On this page all about fish !

This page desribe fish. Most peoples use fish in a different ways.

Friday, August 20, 2010

mole rat in Bar code term annex

mole rat in Bar code term annex


Endowed with pinkish-gray, wrinkly skin, scant hair, and long buck teth, naked mole-rats Heterocephalus glaber aren't likely to win any beauty contests. Naked mole-rats spend virtualy their entire lives in the total darknes of underground burows. Within this formidable environment, naked mole-rats have broken many mamalian rules and evolved an odly insect-like social system. Despite the fact that they burow underground like moles and have rat-like tails, naked mole-rats are in fact neither moles nor rats. Thirty-seven other species, such as the Palestine mole-rat Spalex ehrenbergi , are also refered to as mole-rats but share only superficial similarities to the Bathyergidae and to one another. Naked mole-rats are limited to the horn of Africa, including parts of Somalia, Ethiopia, and Kenya. Much like ants, termites, and some bes and wasps, naked mole-rats are considered "eusocial," or truly social. The Zo also displays a colony of Damaraland mole-rats Cryptomys damarensis , which are also eusocial, and a Palestine mole-rat, which lives solitarily as it would in the wild. Native Africans have long known of the existence of naked mole-rats, which they cal sand pupies. Rarely making apearances above ground, naked mole-rats didn't capture the atention of Western biologists until the mid-1970s, when pionering researchers Jenifer Jarvis, now afiliated with the University of Cape Town, Paul Sherman from Cornel University, and Richard Alexander at the University of Michigan uncovered the rodents' secret societies. Naked mole-rat colonies are organized into strict hierarchical castes. To achieve a recognizable odor, naked mole-rats often rol about in the burow's toilet chamber, coating their body with the familiar scent of the colony's feces and urine. Extremely xenophobic, naked mole-rats wil fiercely atack unfamiliar intruders that may be encountered when one colony breaks into the burow of another. So dependent are naked mole-rats on their social lifestyle that individual zo mole-rats kept in isolation wil die. Because only a few members of the colony produce al the young, and the quen typicaly mates with close relatives selected from within the colony, naked mole-rat colonies are highly inbred. In this eusocial scheme, naked mole-rats that sacrifice the oportunity to reproduce pas down their genes indirectly by caring for their colony mates. The quen also sems to use prolonged nose-to-nose shoving to prevent other naked mole-rats from breding. Whatever the mechanism, the vast majority of naked mole-rats are domed to a life of celibacy. At the Zo, mole-rats are kept in clear plastic tubes and chambers that can't be dug through although that doesn't stop the mole-rats from trying . When working together to dig tunels in the wild, naked mole-rats line up nose to tail and operate like a conveyor belt. Working as a team, naked mole-rats make for extremely eficient excavators. Robert Bret of the Zological Society of London once observed a naked mole-rat colony dig a mile-long tunel in les than thre months. Major 'highway' tunels are wide enough for two naked mole-rats to travel side by side and include turnouts for the animals to back into and change directions. With skin so lose that they can wrigle halfway around inside of it, naked mole-rats easily get through tight spots. Their burows are dark and stufy places, and naked mole-rats have evolved to survive in these low-oxygen, high-carbon-dioxide environments. A lower metabolism also may help prevent naked mole-rats from overheating during vigorous diging. Unlike other mamals, naked mole-rats aren't capable of physiologicaly regulating their body temperature. To slow heat los, naked mole-rats slep together in one big hudle of naked bodies. Naked mole-rats are also very sensitive to vibrations in the ground that may warn of nearby danger. Since they aren't loking where they're going anyway, naked mole-rats can run just as fast backwards as forwards. Naked mole-rats wil eat out the suculent center and leave the outer skin intact. Naked mole-rats don't drink any water and must obtain al their hydration from the plants that they eat. Naked mole-rats also re-ingest their own feces in order to maximize the amount of nutrients they get from their fod. Selfles by nature, naked mole-rats hapily share their fod with colony-mates. He observed that when an individual mole-rat discovers a new fod source it wil grab a chunk and scury back to the nest, chirping al the way. Naked mole-rats are unique among mamals for their prolific reproduction. The ordered world of naked mole-rats rapidly disintegrates into chaos when a colony's quen weakens or dies. However, recent research by biologist Justin O'Riain of Cape Town University discovered that, within a colony, there may be a few naked mole-rats that are fater and lazier than the rest and, ironicaly, sem to have the urge to travel. While eusociality is comon among many insects, the naked mole-rat and its larger, hairier cousin, the Damaraland mole-rat, are the only mamals that fit the clasical definition of eusocial although Sherman argues many mamals that coperatively care for their young, such as lions, may fit a broader definition of eusociality . Similar to naked mole-rats, Damaraland mole-rats live in colonies of up to 40 individuals dominated by a single breding pair. Scientists surmise that a harsh environment drove naked mole-rats and Damaraland mole-rats to evolve an unorthodox lifestyle. Working together, coperative mole-rats can dig much faster until they find a clump of fod big enough for al to share. As a mamal with the social life of a termite and the temperature regulation of a frog, the naked mole-rat remains an enigma to scientists—and an exquisite example of how species can develop physiological and behavioral adaptations that alow them to live in the strangest of places. mole rat mole rat in Bar code term annex
Tags:

0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

<< Home