black true snake, white throat racer, and cow sucker.
The average length of the snake racer reptile will be from 35 inch to 60 inch. These snakes are relatively larger snakes and are black in color. The belly will be grey in color and the chin of the snake will be white. The body of the snake will be round and the scales that are found on the body will be smooth. The males and the females look alike and are very difficult to differentiate them by the appearance. The young ones will be dark grey patter against the brown body. The color of the Venter will be cream and can have black dots that are irregular. Brown or black dots that are small can be seen on the lateral to the dorsum.
Racer American snakes are often confused with rat snake. But the rat snake body will have bread loaf shape in cross section. The rat snakes have keeled scales which is absent in such snake that is found in most states in North America. The juvenile rat snakes will have pattern that resembles the checker board and eye jaw stripe on the belly portion. The juvenile rat snakes will have blotches that are irregular with posterior and anterior projections. Hog nosed snake black phase is also confused with the racer snake. But these hog nosed snakes are stocky and short when compared to black racer snakes.
The distribution of such wildly popular American snake are found in the Virginia and west part of the Blue Ridge Mountain. Other than southwest part of America, these snakes can be found in all other northern parts of America and south Canada. Relating food, these North American racer snakes are carnivores. These snake feed on frogs, skinks, chipmunks, small birds, squirrels, butterfly, larva of moth, mice etc. the juveniles feed on invertebrates while the adults feed on reptiles and rodents. North American racer snakes hold the prey tightly in the body loops and swallow them alive.
Posted by Anju Devanur at 11:53 AM
Wednesday, September 5, 2007
Monday, September 3, 2007
Mojave rattlesnake (Crotalus scutulatus scutulatus) venom: in vitro effect on platelets, fibrinolysis, and fibrinogen clotting
Corrigan JJ Jr, Jeter MA.
Department of Pediatrics, University of Arizona Health Sciences Center, Tucson 85724.
Rattlesnake envenomation commonly produce defects in the hemostatic mechanism. However, Mojave rattlesnake (Crotalus scutulatus scutulatus) envenomation has been reported not to cause a systemic bleeding diathesis. In this study, whole venom from the Mojave rattlesnake was tested in vitro for fibrinogen clotting activity, ability to induce platelet aggregation, and for fibrinolytic activity. The Mojave venom caused no fibrinogen clotting and it displayed very weak ability to cause platelet aggregation and fibrinolytic activity. These in vitro studies support the clinical observation that Mojave envenomation does not cause a coagulopathy.
PMID: 2238441 [PubMed - indexed for MEDLINE]
Mojave rattlesnake (Crotalus scutulatus scutulatus) identification
Mojave rattlesnake (Crotalus scutulatus scutulatus) identification has important diagnostic and therapeutic implications. Envenomation by certain populations of Mojave rattlesnakes may cause a different clinical presentation than that caused by other rattlesnakes. Specifically, Mojave rattlesnake envenomation may cause fewer local effects and more neurologic effects (including respiratory difficulty) than are typically seen after bites from other types of rattlesnake. Thus, it is useful for clinicians to distinguish the Mojave rattlesnake from other rattlesnakes in order to prevent underestimation of severe envenomation because of the lack of local tissue injury. Patients suspected to have been bitten by Mojave rattlesnakes may need more aggressive treatment with antivenin as well as more intensive supportive care. In addition, patients suspected to have been bitten by Mojave rattlesnakes should be closely monitored for an extended observation period, as venom effects may be delayed or prolonged. Mojave rattlesnakes may be particularly difficult to distinguish from Western Diamondback rattlesnakes (Crotalus atrox) because of their similarity in appearance and overlapping ranges. The purpose of this report is to provide clinicians with key characteristics which may assist in distinguishing Mojave rattlesnakes from Western Diamondback and other rattlesnakes.
PMID: 10347672 [PubMed - indexed for MEDLINE]