Tuesday 23 August 2016

Golden Glitter Gecko



Like just about every other kind of reptile on the planet, there’s going to come a time when they start to shed their skin. Leopard Geckos however shed their skin all at once rather than in pieces or over time. It kind of comes off like a suit.

How often does it happen?

This will vary for certain ages and maturity level but it’s obviously going to happen a lot more with baby Geckos than it will with adults. Depending on the age and maturity of your Leopard Geckos, they can shed at different frequencies and there’s not really a set timer under which this is going to or when this should happen. If you want to get a decent idea of how often this is going to happen, then you can easily just watch your Gecko and track its growth progress. The quicker it’s growing, the more frequently that it’s going to shed.

How do you know when it’s going to happen?

As babies will often shed far more than adults, there’s one very easy and one very telltale sign that a Gecko is about to shed off its skin. When this is about to happen, you’ll notice that the colors of the Gecko get considerably duller and as the skin starts to separate from the body, it’ll start turning white just before it happens. When they do skin, Leopard Geckos tend to eat all of their skin in the process while they’re shedding. There are actually a couple of fundamental reasons as to why they do this.

When a Gecko sheds its skin, it has to expel a lot of energy to do and it’s kind of like getting a very rigorous workout for the animal. So what do you want to do after you do a hard and long work out? You more than likely want to eat something and the very skin it shed just happens to be right there after the work out is done. Besides, all that energy has to be put back into the body somehow and the skin is the easiest way to do so.

Also, this is a trick that most Geckos pick up from being out in the wild and is something that’s kind of an internal alarm for them, but when they’re out in the wild, they’re best bet to stay safe is to not leave any tracks, kind of like a Green Beret. So to do this, it’s easier to just eat the skin rather than trying to hide it and giving potential predators a clue as to where it has been and where it’s going. Some animals use smell to pick up prey and leaving the skin behind could give off smell to help it find the Gecko, this is why it’s essential for them to eat the skin.

Shedding is usually a very simple and relatively simple process but in rare occasions, they don’t have the humidity that’s required to perform the self-procedure. You should make sure they have adequate housing and humidity if you notice your Leopard Geckos are about to start shedding because if you don’t have an efficient cage setup to do so, they’re going to have issues. It’s always essential to make sure that a Gecko sheds all of its skin off to ensure that the humidity is perfect because if there’s still some skin hanging onto it that it couldn’t shed off, the humidity may be to blame.

Commonly when there’s a problem shedding, skin will stick to the toe of the Gecko and while this may not sound like a problem, down the road, the toe can become restricted and blood flow to the tow may be cut off causing it to lose a toe. Sure, your Gecko will live, but I assume you’d want all of your toes would you not?

High humidity is basically the most important thing that you want to provide your Geckos when they start to shed. Leopard Geckos will usually try to migrate or go to a moist hiding place anyways, when they are shedding or when they’re not shedding. Some of the most common ways to obtain a moist shelter is to use a container that’s plastic and a lot of people have stated that a plastic cottage cheese container worked the best for them. Everyone finds their own preferred container. Just remember to cut a hole large enough that it can fit in but not too large to where a lot of light can get in.

You can use mulch inside of the container if you’d like to provide some bedding to help and aid the moisture inside the container. Make sure that the bedding that you do use (if you use any at all) isn’t dripping wet and is just moist enough to be enjoyable for your Leopard Geckos.

Don’t be afraid to devote a hand to helping your Gecko shed its skin off; it’s not going to hurt you. If you notice some of the skin hasn’t come off the big toe or that you think some of the skin wasn’t successfully shredded off, then you can use the following method:

1) Find a nice, small and suitable plastic container that’s clean to place wet towels in. Again, you don’t want them to be dripping but went enough to get the job done. Make sure they’re warm as well, cold water will probably frighten the Gecko.
2) Put a top on top of the container and let the Gecko sit like that for half an hour or longer if you feel that it’s not humid enough.

Once you feel it’s humid enough, what should happen now is, it should be easy to remove the skin with a pair of tweezers, since there more than likely won’t be a lot of skin to peel off. If that wasn’t long enough, then feel free to give it another 30 minutes.

Source: Geckocare

Orb-weaver spider



Orb-weaver spiders or araneids are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields and forests. "Orb" was previously used in English to mean "circular",[2] hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs.[1]

The family is cosmopolitan, including many well-known large or brightly colored garden spiders. With around 3,100 species in 169 genera worldwide, Araneidae is the third-largest family of spiders (behind Salticidae and Linyphiidae).[1] Araneid webs are constructed in a stereotyped fashion. A framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets.

Orb-webs are also produced by members of other spider families. The large golden orb-weavers (Nephilidae) and the long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are closely related, being part of the superfamily Araneoidea. The cribellate or hackled orb-weavers (Uloboridae) belong to a different group of spiders. Their webs are strikingly similar, but use a different kind of sticky silk.

Web[edit]

Argiope sp. sitting on the stabilimentum at the center of the web

Spiderlings in the web near where they hatched

Close-up of the cephalothorax on Eriophora sp. (possibly E. heroine or E. pustuosa
Generally, orb-weaving spiders are three-clawed builders of flat webs with sticky spiral capture silk. The building of a web is an engineering feat, begun when the spider floats a line on the wind to another surface. The spider secures the line and then drops another line from the center, making a "Y". The rest of the scaffolding follows with many radii of nonsticky silk being constructed before a final spiral of sticky capture silk.

The third claw is used to walk on the nonsticky part of the web. Characteristically, the prey insect that blunders into the sticky lines is stunned by a quick bite, and then wrapped in silk. If the prey is a venomous insect, such as a wasp, wrapping may precede biting.


Many orb-weavers build a new web each day. Most orb-weavers tend to be active during the evening hours; they hide for most of the day. Generally, towards evening, the spider will consume the old web, rest for approximately an hour, then spin a new web in the same general location. Thus, the webs of orb-weavers are generally free of the accumulation of detritus common to other species, such as black widow spiders.


Some orb-weavers do not build webs at all. Members of the genera Mastophora in the Americas, Cladomelea in Africa, and Ordgarius in Australia produce sticky globules, which contain a pheromone analog. The globule is hung from a silken thread dangled by the spider from its front legs. The pheromone analog attracts male moths of only a few species. These get stuck on the globule and are reeled in to be eaten. Interestingly, both types of bolas spiders are highly camouflaged and difficult to locate.

The spiny orb-weaving spiders in the genera Gasteracantha and Micrathena look like plant seeds or thorns hanging in their orb-webs. Some species of Gasteracantha have very long, horn-like spines protruding from their abdomens.

One feature of the webs of some orb-weavers is the stabilimentum, a crisscross band of silk through the center of the web. It is found in a number of genera, but Argiope, the yellow and banded garden spiders of North America, is a prime example. The band has been hypothesized to be a lure for prey, a marker to warn birds away from the web, and a camouflage for the spider when it sits in the center of the web. However, recent research suggests the stabilimentum actually decreases the visibility of the silk to insects, thus making it harder for prey to avoid the web.[3] The orb-web consists of a frame and supporting radii overlaid with a sticky capture spiral, and the silks used by orb-weaver spiders have exceptional mechanical properties to withstand the impact of flying prey.[4]

During the Cretaceous, a radiation of angiosperm plants and their insect pollinators occurred. Fossil evidence shows that the orb web was in existence at this time, which permitted a concurrent radiation of the spider predators along with their insect prey.[5][6] The capacity of orb–webs to absorb the impact of flying prey led orbicularian spiders to become the dominant predators of aerial insects in many ecosystems.[7] Insects and spiders have comparable rates of diversification, suggesting they co-radiated, and the peak of this radiation occurred 100 Mya before the origin of angiosperms.[8] Vollrath and Selden (2007) make the bold proposition that insect evolution was driven less by flowering plants than by spider predation – particularly through orb webs – as a major selective force.

Most arachnid webs are vertical and the spiders usually hang with their head downward. A few webs, such as those of orb-weavers in the genus Metepiera have the orb hidden within a tangled space of web. Some Metepiera are semisocial and live in communal webs. In Mexico, such communal webs have been cut out of trees or bushes and used for living fly paper.[citation needed] In 2009, workers at a Baltimore Wastewater Treatment Plant called for help to deal with over 100 million orb-weaver spiders, living in a community that managed to spin a phenomenal web that covered some 4 acres of a building with spider densities in some areas reaching 35,176 spiders per cubic meter.[9]

Peucetia viridana


Peucetia viridana is a green colored spider with cephalothorax having brown spots. The head region has a few spines and the centre has deep fovea which is green in colour. The clypeus is long with two black lines extending from the base of the middle anterior eyes. The sternum is heart shaped, pointed behind and covered with pines and hair. The legs are long and strong covered with conspicuous black spots and black long spines. The abdomen is long, narrowing behind and covered with fine hair. A longitudinal deep brown line runs through the center of the abdomen with lateral branches.[2]


The females are about 10-12 mm in size and the males about 8–10 mm in size.

It is generally found on grass and low shrubs.


Jumping Spider - Salticidae


The jumping spider family (Salticidae) contains over 500 described genera and over 5,000 described species,[1] making it the largest family of spiders with about 13% of all species.[2] Jumping spiders have some of the best vision among arthropods and use it in courtship, hunting, and navigation. Although they normally move unobtrusively and fairly slowly, most species are capable of very agile jumps, notably when hunting, but sometimes in response to sudden threats or crossing long gaps. Both their book lungs and the tracheal system are well-developed, and they use both systems (bimodal breathing). Jumping spiders are generally recognized by their eye pattern. All jumping spiders have four pairs of eyes with one pair being their particularly large anterior median eyes.



Distinguishing characteristics

Salticidae male anterior and dorsal aspects, showing positions of eyes
Jumping spiders are among the easiest to distinguish from similar spider families because of the shape of the cephalothorax and their eye patterns. The families closest to Salticidae in general appearance are the Corinnidae (distinguished also by prominent spines on the back four legs), the Oxyopidae (the lynx spiders, distinguished by very prominent spines on all legs), and the Thomisidae (the crab spiders, distinguished by their front four legs, which are very long and powerful). None of these families however, has eyes that resemble those of the Salticidae. Conversely, the legs of jumping spiders are not covered with any very prominent spines. Their front four legs generally are larger than the hind four, but not as dramatically so as those of the crab spiders, nor are they held in the outstretched-arms attitude characteristic of the Thomisidae.[3] In spite of the length of their front legs, Salticidae depend on their rear legs for jumping. The generally larger front legs are used partly to assist in grasping prey,[4] and in some species, the front legs and pedipalps are used in species-recognition signalling.

The jumping spiders, unlike the other families, have faces that are roughly rectangular surfaces perpendicular to their direction of motion. In effect this means that their forward-looking, anterior eyes are on "flat faces", as shown in the photographs. Their eye pattern is the clearest single identifying characteristic. They have eight eyes, as illustrated.[3][4] Most diagnostic are the front row of four eyes, in which the anterior median pair are more dramatically prominent than any other spider eyes apart from the posterior median eyes of the Deinopidae. There is, however, a radical functional difference between the major (AME) eyes of Salticidae and the major (PME) eyes of the Deinopidae; the large posterior eyes of Deinopidae are adapted mainly to vision in dim light, whereas the large anterior eyes of Salticidae are adapted to detailed, three-dimensional vision for purposes of estimating the range, direction, and nature of potential prey, permitting the spider to direct its attacking leaps with great precision. The anterior lateral eyes, though large, are smaller than the AME and provide a wider forward field of vision.

The rear row of four eyes may be described as strongly bent, or as being rearranged into two rows, with two large posterior lateral eyes furthest back. They serve for lateral vision. The posterior median eyes also have been shifted out laterally, almost as far as the posterior lateral eyes. They are usually much smaller than the posterior lateral eyes and there is doubt about whether they are at all functional in many species.

The body length of jumping spiders generally range from 1 to 25 mm (0.04–0.98 in).[3][5] The largest is Hyllus giganteus,[5] while other genera with relatively large species include Phidippus, Philaeus and Plexippus.[6]

In addition to using their silk for safety lines while jumping, they also build silken "pup tents", where they shelter from bad weather and sleep at night. They molt within these shelters, build and store egg cases within them, and also spend the winter in them.[7]

Habitat
Jumping spiders live in a variety of habitats. Tropical forests harbor the most species, but they are also found in temperate forests, scrub lands, deserts, intertidal zones, and mountainous regions. Euophrys omnisuperstes is the species reported to have been collected at the highest elevation, on the slopes of Mount Everest
Vision[edit]


The eight eyes of a Telamonia dimidiata located near the front

Marpissa muscosa, female
Jumping spiders have four pairs of eyes; three secondary pairs that are fixed and a principal pair that is movable.

The posterior median eyes (PME) are vestigial in many species, but in some primitive sub-families they are comparable in size with the other secondary eyes and help to detect motion.[9] While unable to form images, it is suspected that the reduced pair of eyes has a role similar to that of insect ocelli by receiving light from the sky. The photoreceptors in the other secondary pairs are almost exclusively greensensitive, but the PME have two visual pigments different from that in all the other eyes, sensitive to blue and UV-light.[10]

The posterior lateral eyes (PLE) are wide-angle motion detectors which sense motions from the side and behind. Combined with the other eyes, it gives the spider a near 360-degree view of the world.

The anterior lateral eyes (ALE) have the best visual acuity and are the most complex of the secondary eyes.[11] It has been shown that they are able to distinguish some details as well, and without them no "looming response" will be triggered by motion.[12] Even with all the other pairs covered, jumping spiders in a study could still detect, stalk and attack flies, using the anterior lateral eyes only, which are also sufficiently widely spaced to provide stereoscopic vision.[13]

The anterior median eyes (AME) have very good vision. This pair of eyes is built like a telescopic tube with a corneal lens in the front and a second lens in the back that focus images onto a four-layered retina, a narrow boomerang-shaped strip oriented vertically.[14][15] Physiological experiments have shown they may have up to four different kinds of receptor cells, with different absorption spectra, giving them the possibility of up to tetrachromatic color vision, with sensitivity extending into the ultraviolet range. As the eyes are too close together to allow depth perception, and the animals do not make use of motion parallax, they have evolved a method called image defocus instead. Of the four photoreceptor layers in the retina, the first two closest to the surface contain ultraviolet-sensitive pigments while the two deepest contain green-sensitive pigments. The incoming green light is only focused on the deepest layer, while the other one receives defocused or fuzzy images. By measuring the amount of defocus from the fuzzy layer, it is possible to calculate the distance to the objects in front of them.[16][17] In addition to receptor cells, also red filters have been detected, located in front of the cells that normally register green light.[18] It seems that all salticids, regardless of whether they have two, three, or four kinds of color receptors, are highly sensitive to UV light.[19] Some species (for example, Cosmophasis umbratica) are highly dimorphic in the UV spectrum, suggesting a role in sexual signaling (Lim & Li, 2005). Color discrimination has been demonstrated in behavioral experiments.

The principal, anterior median, eyes have high resolution (11 min visual angle),[20] but the field of vision is narrow, from 2 to 5°. The central region of the retina, where acuity is highest, is no more than six or seven receptor rows wide. However, the eye can scan objects off the direct axis of vision. As the lens is attached to the carapace, the eye's scanning movements are restricted to its retina through a complicated pattern of translations and rotations.[21] This dynamic adjustment is a means of compensation for the narrowness of the static field of vision. It is analogous to the way most primates move their eyes to focus images of interest onto the fovea centralis. Such movements within the jumping spider's eyes are visible from outside when the attention of the spider is directed to various targets.[22]

Behavior
Jumping spiders are generally diurnal, active hunters. Their well-developed internal hydraulic system extends their limbs by altering the pressure of body fluid (hemolymph) within them. This enables the spiders to jump without having large muscular legs like a grasshopper. Most jumping spiders can jump several times the length of their bodies. When a jumping spider is moving from place to place, and especially just before it jumps, it tethers a filament of silk (or 'dragline') to whatever it is standing on to protect itself if the jump should fail.[7] Should it fall, for example if the prey shakes it off, it climbs back up the silk tether. Some species, such as Portia, will actually let themselves down to attack prey such as a web spider apparently secure in the middle of its web. Like many other spiders that leave practically continuous silk trails, jumping spiders impregnate the silk line with pheromones that play a role in social and reproductive communication, and possibly in navigation.

Certain species of jumping spiders have been shown by experiment to be capable of learning, recognizing, and remembering colors, and adapting their hunting behavior accordingly.[23]

Hunting
The hunting behaviour of the Salticidae is confusingly varied compared to that of most spiders in other families.[24] Salticids hunt diurnally as a rule, which is consistent with their highly developed visual system. When it detects potential prey, a jumping spider typically begins orienting itself by swivelling its cephalothorax to bring the anterior median eyes to bear. It then moves its abdomen into line with its cephalothorax. After that, it might spend some time inspecting the object of its attention and determining whether a camouflaged or doubtful item of prey is promising, before it starts to stalk slowly forward. When close enough, the spider pauses to attach a dragline, then springs onto the prey.

There are, though, many variations on the theme and many surprising aspects. For one thing, salticids do not necessarily follow a straight path in approaching prey. They may follow a circuitous course, sometimes even a course that takes the hunter through regions from which the prey is not visible. Such complex adaptive behaviour is hard to reconcile with an organism that has such a tiny brain, but some jumping spiders, in particular some species of Portia, can negotiate long detours from one bush down to the ground, then up the stem of another bush to capture a prey item on a particular leaf. Such behaviour still is the subject of research.[24]

Some salticid species are continually on the move, stopping periodically to look around for prey, which they then stalk immediately. Others spend more time scanning their surroundings from one position, actively stalking any prey they detect. Members of the genus Phaeacius take that strategy to extremes; they sit on a tree trunk, facing downwards and rarely do any stalking, but simply lunge down on any prey items that pass close before them.[24]

Some Salticidae specialise in particular classes of prey. Ants comprise one such class. Most spiders, including most salticids, avoid worker ants, but several species not only eat them as a primary item in their diets, but also employ specialised attack techniques — Corythalia canosa for example, circles round to the front of the ant and grabs it over the back of its head. Such myrmecophagous species, however, will not necessarily refuse other prey items, and will routinely catch flies and similar prey in the usual salticid fashion, without the special precautions they apply in hunting dangerous prey such as ants. Ants offer the advantages of being plentiful prey items for which there is little competition from other predators, but it remains profitable to catch less hazardous prey when it presents itself.[24]

Some of the most surprising hunting behaviour occurs among the araneophagous Salticidae, and it varies greatly in method. Many of the spider-hunting species quite commonly will attack other spiders, whether fellow salticids or not, in the same way as any other prey, but some kinds resort to web invasion; nonspecialists such as Phidippus audax sometimes attack prey ensnared in webs, basically in acts of kleptoparasitism — sometimes they leap onto and eat the web occupant itself, or simply walk over the web for that purpose.

Salticidae in the genera Brettus, Cyrba, Gelotia, and Portia display more advanced web-invasion behavior. They slowly advance onto the web and vibrate the silk with their pedipalps and legs. In this respect, their behaviour resembles that of the Mimetidae, probably the most specialised of the araneophagous spider families. If the web occupant approaches in the manner appropriate to dealing with ensnared prey, the predator attacks.[24]

The foregoing examples present the Salticidae as textbook examples of active hunters; they would hardly seem likely to build webs other than those used in reproductive activities, and in fact, most species really do not build webs to catch prey. However, exceptions occur, though even those that do build capture webs generally also go hunting like other salticids. Some Portia species, for example, spin capture webs that are functional, though not as impressive as some orb webs of the Araneidae; Portia webs are of an unusual funnel shape and apparently adapted to the capture of other spiders. Spartaeus species, on the other hand, largely capture moths in their webs. In their review of the ethology of Salticidae, Richman and Jackson speculate on whether such web building is a relic of the evolution of this family from web-building ancestors.[24]

In hunting, Salticidae also use their silk for a tether to enable them to reach prey that otherwise would be inaccessible. For example, by advancing towards the prey to less than the jumping distance, then retreating and leaping in an arc at the end of the tether line, many species can leap onto prey on vertical or even on inverted surfaces, which of course in a gravitational field would not be possible without such a tether.

Having made contact with the prey, hunting Salticidae administer a bite to inject rapidly acting venom that gives the victim little time to react.[25] In this respect, they resemble the Mimetidae and Thomisidae, families that ambush prey that often are larger than the predator, and they do so without securing the victim with silk; they accordingly must immobilise it immediately and their venom is adapted accordingly.

Source: Wiki

Spider - Argiope


The genus Argiope includes rather large and spectacular spiders that often have a strikingly coloured abdomen. These spiders are distributed throughout the world. Most countries in tropical or temperate climates host one or more species that are similar in appearance. The etymology of the name is from a Greek name meaning "silver-faced."

Common names

Writing spider in South Carolina
In North America, Argiope aurantia is commonly known as the black and yellow garden spider, zipper spider, corn spider, and writing spider, because of the similarity of the web stabilimenta to writing.

In England, Argiope bruennichi, where it is found only on the southern coast, and in other parts of Europe, including Germany, is also known as the wasp spider. In Australia, Argiope keyserlingi and A. aetherea are known as St. Andrew's Cross spiders, for their habit of resting in the web with legs outstretched in the shape of an X, the cross of St. Andrew. The large white zigzag in the centre of its web is called the stabilimentum or web decoration.

The East Asian species Argiope amoena is known in Japan as kogane-gumo. In the Philippines, they are known as gagambang ekis ("X spider", again due to the stabilementa), and gagambang pari ("priest spider", due to the spider's body resembling a priest's head with a mitre).

Web

The average orb web is practically invisible, and it is easy to blunder into one and end up covered with a sticky web. The very easily visible pattern of banded silk made by Argiope is pure white, and some species make an "X" form, or a zigzag type of web (often with a hollow centre). The spider then aligns one pair of its legs with each of the four lines in the hollow "X", making a complete "X" of white lines with a very eye-catching spider coloured bright yellow on a field of black or variegated red white and yellow stripes forming its centre.


The white patterns are called stabilimentum and reflect UV light. They have been shown to play a role in attracting prey to the web, and possibly to prevent its destruction by large animals. The centres of their large webs are often just under 1 metre above the ground, so they are too low for anything much larger than a rabbit to walk under.

The overtness of the spider and its web thus has been speculated to prevent larger creatures from accidentally destroying the web and possibly crushing the spider underfoot.

Other studies suggest that the stabilimenta may actually lead predators to the spider; species such as A. keyserlingi place their web predominantly in closed, complex habitats such as among sedges.

As Argiope sit in the centre of their web during the day, they have developed several responses to predators, such as dropping off the web, retreating to the periphery of the web, or even rapidly pumping the web in bursts of up to 30 seconds, similar to the motion done by the unrelated Pholcus phalangioides

Reproduction
The male spider is much smaller than the female, and unassumingly marked. When it is time to mate, he spins a companion web alongside the female's. After mating, the female lays her eggs, placing her egg sac into the web. The sac contains between 400 and 1400 eggs.

These eggs hatch in autumn, but the spiderlings overwinter in the sac and emerge during the spring. The egg sac is composed of multiple layers of silk and protects its contents from damage; however, many species of insects have been observed to parasitise the egg sacs.

Bite

Like almost all other spiders, Argiope are harmless to humans. As is the case with most garden spiders, they eat insects, and they are capable of consuming prey up to twice their size. A. savigny was even reported to occasionally feed on the small bat Rhynchonycteris naso.[3]


They might bite if grabbed, but other than for defense they do not attack large animals. Their venom is not regarded as a serious medical problem for humans; it often contains a library of polyamine toxins with potential as therapeutic medicinal agents.[4] Notable among these is the argiotoxin ArgTX-636 (A. lobata).

A bite by the black and yellow garden spider (Argiope aurantia) is comparable to a bee sting with redness and swelling. For a healthy adult, a bite is not considered an issue.

Though they are not aggressive spiders, the very young, elderly, or those with compromised immune systems should exercise caution just as one would around a beehive.


Source: Wiki

Trachelas Tranquillus


Spiders (order Araneae) are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms.[2] Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exceptions of air and sea colonization. As of November 2015, at least 45,700 spider species,[3] and 114 families have been recorded by taxonomists.[1] However, there has been dissension within the scientific community as to how all these families should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900.[4]

Anatomically, spiders differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax and abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae. In all except the most primitive group, the Mesothelae, spiders have the most centralized nervous systems of all arthropods, as all their ganglia are fused into one mass in the cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure.

Their abdomens bear appendages that have been modified into spinnerets that extrude silk from up to six types of glands. Spider webs vary widely in size, shape and the amount of sticky thread used. It now appears that the spiral orb web may be one of the earliest forms, and spiders that produce tangled cobwebs are more abundant and diverse than orb-web spiders. Spider-like arachnids with silk-producing spigots appeared in the Devonian period about 386 million years ago, but these animals apparently lacked spinnerets. True spiders have been found in Carboniferous rocks from 318 to 299 million years ago, and are very similar to the most primitive surviving suborder, the Mesothelae. The main groups of modern spiders, Mygalomorphae and Araneomorphae, first appeared in the Triassic period, before 200 million years ago.


A herbivorous species, Bagheera kiplingi, was described in 2008,[5] but all other known species are predators, mostly preying on insects and on other spiders, although a few large species also take birds and lizards. Spiders use a wide range of strategies to capture prey: trapping it in sticky webs, lassoing it with sticky bolas, mimicking the prey to avoid detection, or running it down. Most detect prey mainly by sensing vibrations, but the active hunters have acute vision, and hunters of the genus Portia show signs of intelligence in their choice of tactics and ability to develop new ones. Spiders' guts are too narrow to take solids, and they liquefy their food by flooding it with digestive enzymes and grinding it with the bases of their pedipalps, as they do not have true jaws.


Male spiders identify themselves by a variety of complex courtship rituals to avoid being eaten by the females. Males of most species survive a few matings, limited mainly by their short life spans. Females weave silk egg-cases, each of which may contain hundreds of eggs. Females of many species care for their young, for example by carrying them around or by sharing food with them. A minority of species are social, building communal webs that may house anywhere from a few to 50,000 individuals. Social behavior ranges from precarious toleration, as in the widow spiders, to co-operative hunting and food-sharing. Although most spiders live for at most two years, tarantulas and other mygalomorph spiders can live up to 25 years in captivity.

While the venom of a few species is dangerous to humans, scientists are now researching the use of spider venom in medicine and as non-polluting pesticides. Spider silk provides a combination of lightness, strength and elasticity that is superior to that of synthetic materials, and spider silk genes have been inserted into mammals and plants to see if these can be used as silk factories. As a result of their wide range of behaviors, spiders have become common symbols in art and mythology symbolizing various combinations of patience, cruelty and creative powers. An abnormal fear of spiders is called arachnophobia.


Body plan

Spiders are chelicerates and therefore arthropods.[6] As arthropods they have: segmented bodies with jointed limbs, all covered in a cuticle made of chitin and proteins; heads that are composed of several segments that fuse during the development of the embryo.[7] Being chelicerates, their bodies consist of two tagmata, sets of segments that serve similar functions: the foremost one, called the cephalothorax or prosoma, is a complete fusion of the segments that in an insect would form two separate tagmata, the head and thorax; the rear tagma is called the abdomen or opisthosoma.[6] In spiders, the cephalothorax and abdomen are connected by a small cylindrical section, the pedicel.[8] The pattern of segment fusion that forms chelicerates' heads is unique among arthropods, and what would normally be the first head segment disappears at an early stage of development, so that chelicerates lack the antennae typical of most arthropods. In fact, chelicerates' only appendages ahead of the mouth are a pair of chelicerae, and they lack anything that would function directly as "jaws".[7][9] The first appendages behind the mouth are called pedipalps, and serve different functions within different groups of chelicerates.[6]


Spiders and scorpions are members of one chelicerate group, the arachnids.[9] Scorpions' chelicerae have three sections and are used in feeding.[10] Spiders' chelicerae have two sections and terminate in fangs that are generally venomous, and fold away behind the upper sections while not in use. The upper sections generally have thick "beards" that filter solid lumps out of their food, as spiders can take only liquid food.[8] Scorpions' pedipalps generally form large claws for capturing prey,[10] while those of spiders are fairly small appendages whose bases also act as an extension of the mouth; in addition, those of male spiders have enlarged last sections used for sperm transfer.[8]

In spiders, the cephalothorax and abdomen are joined by a small, cylindrical pedicel, which enables the abdomen to move independently when producing silk. The upper surface of the cephalothorax is covered by a single, convex carapace, while the underside is covered by two rather flat plates. The abdomen is soft and egg-shaped. It shows no sign of segmentation, except that the primitive Mesothelae, whose living members are the Liphistiidae, have segmented plates on the upper surface.[8]

House Gecko - Hemidactylus frenatus

The common house gecko (Hemidactylus frenatus) (not to be confused with the Mediterranean species Hemidactylus turcicus known as Mediterranean house gecko), is a native of Southeast Asia. It is also known as the Pacific house gecko, the Asian house gecko, house lizard, or Moon Lizard.[2] Most geckos are nocturnal, hiding during the day and foraging for insects at night. They can be seen climbing walls of houses and other buildings in search of insects attracted to porch lights, hence their name "house gecko". Spread around the world by ships, these geckos are now common in the Deep South of the United States, large parts of tropical and sub-tropical Australia, and many other countries in South and Central America, Africa, South Asia, and the Middle East. They grow to a length of between 75–150 mm (3–6 in), and live for about 5 years. These small geckos are non-venomous and harmless to humans. Medium to large geckos may bite if distressed, however their bite is gentle and will not pierce skin.

A tropical gecko, Hemidactylus frenatus thrives in warm, humid areas where it can crawl around on rotting wood in search of the insects it eats. The animal is very adaptable and may prey on insects and spiders, displacing other reptiles.

Like many geckos, this species can lose its tail when alarmed. Its call or chirp rather resembles the sound "gecko, gecko". However, this is an interpretation, and the sound may also be described as "tchak tchak tchak" (often sounded three times in sequence). In Asia/Southeast Asia, notably Indonesia, Thailand, Singapore, and Malaysia, geckos have local names onomatopoetically derived from the sounds they make: Hemidactylus frenatus is called "chee chak" or "chi chak" (pr- chee chuck), said quickly. Also commonly spelled as "cicak" in Malay dictionaries. In the Philippines they are called "butiki" in Tagalog, or "tiki" in Visayan, and in Thailand "jing-jok" (Thai: จิ้งจก[3]). In some parts of India and in Pakistan they are called "chhipkali" (Urdu:چہپکلی, Hindi: छिपकली), from chhipkana, to stick. In Nepal they are called "bhitti" (Nepali: भित्ती) or "mausuli" (Nepali: माउसुली). In other parts of India they are called "jhiti piti" (Oriya: ଝିଟିପିଟି), "paal" (Marathi: पाल), "gawli" or "palli" (Malayalam: ഗവ്ളി (gawli), പല്ലി (palli), Tamil: பல்லி (palli)), Kannada: ಹಲ್ಲಿ (halli). In West Bengal and Bangladesh they are called "tiktiki" (Bengali: টিকটিকি) as the sound is perceived as "tik tik tik". In Sri Lanka they are called "huna" in singular form (Sinhalese: හුනා). In Central America they are sometimes called "Limpia Casas" (Spanish: Housecleaners) because they reduce the amount of insects and other arthropods in homes

House geckos in captivity
House geckos can be kept as pets in a vivarium with a clean substrate, and typically require a heat source and a place to hide in order to regulate their body temperature, and a system of humidifiers and plants to provide them with moisture.

The species will cling to vertical or even inverted surfaces when at rest. In a terrarium they will mostly be at rest on the sides or on the top cover rather than placing themselves on plants, decorations or on the substrate, thus being rather inconspicuous.

House geckos are also used as a food source for some snakes.

Invasive species
In many countries, Hemidactylus frenatus is an introduced species that is considered a pest[4] and even a "serious threat species" to local wildlife.[5] While the impact of the Asian house gecko has not yet been closely studied, there is evidence that this "generalist predator"[6] can compete with native gecko species for resources and perhaps replace them, especially in urban areas.[5][7] Asian house geckos have transferred disease-carrying mites to native species.[8]

Superstition

Two wall sculptures of geckos on the wall of the Mandapam of the Siva temple inside Vellore Fort, Tamil Nadu, India (2012)
Geckos are considered poisonous in many parts of the world. In Southeast Asia, geckos are believed to be carriers of good omen.[citation needed]

In Yemen and other Arab countries, it is believed that skin diseases result from geckos running over the face of someone who is asleep.

An elaborate system of predicting good and bad omens based on the sounds made by geckos, their movement and the rare instances when geckos fall from roofs has evolved over centuries in India.[9][10] In some parts of India, the sound made by geckos is considered a bad omen; while in Bangladesh and Nepal, it is considered to be an endorsement of the truthfulness of a statement made just before, because the sound "tik tik tik" coincides with "thik thik thik" (Bengali:ঠিক ঠিক ঠিক) (Nepali:ठिक ठिक ठिक), which in Bengali and Nepali means "right right right", i.e., a three-fold confirmation. The cry of a gecko from an east wall as one is about to embark on a journey is considered auspicious, but a cry from any other wall is supposed to be inauspicious. A gecko falling on someone's right shoulder is considered good omen, but a bad omen if it drops on the left shoulder. In Punjab, it is believed that contact with the urine of a gecko will cause leprosy.[11] In some places in India, it is believed that watching a lizard on the eve of Dhanteras is a good omen or a sign of prosperity.

Cat - Felis catus



The domestic cat[1][5] (Latin: Felis catus) or the feral cat[5][3] (Latin: Felis silvestris catus) is a small, typically furry, carnivorous mammal. They are often called house cats when kept as indoor pets or simply cats when there is no need to distinguish them from other felids and felines.[6] Cats are often valued by humans for companionship and for their ability to hunt vermin. There are more than 70 cat breeds; different associations proclaim different numbers according to their standards.

Cats are similar in anatomy to the other felids, with a strong, flexible body, quick reflexes, sharp retractable claws, and teeth adapted to killing small prey. Cat senses fit a crepuscular and predatory ecological niche. Cats can hear sounds too faint or too high in frequency for human ears, such as those made by mice and other small animals. They can see in near darkness. Like most other mammals, cats have poorer color vision and a better sense of smell than humans. Cats, despite being solitary hunters, are a social species and cat communication includes the use of a variety of vocalizations (mewing, purring, trilling, hissing, growling, and grunting), as well as cat pheromones and types of cat-specific body language.[7]

Cats have a high breeding rate. Under controlled breeding, they can be bred and shown as registered pedigree pets, a hobby known as cat fancy. Failure to control the breeding of pet cats by neutering and the abandonment of former household pets has resulted in large numbers of feral cats worldwide, requiring population control.[8] This has contributed, along with habitat destruction and other factors, to the extinction of many bird species. Cats have been known to extirpate a bird species within specific regions and may have contributed to the extinction of isolated island populations.[9] Cats are thought to be primarily, though not solely, responsible for the extinction of 33 species of birds, and the presence of feral and free ranging cats makes some locations unsuitable for attempted species reintroduction in otherwise suitable locations.[10]

Since cats were venerated in ancient Egypt, they were commonly believed to have been domesticated there,[11] but there may have been instances of domestication as early as the Neolithic from around 9,500 years ago (7,500 BC).[12] A genetic study in 2007 concluded that domestic cats are descended from Near Eastern wildcats, having diverged around 8,000 BC in West Asia.[11][13] A 2016 study found that leopard cats were undergoing domestication independently in China around 5,500 BC, though this line of partially domesticated cats leaves no trace in the domesticated populations of today.[14][15]

As of a 2007 study, cats are the second most popular pet in the United States by number of pets owned, behind the first, which is freshwater fish.[16]

Senses
Reflection of camera flash from the tapetum lucidum
Cats have excellent night vision and can see at only one-sixth the light level required for human vision.[53]:43 This is partly the result of cat eyes having a tapetum lucidum, which reflects any light that passes through the retina back into the eye, thereby increasing the eye's sensitivity to dim light.[75] Another adaptation to dim light is the large pupils of cats' eyes. Unlike some big cats, such as tigers, domestic cats have slit pupils.[76] These slit pupils can focus bright light without chromatic aberration, and are needed since the domestic cat's pupils are much larger, relative to their eyes, than the pupils of the big cats.[76] At low light levels a cat's pupils will expand to cover most of the exposed surface of its eyes.[77] However, domestic cats have rather poor color vision and (like most nonprimate mammals) have only two types of cones, optimized for sensitivity to blue and yellowish green; they have limited ability to distinguish between red and green.[78] A 1993 paper reported a response to middle wavelengths from a system other than the rods which might be due to a third type of cone. However, this appears to be an adaptation to low light levels rather than representing true trichromatic vision.[79]

Cats have excellent hearing and can detect an extremely broad range of frequencies. They can hear higher-pitched sounds than either dogs or humans, detecting frequencies from 55 Hz to 79,000 Hz, a range of 10.5 octaves, while humans and dogs both have ranges of about 9 octaves.[80][81] Cats can hear ultrasound, which is important in hunting[82] because many species of rodents make ultrasonic calls.[83] However, they do not communicate using ultrasound like rodents do. Cats' hearing is also sensitive and among the best of any mammal,[80] being most acute in the range of 500 Hz to 32 kHz.[84] This sensitivity is further enhanced by the cat's large movable outer ears (their pinnae), which both amplify sounds and help detect the direction of a noise.[82]


Cats' whiskers are highly sensitive to touch.
Cats have an acute sense of smell, due in part to their well-developed olfactory bulb and a large surface of olfactory mucosa, about 5.8 cm2 (0.90 in2) in area, which is about twice that of humans.[85] Cats are sensitive to pheromones such as 3-mercapto-3-methylbutan-1-ol,[86] which they use to communicate through urine spraying and marking with scent glands.[87] Many cats also respond strongly to plants that contain nepetalactone, especially catnip, as they can detect that substance at less than one part per billion.[88] About 70—80% of cats are affected by nepetalactone.[89] This response is also produced by other plants, such as silver vine (Actinidia polygama) and the herb valerian; it may be caused by the smell of these plants mimicking a pheromone and stimulating cats' social or sexual behaviors.[90]

Cats have relatively few taste buds compared to humans (470 or so versus more than 9,000 on the human tongue).[91] Domestic and wild cats share a gene mutation that keeps their sweet taste buds from binding to sugary molecules, leaving them with no ability to taste sweetness.[92] Their taste buds instead respond to amino acids, bitter tastes, and acids.[93] Cats and many other animals have a Jacobson's organ located in their mouths that allows them to taste-smell certain aromas in a way which humans have no experience of. Cats also have a distinct temperature preference for their food, preferring food with a temperature around 100 °F (38 °C) which is similar to that of a fresh kill and routinely rejecting food presented cold or refrigerated (which would signal to the cat that the "prey" item is long dead and therefore possibly toxic or decomposing).[91]

To aid with navigation and sensation, cats have dozens of movable whiskers (vibrissae) over their body, especially their faces. These provide information on the width of gaps and on the location of objects in the dark, both by touching objects directly and by sensing air currents; they also trigger protective blink reflexes to protect the eyes from damage.[53]:47

Most breeds of cat have a noted fondness for settling in high places, or perching. In the wild, a higher place may serve as a concealed site from which to hunt; domestic cats may strike prey by pouncing from a perch such as a tree branch, as does a leopard.[94] Another possible explanation is that height gives the cat a better observation point, allowing it to survey its territory. During a fall from a high place, a cat can reflexively twist its body and right itself using its acute sense of balance and flexibility.[95] This is known as the cat righting reflex. An individual cat always rights itself in the same way, provided it has the time to do so, during a fall. The height required for this to occur is around 90 cm (3.0 ft). Cats without a tail (e.g. Manx cats) also have this ability, since a cat mostly moves its hind legs and relies on conservation of angular momentum to set up for landing, and the tail is little used for this feat.[96]

Source: Wiki


Marigold - Tagetes



Tagetes is a genus of annual or perennial, mostly herbaceous plants in the sunflower family (Asteraceae or Compositae). It was described as a genus by Linnaeus in 1753.

The genus is native to North and South America, but some species have become naturalized around the world. One species, T. minuta, is considered a noxious invasive plant in some areas

Description
Tagetes species vary in size from 0.1 to 2.2 m tall. Most species have pinnate green leaves. Blooms naturally occur in golden, orange, yellow, and white colors, often with maroon highlights. Floral heads are typically (1-) to 4–6 cm diameter, generally with both ray florets and disc florets. In horticulture, they tend to be planted as annuals, although the perennial species are gaining popularity.

Depending on the species, Tagetes species grow well in almost any sort of soil. Most horticultural selections grow best in soil with good drainage, even though some cultivars are known to have good tolerance to drought.

Nomenclature
The name Tagetes is from the name of the Etruscan Tages.

The common name in English, "marigold", is derived from "Mary's gold", a name first applied to a similar plant native to Europe, Calendula officinalis. See marigold for other plants commonly called marigold. In Nepal, it is called 'शयपत्री' that means hundred-leafed flower, referring to its many florets per head.

The most commonly cultivated varieties of Tagetes are known variously as African marigolds (usually referring to cultivars and hybrids of Tagetes erecta, although this species is not native to Africa), or French marigolds (usually referring to hybrids and cultivars of Tagetes patula, many of which were developed in France, although the species is not native to that country). The so-called signet marigolds are hybrids derived mostly from Tagetes tenuifolia.

Tagetes minuta is the source of commercial "tagetes oil" used in industry. It is now a naturalized species in Africa, Hawaii, and Australia, and is considered an invasive species (weed) in some regions.

Cultivation and uses

Marigolds decorating a grave for Day of the Dead in Mexico
Depending on the species, marigold foliage has a musky, pungent scent, though some varieties have been bred to be scentless. It is said to deter some common insect pests, as well as nematodes. Tagetes species are hence often used in companion planting for tomato, eggplant, chili pepper, tobacco, and potato. Due to antibacterial thiophenes exuded by the roots, Tagetes should not be planted near any legume crop.[8] Some of the perennial species are deer-, rabbit-, rodent- and javalina or peccary-resistant.[8]

T. minuta (khakibush or huacatay), originally from South America, has been used as a source of essential oil for the perfume and industry known as tagette or "marigold oil", and as a flavourant in the food and tobacco industries. It is commonly cultivated in South Africa, where the species is also a useful pioneer plant in the reclamation of disturbed land.

The florets of Tagetes erecta are rich in the orange-yellow carotenoid lutein and are used as a food colour (INS-number E161b) in the European Union for foods such as pasta, vegetable oil, margarine, mayonnaise, salad dressing, baked goods, confectionery, dairy products, ice cream, yogurt, citrus juice and mustard. In the United States, however, the powders and extracts are only approved as colorants in poultry feed.

Marigolds are recorded as a food plant for some Lepidoptera caterpillars including the dot moth, and a nectar source for other butterflies. They are often part of butterfly gardening plantings. In the wild, many species are pollinated by beetles.[8]

Cultural significance

Marigold varieties prepared as offerings to a god during the Hindu festival of Maha Shivaratri
Tagetes lucida[edit]
The species Tagetes lucida, known as pericón, is used to prepare a sweetish, anise-flavored medicinal tea in Mexico. It is also used as a culinary herb in many warm climates, as a substitute for tarragon, and offered in the nursery as "Texas tarragon" or "Mexican mint marigold".


Tagetes minuta
Tagetes minuta, native to southern South America, is a tall, upright marigold plant with small flowers used as a culinary herb in Peru, Ecuador, and parts of Chile and Bolivia, where it is called by the Incan term huacatay. The paste is used to make the popular potato dish called ocopa. Having both "green" and "yellow/orange" notes, the taste and odor of fresh T. minuta is like a mixture of sweet basil, tarragon, mint and citrus. It is also used as a medicinal tea in some areas.[9]

Tagetes - various species

Marigold on an altar in Mexico
The marigold is very significant in Nepalese culture, where marigold garlands are used almost in every household, especially during the Tihar festival. It is always sold in the markets for daily worships and rituals.

The marigold was regarded as the flower of the dead in pre-Hispanic Mexico, parallel to the lily in Europe, and is still widely used in the Day of the Dead celebrations. The marigold is also widely cultivated in India and Thailand, particularly the species T. erecta, T. patula, and T. tenuifolia. Vast quantities of marigolds are used in garlands and decoration for weddings, festivals, and religious events. Marigold cultivation is extensively seen in Andhra Pradesh, Tamil Nadu, West Bengal, Karnataka, and Uttar Pradesh[10] states of India.

In Ukraine, chornobryvtsi (T. erecta, T. patula, and the signet marigold, l. tenuifolia) are regarded as one of the national symbols, and are often mentioned in songs, poems, and tales.