Wednesday, October 29, 2008

Ratitae

What do you think, when I mention the word "birds"?
We immediately think of their power of flight, we think of the free spirited birds, who just-like-that spread out their wings and take off.... I still remember what my friend told me when I refused to buy a scooty in view of fuel conservation and pollution; she said ' It’s like having a pair of wings and flying to any destination without much ado'. Yes, we all have this fascination for flying, to have a bird’s eye view of the place we live in, the sense of freedom it brings, the list is never ending (yes yes i bought a scooty 8 years ago : ) But do we know of birds that can’t fly!!! It is a fact that a set of birds can’t fly, their basic distinction from the rest of the animals is not there. If you think of the hen and duck, you’re wrong. The Hen and Duck are not one of them as they are capable of short distance flight.
Ratitae - terrestrial birds without keel (the bone which supports the flight muscles) to the sternum, absolutely flightless.
Any bird species that cannot fly because its smooth, or raft-like, sternum (breastbone) lacks a keel to which flight muscles can be anchored. The group includes some of the largest birds of all time. The ratites include the Afro-Asian Ostrich, common name for a large flightless bird of Africa and their South American counterparts the Rhea as well as a number of orders now or recently native to Australia, New Zealand, and New Guinea—the Emu and the Cassowary, the kiwi; the extinct Moa; the Madagascan elephant birds and several other extinct orders.
The flightless penguins are not ratites, since they have neither bony palate nor flat breastbone. In addition, their wings are powerful swim fins, and their chest muscles and sternum are as developed as those of any flying bird. The orders of ratites are classified in the Phylum: Chordata, Subphylum: Vertebrata, Class: Aves, Order: Ratitae
By the way for those bird watchers and naturalists... the months of November to March are a season in which you can see different kinds of migratory birds in the Vedanthangal Bird Sanctuary near Chennai. You can see birds from as far as Siberia, Artic and North America. It is a visual treat. Enjoy!





Wednesday, July 2, 2008

Hermit Crab


We all have heard of the great sadhus and wise of the old. These Hermits are supposed to have meditated in a particular stance mostly a yogic position for even years! anthills were built around them but nothing deterred these people from stopping their meditation. They made them as their home.

Today's class is a
lso about one such crab. Its called the hermit crab.



Hermit crabs are crustaceans, not closely related to true crabs. As the normal ones have four pairs of walking legs while these have only three pairs along with having a long soft abdomen which is protected from predators by the adaptation of carrying around a salvaged empty seashell, into which the whole crab's body can retract. Most frequently hermit crabs utilize the shells of sea snails, marine gastropod molluscs. The tip of the hermit crab's abdomen is adapted to clasp strongly onto the columella of the snail shell. As the hermit crab grows in size it has to find a larger shell and abandon the previous one.

This habit of living in a second hand shell is what gave rise to the popular name "hermit crab", which is a reference to the idea of a hermit living alone in a small cave. Hermit crabs live in the wild in colonies of 100 or more, and do not thrive in smaller numbers.

The availability of empty snail shells at any given place depends primarily on the relative abundance of gastropods in the right range of sizes, compared to the demographics of the population of hermit crabs. An equally important issue is the frequency of organisms which prey upon gastropods but leave the shells intact. They are also very famous for their mutualism with sea anemone

There is also a video caught by me in the Andamans. Watch.

video

Wednesday, June 25, 2008

Jesus Bug

Have you heard of Jesus Bug? Its very common in our ponds, temple tanks and wells… now you understand who they are? Water striders—those six-legged insects that float and glide across the surface of ponds, streams, and lakes—are sometimes called Jesus bugs or pond skaters, Gerris remigis are considered the most advanced surface-dwelling water bug found in nature. How they are able to do it is today’s class. In the picture its right in front of the flower, the ripples are actually caused by it

A research team in China have found that water strider legs incorporate thousands of microscopic hairs. Measuring about 50 micrometers—or less than two-thousandths of an inch—long, the hairs are scored by miniature groves. These groves trap air, increasing water resistance of the water's striders legs and overall buoyancy of the insect. The team's research will be published in the journal Nature. "Slight touches or disturbances may break that balance. However, the air cushion at the leg-water interface can [enable] them to locomote quickly and stably on the water surface—even in rainstorms or other disturbances."

Do I still have to tell the similarities… Jesus walked on water 2000 and odd years ago. This is history. He didn’t have air cushioned legs, but FAITH in the Almighty’s power.

Tuesday, June 24, 2008

Praying Mantis

Praying Mantis or preying mantis?!

They are in fact named for the typical "prayer-like" stance. The word mantis derives from the Greek word mantis for prophet or fortune teller. These are funny and sad in a particular way, for during copulation the male dies. The female may start feeding by biting off the male’s head (as with any prey), and if mating had begun, the male’s movements may become even more vigorous in its delivery of sperm. Early researchers thought that because copulatory movement is controlled by ganglion in the abdomen, not the head, removal of the male’s head was a reproductive strategy by females to enhance fertilisation while obtaining sustenance.

If the human kind, the females espl. possess some kind of spell that if any male tries to molest or rape she could order his head plucked off from the base of his neck. WOW.


Dept of Zoology welcomes freshers 2008

This blog is for hard core Zoologist, or anybody who thinks they still exist!

Now im jobless at home, my mom says its bcoz i did zoology. I disagree with her. If i want , I can go for any BPO job and earn a good sum, but if this is the price i have to pay to follow my hearts decision, I will. Since nobody wants to employ me in the dept of zoology, i've created my own!

Look out for funny, interesting facts about the animal kingdom...that includes us too!
Jus to save some time by typing from my text books i will be taking some text from Wiki... forgive me for that part.