1 / 68

SAMMY SNAIL

SAMMY SNAIL. A snail’s life. All snails begin like this. They begin as eggs . When they hatch out they are soft but even then they have a soft shell that hardens quickly. BURIED EGGS. You can see three small balls we think they are snail eggs. Weird but true.

torn
Télécharger la présentation

SAMMY SNAIL

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. SAMMY SNAIL

  2. A snail’s life. • All snails begin like this. • They begin as eggs . • When they hatch out they are soft but even then they have a soft shell that hardens quickly.

  3. BURIED EGGS. • You can see three small balls we think they are snail eggs.

  4. Weird but true Every adult snail can lay eggs. Snails are hermaphrodites . • The snail lays about 50-80 eggs in a nest, about 3cm. deep in the soil. • They hatch out in about 3 weeks. • The temperature must be about 12°C for eggs to hatch.

  5. The smallest snail we found.

  6. Life for one year. The tiny snail has a soft shell at first then it hardens It just eats and eats for the next year. The shell gets thicker. They hibernate in winter and in dry weather.They eat mostly at night and love damp warm weather.

  7. Who has been eating my flowers? Snails are plant eaters only.

  8. Different sizes. We found these five different size shells in our gardens. They range from a few months to 3years.

  9. Length • It is hard to measure an adult snail . • On average it is about 70mm. long. • Baby snails are about 5 mm. long .

  10. An adult snail • It can live for up to five years . The best time to find them is May to September. • It takes one year for a snail to get to adult size. The proper name for a snail is HELIX ASPERSA. It is a gastropod which, in latin, means belly foot. This is an adult garden snail.

  11. How to recognise an adult.? • An adult snail at about one year old begins to grow a lip at the base of the shell. • It looks like a soldier’s helmet. • Shells have an inner layer.

  12. Four horns • The top two are eyes. They are about a centimetre long. If you touch an eye it can pull it in instantly. • The bottom two are shorter and always close to the ground. It can sense vibrations and smell with them.

  13. THE EYE (x10) • The eyes are on the tops of its horns. We don’t know how good their eyesight is but they always know the difference between light and shade .

  14. Retractable Eye • A snail can pull in its eye at any time. • One or both together. • This protects the eye and can keep the pupil moist. • It has no eye lash or eye lid. • It can also retract its lower feelers. • It also makes it easier to squeeze into its shell.

  15. Social Creatures Snails are social creatures. They don’t mind climbing on top of each other. You will very seldom find them alone . They will always share their space with each other.

  16. Great pets • Snails are not afraid of people. They will nest quite happily in children’s hands.Sammy is Niamh’s pet.

  17. The shell. The snail says alas! The snail says alack! Why must I carry my house on my back? Good question!

  18. Two Reasons • Its biggest fear is that its body will dry out in the sun and wind.It needs liquid for the slime. • It can’t run away quickly from its enemies so it needs a place to hide instantly if it is in danger of being attacked.

  19. How does the shell grow? • The snail makes its shell bigger by adding layer after layer of new shell at the opening of the shell. • The ridges are like the rings on trees. • Its like a slinkey where each ring is slighty bigger than the last. • You can see the layers here.

  20. A shady place. Snails hide in places like this during the bright days. They can stay this way for more than a week in the shade if the weather is too warm and dry.They don’t have to eat every day.Wet nights are heaven for them.

  21. Day or night? • How does a snail inside a shell know if it is day or night? • This is what it is like inside a shell in sunlight. • We shone a light though the shell in a microscope.

  22. No two shells have the same pattern.

  23. Snowy mountain. • This is not a snowy mountain. This is a close up of an old snail shell.The shell has been bleached by the sun and the white colour shows what it is made of.(calcium)

  24. Regular Whorls. • Of all the shells we tested we found that each whorl is roughly three times wider than the last one in adults. • If you draw a diagonal line from the centre to the lip you will nearly always get 2mm. 6mm.18mm. for the outside three whorls.

  25. Snail graveyard • This is an old slate leaning up against the south facing wall of a flower garden . • All these snail shells are empty. They may have died during the cold weather of winter or maybe of old age. • This slate has been here for at least 20 years.

  26. Eventually Shells will lose their stickiness and fall to the ground. Sometimes snails eat bits of these old snail shells Hens do the same thing with egg shells.

  27. How heavy is a shell. • A snail shell may feel light to you but if you were a snail your shell would be about • 25%-30% of your total weight.

  28. Lighter than an egg shell

  29. Shell volumes We crushed the shells We measured their volumes like this. 6.c.c1.8c.c.

  30. Light but strong This shell was able to hold up a 6.5 kg sledge when placed on top of the shell. But if you place the shell on its side and place even half that weight on it it will crush easily.

  31. On its side • This is what happened when we placed the shell on its side we put 1.8kg hatchet on the edge. • It crushed easily. • The birds still find it hard to crush the shell.

  32. Central pillar • This pillar from top to bottom is what gives the shell its strength. • It is not half as strong from side to side. • This is what allows the bird to break the shell.

  33. The Anvil. • They have learned a trick. • They use a stone to bash the shell against. • It has a sharp edge which makes it easier to break the shell. • Even so we have found only the remains of small shells there.

  34. How a snail comes out ? • They don’t screw out or in. • They just fold out and in. • The top third of the snail is like a camel’s hump but it is stuck to the top spirals of the shell.It is never exposed. • If you find an empty shell its owner is dead.

  35. Emerging Snail • This is how a snail looks just before it emerges. • It can be very hard to get them to come out, but, if you dip the base in water they will come out shortly.

  36. Wakey! Wakey! • First two folded flaps come out and open.

  37. Is it safe to come out? • Then the head appears from under the edge of the shell. • You will only realise this when a little horn pops out. • This is a quick peep. One eye first.

  38. Unfolding. • Next comes the second eye. • The body unfolds more.

  39. Almost Open • Now he is ready to put out his tail. • Once his tail is out the rest is easy.

  40. Finally out • This is what he is like when he is out. • You can just see his curved mouth. You can see how moist his body is.

  41. OUT FOR A WALK • Snails are not stiff like sausages. They can stretch and bend and twist any way they want. • They move more like an octopus than any other creature.

  42. Slime • A snail can not live without slime. • It needs it to smooth the path for itself. • It also stops tiny creatures from taking a juicy bite. • The slime hardens in contact to air.

  43. Trails • They can follow their own trails back to their hiding places because the trails can last a long time. • They can follow other trails to meet their friends.

  44. Sticky slime • One day Sammy was exercising. He climbed up on a 20 gram weight.We lifted Sammy,the 20 grams came with it. • Snails can stick to anything in any position.

  45. Super glue • When the slime hardens after a few hours it is like super glue • You can see some hard slime in the middle of the picture

  46. Glue test • It took a force of 150 grams. (1.5 Newtons) To remove the shell from the wall. • This did not harm the snail • One shell took 2 Newtons to remove

  47. Gluey Rim • The snail was not harmed by this pull because the snail’s body is above the gluey rim

  48. How Snails Breathe • Snails breathe through a hole in the bottom of their bodies.They need to breathe all the time even when they hibernate.We got this picture from a book. “SNAIL WATCH IT GROW” • By Barrie Watts

  49. How fast can a snail move? • This is not easy to find out because------ • They might not move when you want . • They don’t go in a straight line. • This is how we solved the problem

  50. Tracking the snails • We kept a primrose leaf in front of them as bait to keep them moving . • We placed them on a white sheet and follow their trail with a red pencil • We timed four snails for 5 minutes each

More Related