Tuesday, February 3, 2009

Not a spider – Not a Scorpion
This strange animal is called “Tailless Whip Scorpion”. This spider like animal is famous for their long, whip like front legs. Actually these tailless whip scorpions are neither true scorpions nor true spiders, but resemble a cross between the two. They live in humid habitat and prefer to hide under cavities of large tree roots and under the rocks. They prefer to hunt in night and rests in days. There are around 70 species worldwide.
The body of most tailless whip scorpion is around 2 inches long but the front leg pair is extremely long; up to 10 inches in few species. The tailless whips scorpion has one pair of eyes in the front side and three pairs of eyes on the side of head. The long, feeler-like front legs are important sensory organs for hunting and orientation at night. The tailless whip scorpion walks sideways with these legs leading the ways. The leg-like mouthparts are stout, spiny and used to capture and hold insect prey while it is ton by the fangs. Whip Scorpions are purely nocturnal hunters feeding mostly on insects such as cockroaches, grasshoppers and sometimes on centipedes. These are not at all venomous for human. Although these animals may look extremely dangerous and frightening, they are perfectly harmless and very shy.
Mating involves a brief courtship which begins with the male holding the females forelegs in his forelegs with their tips and walking backwards until the female raises her abdomen. The pregnant female digs a special burrow with a larger area at the end, when the eggs are laid they are inside a special membrane that prevents them from drying out. The female remains in the end of her burrow guarding the eggs. When the eggs hatch the young are white and look nothing like their mother, they climb onto her back and attach themselves there with special suckers. After a while they moult and the creature which now emerges looks like a miniature Whip Scorpion. After first moult they leave their mother. The young are slow growing and they gain maturity around the age of three years.
Yuwaraj Gurjar.http://www.yuwarajgurjar.com/
Whitenosed Bushfrog.
Frogs are members of the class called Amphibia. Amphibians are cold-blooded vertebrate animals. They differ from reptiles in that they lack scales and generally return to water to breed. Amphibians together with reptiles make up a larger group called Herps. The study of reptiles and amphibians is called Herpetology. Herp comes from the Greek word herpeton, which basically means "creepy crawly things that move about on their bellies."
Most amphibians lack scales on their skin, and it is usually smooth. Mucous and granular glands are present in the skin. Skin helps in oxygen uptake and release of carbon dioxide from the surrounding environment. Due to permeable nature of skin, water readily evaporates from the skin and dehydrates the amphibians easily. Hence they tend to restrict their activity only to high humidity and low wind periods to avoid evaporation stress. One can probably find more amphibians in moist environments and they are active during nights. Amphibians in the dry region tend to absorb water through skin from moist soils. Amphibians can change their skin color according the surrounding environment. Amphibians use gills, lungs and skin for the respiratory purposes.
Asian tree frogs are most closely related to true frogs (Ranidae) but seem to be the ecological equivalents of New World hylids by being arboreal and having enlarged toe disks at the ends of the fingers to aid in climbing. Most Asian tree frogs have large eyes with horizontal pupils and dorsal coloration ranging from green to brown and gray to black and white. Many have flash coloration (bright, patterned colors) on the inner thighs, which confuse predators when the frog leaps away and exposes these areas, thus distorting the frogs overall body pattern to the predator. There are members in the family Rhacophorous with extensive webbing that are able to glide by extending their limbs out as they jump, thus serving to increase their surface area. These species are arboreal, with strong jumping skills. This particular frog is Philautus waynadensis, one of the widely distributed and a common frog in the Western Ghats. In the past this species was referred to as Philautus leucorhinus. It is commonly called whitenosed bushfrog. It is endemic bushfrog with lower risk of extinction. Among the leaf frogs, eggs are usually deposited on leaves above ponds, where mothers keep them wet by urinating on them. Hatchlings fall into the water below.
Yuwaraj Gurjar.http://www.yuwarajgurjar.com/

Insect Orchestra
In early monsoon our forests are full with insect orchestras. The loudest instrumentalist in the animal world is by the insects. They do not have ears and have some hearing organs, but some species have developed remarkable efficient ways of producing sound as well as receiving it. It is nearly always the male that is equipped with the sound making equipment and thus he must make the first moves in courtship game.
The synchronized screeching of cicadas fills the air and is often painfully clear. The cicada song is so loud that it can sometimes be heard up to one kilometer away. When ready to mate, the male cicada positions himself high up in a tree and begins calling loudly to attract the mate. His song sparks off a chain reaction and suddenly all the males in the area will also burst into song. The sound of so many males seeking her attention quite overwhelms the female who flies right into the middle of this singing orchestra. Of course soon she finds her best male and they start for the new generation.
The cicadas, along with crickets and grasshoppers, are loudest and mist musical in the insect world and have remarkable complex ways of producing their unique sound. The male’s sound production mechanism consists of two hard plates called “tymbals” on either side of its thorax. By rapidly flexing strong muscles, the insect manages to buckle and unbuckle these plates to produce its characteristic ticking sound. What is more, the male cicada has a volume control over his songs – a special covering that acts as a damper when it is lowered. This, combined with a prodigiously fast output of ticks that can reach upto 1000 per second, gives cicada an instrumental voice of some versatility for charming a prospective mate. The sound is differentiating between the species and those cicadas able to produce more clicks per second can vary their songs to make them distinct from other varieties. In addition to this cicadas can, by raising and lowering a cover over the tymbal, make their song louder or quieter.
Yuwaraj Gurjar http://www.yuwarajgurjar.com/

Pit Vipers with “Sixth” sense.
Some snakes have infrared vision also called “heat vision,” the infrared rays, which have longer wavelengths than those of visible light, signify the presence of warm-blooded prey in 3 dimensions, which helps snakes aim their attacks. Pit vipers possess this ability; have heat-sensitive membranes that can detect the difference in temperature between a moving prey - such as a running mouse.
The detection system, which consists of cavities located on each side of the head called “pit organs,” operates on a principle similar to that of a pinhole camera. A pinhole camera is a camera without a lens, where light from an image passes through a very small hole. Similarly, a pit organ’s aperture is about 1 mm—large enough to allow the snake to quickly detect moving prey. In pit vipers, which have only two pit holes (one in front of each eye), a block of about 1,600 sensory cells lie on a membrane which has a field of view of about 100 degrees. This means the snake’s brain would receive an image resolution of about 2.5 degrees for point like objects, such as eyes, which are one of the hottest points on mammals. This head of Bamboo pit viper shows a nostril, pit hole and eye (right to left). This is one of the poisonous snakes found near us. The Bamboo Pit Viper is a pale green snake with faint, uneven black patterns on the back. The head is wide and triangular, set on a thin delicate neck. Actually this type of head is found in all types of Vipers and is one of the identification keys. This snake’s eyes are with golden iris and a black vertical pupil. This snake prefers living in vines, bushes and bamboo. Bamboo Pit Viper are slow moving snake and nocturnal. They rely on camouflage for protection. Although slow to defend themselves, they are capable of fast strikes and bites if disturbed. The food of this snake consists small mammals like rodents, lizards, birds and frogs. The female give birth to 4 or 5 living young. This is also Viper specialty as other snakes lay eggs. These Bamboo Pit Vipers are small in size near about 75 to 80 cms in adults. Their venom is low in toxicity, so that bites are rarely serious.
Yuwaraj Gurjar.

Spider female guarding egg sac.
Female spiders are usually larger than the male as the physical demands and accompanying energy requirements to produce webs and broods, are far greater. The male is smaller because once mature, his only function is to mate. Where males are similar in size to the females, they are generally more slender, with longer legs. In some cases the male can be one thousandth of the weight of the female. In other cases, the male and female are so different that they may even appear to be different species where males of certain species mimic wasps or ants.
Once mature, the male abandons all usual activities such as web construction and prey capture and transforms into a sexual attractions. Spider courtship is hazardous for the male spiders. It requires planning ahead, a good strategy, knowing the whims of your future mate and in some cases, the ability to perform long, arduous routines to please her - sometimes at the risk of being eaten by her. Once he has located a mate, the male spider dare not make a false move as it would mean certain death so the female is approached cautiously.
As the eggs develop in the female, her abdomen enlarges. After a period varying from 1 week to several months after mating, the female lays her eggs in the safety of darkness. About 1000 eggs can be laid in 8-10 minutes. Some spiders only produce a few eggs while few species can produce up to 9000 eggs and only about 2% survive to maturity. Spider eggs are roughly spherical, and about 1 mm in diameter; they are laid in a compact mass and covered to a greater or lesser extent with silk, forming a sac. The eggs are variously colored, pale brown, pale yellow, pink, even bright green. Underfed females lay less eggs but the size depends upon the species. Some spiders produce more than one sac, but there is a tendency for fewer eggs in the later sacs. Most species however spin much more substantial cocoons or egg-sacs to hold the eggs safe. This is particularly necessary to species where the mother dies before the eggs hatch. But some wolf spiders however live to see their young hatch.
The tiny hairless and blind creature must wait a few days to moult into a more advanced stage, the larva, which has rudimentary eyes and a few hairs but lacks poison and the ability to spin silk. Both of these stages are unable to feed and they subsist off the yolk within them. After a short period, the larva moults into a nymph or spiderling which resembles the adult in general form. At this stage, some cannibalism may take place within the sac, and those spiderlings which are weak becomes meal for others.
Yuwaraj Gurjar.