Thursday, 28 November 2013


Enjoy this presentation I have made with this lovely collection of photographs of the sky taken by Marta Hernani from ESO 2.

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.

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

It is found in AlgeriaItalyMoroccoPortugalSpainGibraltar and Tunisia.


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]


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.


  1. Boulenger, G.A. 1893. Catalogue of the Snakes in the British Museum (Natural History), Volume I. London. pp. 409-410.
  2. Arnold, E.N. & J.A. Burton. 1978. A Field Guide to the Reptiles and Amphibians of Britain and Europe. Collins. London. pp. 191-194.

Saturday, 16 November 2013


 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
 Here are some pictures of how we set up the habitats. Birdseeds grow very fast and they made a quick plant environment for the animals.

Water and gravel
Soil for the top floor
Birdseeds growing
A collection of ecosystems
A balanced ecosystem
Larvae on a potato plant leaf
 One group added some larvae that they found growing on the potato plants of another experiment we had in the class. Shortly after, the larva changed into a pupa and formed a cocoon in a corner of the bottle and began metamorphosis, After some time we were able to see the pupa change into a moth. In the following photos you can see how it transforms!

Larva in the ecosytem
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
Pupa on the curtain
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!!
Look at the following photographs and observe the transformation. We were able to see metamorphosis!
Pupa begins metamorphosis
Moth leaves coccoon
Moth leaves coccoon 

 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
 Another natural event that took place in one of the ecosystems was performed by a beetle. This animal destroyed all the plants in the top floor and rolled them into a big ball. The beetle covered itself with it. Some beetles feed on this matter when it begins to decay. The students of this group were very surprised to see how their terrestrial ecosystem had disappeared in a day!! Here you can see the big ball of plants and soil surrounding the beetle.

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
Students working on their ecosystem
Making the ecosystems
The students thoroughly enjoyed this experiment!!


Enjoy these slides that contain our interesting collection of nature spotting photos! 

Thursday, 7 November 2013


 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.

 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.

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!

·       Revista national geographic (de mi casa) : el mundo debajo del agua