Senin, 25 Juni 2012


The Biggest Animals Kingdom | Platypus | The body and the broad, flat tail of the platypus are equipped with thick fur and brown covers to keep the traps of an insulating layer of air, the animal warm. The coat is waterproof, and the texture is similar to that of a platypus with its tail mole.The storage of fat reserves (an adaptation in animals like the Tasmanian Devil, and fat-tailed sheep found). The strap is greater on the front and back legs when walking on the ground, unlike bird's beak (in which separate the top and bottom to reveal the mouth), the snout of the Platypus is a sensory organ, the mouth of the folded bottom. Weight varies considerably, from 0.7 to 2.4 kg (1.5 to 5.3 lb), larger in males than in females: males average 50 cm (20 inches) total length while females average 43 cm (17 inches). The platypus has an average body temperature of about 32 ° C (90 ° F) instead of 37 ° C (99 ° F), typical of placental mammals. Research suggests that it was a gradual adaptation to harsh environmental conditions from the few surviving species of monotremes, rather than a historical characteristic of monotremes.

Modern Platypus young have three-pointed molars which they lose before or shortly after leaving the breeding burrow; have Adults keratinized massive blocks in their place. Platypus jaw is constructed differently from those of other mammals, and the muscle of the jaw opening is different. The platypus has extra bones in the shoulder girdle, including an interclavicle, which is not found in other mammals. The office of the platypus electric front is the most sensitive of all monotremes. Receptors in the electric lines in the skin of the rostrocaudal arranged ticket, while mechanoreceptors (tactile sensing) are evenly distributed over the bill. Both electroreceptors and mechanoreceptors in the bill dominate the somatotopic map of the platypus brain, in the same way human hands dominate the Penfield homunculus map.The Platypus can determine the direction of an electric source, perhaps by comparing differences in signal strength on the sheet of electroreceptors. 

The convergence of inputs and tactile cortical electrosensory that a mechanism for determining the distance of prey to move when encountered two electrical signals and mechanical pressure pulses, the difference between arrival times of the calculation into two signals is capable of enabling the distance. The platypus feeds either by sight or smell, and closed his eyes, ears, nose, and each time he dives. Experiments have shown that the Platypus will even react to an "artificial shrimp" if a small electrical current is passed through. The platypus is semi-aquatic, living in small streams and rivers on a wide range of highlands of Tasmania and the Australian Alps to the rainforests of coastal Queensland as far north as the base of Cape York Peninsula.

 In captivity, platypuses have lived up to 17 years, and wild specimens that were recovered while 11 years. Natural enemies are snakes, water rats, lizards, hawks, owls and eagles. Low Platypus numbers in northern Australia are possibly due to the looting by crocodiles.  The platypus is an excellent swimmer and spends much time in the water in search of food. When swimming, it can be distinguished from other Australian mammals by the absence of visible ears. Unique among mammals, hanging out with a swim in a rowing motion alternating the two front feet, although all four feet webbed feet platypus supporting the hind legs (which is held against the body), not to advance, but are used for steering in combination with the tail.

The species is endothermic, maintaining their body temperature at 32 ° C (90 ° F), lower than most mammals, even when foraging for hours in water below 5 ° C (41 ° F). The platypus is a carnivore: it feeds on annelid worms and insects, freshwater shrimp, larvae and Yabbies (freshwater crayfish) that it digs on the riverbed with its snout or catches while swimming. The platypus needs to eat about 20% of their weight every day, he is averaging 12 hours per day expenditures for food needs. When he is not in the water, the platypus a short, straight off the construction of an oval cross-section in retirement, almost always in the bank, not far from the water level, and often hidden under a protective tangle of roots.

When the platypus was first encountered by European naturalists, they were about whether the female laid eggs divided. Recognizing the high cost of wiring England by word, Caldwell famous, but tersely wired London, "laying monotremes, the egg meroblastic." In other words, lay eggs, monotremes, and eggs are similar to those of reptiles in the only part of the egg cell divides, how it develops. The species is a breeding season, mating occurs between June and October, although some local variation occurs between populations over its frequency range. Historical observation, mark-recapture studies and preliminary investigations of population genetics indicate the possibility of both resident and members of the population, and suggest a polygynous system.

Outside the breeding season of the platypus lives buried in a single floor, the entrance is about 30 cm (12 inches) above the water table. The female platypus has a pair of ovaries but only the left is functional It sets 1-3 (usually two) small leathery eggs (similar to those of reptiles), about 11 mm (0.43 in.) in diameter and slightly rounder than bird eggs. The yolk is absorbed by the developing young. During the second phase, the numbers and development, in the final stages, the egg tooth. The newly hatched young are vulnerable, blind, hairless, and are fed by breast milk. Although the mammary glands, the Platypus lacks teats. During incubation and weaning, the mother leaves the den for short periods at first, to seek food.



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