Enjoy this presentation I have made with this lovely collection of photographs of the sky taken by Marta Hernani from ESO 2.
Blog designed for my science students but also open to anyone interested in basic experimental science. A place to read more about science, go over the experiments we do in the class, read about new and old science discoveries, publish your topics and projects and lots more.
Thursday, 28 November 2013
Saturday, 23 November 2013
How does a starfish move?
The ambulacral system is a water vascular system used for movement in echinoderms. It consists of numerous tubes inside the body and many other tubes that make up the ambulacral feet . The tubes are connected to tiny muscles that control the flow of water inside them. Contracting these muscles water is forced into the tubes and into the feet causing them to extend. Relaxing these muscles empties the tubes allowing the feet to retract. Starfish and other echinoderms move slowly using this hydraulic system.
Many questions arose when we talked about this in the class. Here is a great video in which you can see how a starfish moves by moving its tiny ambulacral feet.
Many questions arose when we talked about this in the class. Here is a great video in which you can see how a starfish moves by moving its tiny ambulacral feet.
Our starfish, top side |
Our starfish, underside |
Starfish and ophiura |
Thursday, 21 November 2013
A horseshoe whip snake in the class!!
We've had another visitor in our class this year. One of my students found and brought a horse shoe whip snake to the class. This snake is very common in the area. It's scientific name is Hemorrhois hippocrepis. We looked after it for about 2 months and after this time we decided to set it free. It was interesting to see the snakes external anatomy, its scales, the pattern on its skin, its wide head, its big black eyes. We were also able to observe its behaviour. It's a fast moving snake, able to raise its body easily.
Watch this video of our snake!
Here is some more detailed information about the horse shoe whip snake taken from Wikipedia.
The horseshoe whip snake (Hemorrhois hippocrepis) is a species of snake in the Colubridae family.
Geographic range
Description
Adults may attain a total length of 1.5 m (5 feet). Its body is slender, and its head is wider than its neck. The eye is large, with a round pupil, and with a row of small scales below it. The smooth dorsal scales are arranged in 25-29 rows, and the ventrals number 220-258. Dorsally it has a series of large spots which are either blackish or dark brown edged with black. There are series of alternating smaller dark spots on the sides. The lighter ground color between the spots may be yellowish, olive, or reddish. The dark spots are closely spaced, giving the appearance of a dark snake with a light pattern resembling a chain or a series of X's. There is a light horseshoe-shaped mark on the neck and back of head.[2]
Habitat[
Its natural habitats are Mediterranean-type shrubby vegetation, rocky areas, rocky shores, sandy shores, arable land, pastureland, plantations, rural gardens, and urban areas.
Conservation status
It is threatened by habitat loss.
References
- Boulenger, G.A. 1893. Catalogue of the Snakes in the British Museum (Natural History), Volume I. London. pp. 409-410.
- Arnold, E.N. & J.A. Burton. 1978. A Field Guide to the Reptiles and Amphibians of Britain and Europe. Collins. London. pp. 191-194.
- Miras, J.A.M., Cheylan, M., Nouira, M.S., Joger, U., Sá-Sousa, P. &Pérez-Mellado, V. 2005. Hemorrhois hippocrepis. 2006 IUCN Red List of Threatened Species. Downloaded on 28 July 2007.
- List of reptiles of Italy
Saturday, 16 November 2013
MAKING AN AQUATIC AND A TERRESTRIAL ECOSYSTEM
So many
things happened in the class when we did this experiment! We were lucky to see
many natural processes occur in front of our eyes!
To set
up the ecosystems we used two plastic bottles. One, for the aquatic ecosystem
and one, for the terrestrial ecosystem. We cut them both and filled the bottom
bottle with gravel and water. We added gravel and soil to the top ecosystem and
also some birdseeds. Once the habitats were set up each group was free to add
any living thing they could find and bring. By doing this all sorts of things
happened before are eyes!
Making the bottom floor |
Making the top floor |
Water and gravel |
Soil for the top floor |
A collection of ecosystems |
A balanced ecosystem |
Larvae on a potato plant leaf |
Larva in the ecosytem |
Coccoon |
Spider weaves its web over the coccon |
Metamorphosis begins |
A spider that was also in the same ecosystem
placed itself next to the cocoon and stayed there for several days. We thought
it was probably waiting for the adult to emerge from the cocoon and to trap it
as soon as possible. It also made a web over the cocoon! So we didn’t just see
the larva changing into a pupa, we saw also saw a spider weaving its web!
Pupa in a leaf |
The larvae made cocoons in other parts of the ecosystem. In this picture you can see how it has bent a leaf for protection.
Pupa in a leaf |
We also found a cocoon out of our ecosystems!!!
Here is one on the classroom curtains …this is wildlife in the class!!
A closer view of the pupa on the curtain!! |
Pupa begins metamorphosis |
Moth leaves coccoon |
Moth leaves coccoon |
Moth |
Moth |
Another metamorphic process that occurred was
the transformation of mosquito larvae into mosquitoes. One of the groups of
students brought many mosquito larvae from an abandoned swimming pool and they
added them to the bottom floor of their experiment. Many students were
surprised to see that mosquitoes emerge form the water! This is because their
larvae are aquatic. Many students had seen these larvae before but didn’t know
they were mosquito larvae!
Mosquitoes just after metamorphosis and mosquito larvae in the water |
Mosquitoes leave the aquatic ecosytem |
We were
able to see perfectly how the larvae left the water as adult mosquitoes. There
were so many in the bottle that every day we had to set some free.
Beetle begins to roll the vegetation |
Beetle rolling the plants |
In the
following pictures you can see different living things in the ecosystems.
Snails, geckoes, grasshoppers, worms,
flies, fish etc.
Grasshopper on the ball of plants and soil made by the beetle |
Grasshopper |
Students working on their ecosystem |
Snail |
Snail |
Fish |
Gecko |
Beetle |
Fish |
Observation |
Observation |
Making the ecosystems |
NATURE SPOTTING COLECTION!
Enjoy these slides that contain our interesting collection of nature spotting photos!
Thursday, 7 November 2013
SCIENCE FAIR PROJECT - FISH - By Rafael Marcos
FISH
Fish are vertebrates aquatic animals,generally poikilotherms,
most of them are covered with scales and have fins,
that permit them to move in the water and gills, which trap the oxygen in the water.
Fish are
found in salt and in fresh water, for example the gudgeon, that lives in rivers in
the mountains, and they also live in the deep ocean, like gulper eels.
SALMONS
When salmon
appeared on Earth isn’t known for sure; however the information that
exists permits scientists to know that “Teleosts ” the group of
fish which salmon belong to, dominated
the water in the Cretaceous period that started
135 millions years ago. At the same time dinosaurs and other giants
animals inhabited the Earth and even the oldest ancestors of humans appeared.
The life cycle of a salmon:
The salmons are
born from eggs and live in the river. After some time they go to the sea and when they become adults, they go back to
the river to lay more eggs. The female lays the eggs and the male fertilizes
them. Once they lay their eggs, they die.
MORE EXAMPLES OF FISH
Hippocampus histrix
The Hippocampus histrix is a type of sea horse
they generally live in the sea , they come from the Indian oceanic but we can
find them too in the Read
Sea or the Arabic sea. The
Hippocampus histrix can be 15 cm in the adult age. Its body is S shaped, like
most sea horses.
The
yellow tail lady
The yellow tail lady originated in the coral reef of the Pacific
ocean . They can grow upto 15 cm. They are a blue electronic colour
with a yellow tail. Their body shape is long and flattened, like most of
ladies.
El hypanicistrus zebra
The Hypancistrus zebra is from Brazil , from the river Xingu .
They can be from 5 to 10 cm long. Their body is flat and long, they’ve got a
little mouth.
My experiment also showed the internal and external
features of fish. For this I placed a sea bass on a tray. I indicated the
external features like scales, fins, lateral line, operculum, eyes, mouth etc.
With some tweezers I opened the operculum to see the gills. The gills are very
red because they are full of capillaries with blood, ready to trap the oxygen.
I also prepared
a fish tank with fish and aquatic plants to indicate the natural gas exchange
between them both producing a balance in the ecosystem.
Watch this video of our fish tank!
Bibliography:
·
Revista national geographic (de mi casa) : el
mundo debajo del agua
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