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Week 16th – 22nd September, 2013

How did you do with last week’s  Mystery Creature? It is the Magpie Goose (Anseranas semipalmata)… not native to our Irish shores so a bit tricky for some!

photo credit: Frankzed via photopin cc

This unusual water fowl can be found in northern Australia and southern New Guinea.  With their distinctive black and white plumage these birds are often referred to as pied geese.  Their feet are a striking orange colour, and unlike most water fowl their feet are only partially webbed, their toes are very long and strongly clawed and their legs are so long that they extend beyond their tail when in flight.

Although called geese these birds are classified in a sub family (Anseranatinae) all on their own.  Considered by some as living fossils their ancestors existed more than 60 million years ago.  The evolutionary divergence of the Magpie goose is thought to have occurred long before ducks, geese or swans.

These birds are found in a variety of open wetland areas feeding on seeds and other aquatic vegetation.  They often breed in threes, with the male doing most of the nest building.  Both females will lay their eggs in the same nest (up to eight eggs per female) and all three parents will help raise the young.  They are the only known water fowl to directly feed their young (bill to bill).

Magpie geese make a loud honking sound that can carry long distances over the wetlands.  They molt their flight feathers gradually, removing the need for a flightless period.

Last week the Fun Friday blog was all about density, how less dense liquids will sit on top of more dense liquids and how some liquids such as oil and water do not mix!

What you will need: double cream, salt (optional) a jar with a screw tight lid (preferable plastic!) and a marble (optional)

Add the marble (if using) and the cream to the jar (no more than half full).

Add salt (if using) … we used about half a teaspoon.

Put the lid on tight and start shaking….

….And shaking….

…And shaking!

First it turned to whipped cream, then small lumps of butter started to form!

Keep shaking (about 10-15 minutes) until the butter lumps start to get bigger and clump together and you can see the watery bit separate out.

At this stage you can stop shaking (phew!); now you want to separate the butter from the watery bit (which is actually buttermilk!).

We used clean muslin to separate the butter from the buttermilk, but a few sheets of kitchen roll will work too, or even a clean tea towel.

Squeeze the lump of butter to remove more of the liquid!

Et voila!  You end up with a lovely yellowy lump of butter and some buttermilk (we used our buttermilk for making bread!) You can add salt at this stage instead if you prefer!

We made this!

So what happened (the science bit!)?…

Week 9th to 15th September 2013

How did you do with last week’s Mystery Creature? It was an Antarctic icefish, did you guess it?

Image source: Wikimedia Commons

There are a number of different types of Antarctic icefish but this one is from the Channichthyidae family. These fish are found in the cold waters off the Antarctic, as their name suggests.  They are capable of surviving in waters that often reach temperatures below 0oC in the Winter months.  There are some very unusual features to this fish.  When first discovered in 1927 they were observed to be scaleless fish with pale, sometimes translucent skin.  Further investigation revealed that these fish are unique among vertebrates in that they do not contain any red blood cells.  It appears they lack haemoglobin, a protein used by red blood cells to bind and transport oxygen around the body.  Haemoglobin also binds iron and is responsible for the red colour of oxygenated blood.

So how and why do these fish survive without this oxygen carrying protein? It would seem that this is an accident of evolution, the haemoglobin gene has mutated resulting in a non functional gene, however the fish has managed to adapt and survive.  In order to do this it have developed larger hearts and wider vessels in their circulatory system.  The water within which it lives has high levels of oxygen which it absorbs directly through the body (hence the thin, scaleless skin) as well as through the gills.  Without haemoglobin it carries only 10% of the normal levels of oxygen within its blood.  The cardiac system of the icefish has to work at a much faster rate in order to compensate for this.

Antarctic icefish also produce an antifreeze protein to prevent their ice crystals forming within their bodily fluids under such cold conditions.

Week 2nd to 8th September 2013

A few people got this week’s Mystery Creature right, how did you do? It is the olinguito (Bassaricyon neblina).

photo credit: 禁书网中国禁闻 via photopin cc

This cute little creature is the first carnivorous mammal to be discovered in the Western Hemisphere in the last 35 years.  However they have not been hiding out on us, they have been on display in museums and some zoos for the decades.  The problem is that they were simply mislabeled, thought to be Olingos (a cousin that although similar is larger, with a shorter tail, bigger ears and a longer snout).

Residing in the cloud forests of the Andes this mammal is the smallest member of the racoon family. This arboreal, nocturnal creature is referred to as a carnivore, although fruit makes up most of it’s diet.

The scientific name given to this mammal is “Bassaricyon neblina” where nebulina means cloud and refers to the cloud forests where the olinguito (little Olingo) live. 

Week 19th – 25th August, 2013

How did you do with last week’s Mystery Creature? This unusual looking animal is called a red lipped bat fish (Ogcocephalus darwini) from the Galapagos Islands.

Image source: Wikimedia Commons

This striking looking fish has a number of unusual features…

• this fish is not a very good swimmer and more often will “walk” along the sea floor using adapted fins

• it tends to hunt like the angler fish… luring it’s prey using an organ, called an illicium, that it extends from its head

• it has those amazing red lips… possibly to attract a mate although their exact purpose is unclear

Week 12 – 18th August 2013

How did you get on with last week’s Mystery Creature?  A few people knew this one…. it is a Tardigrade !  Did you get it right?

photo credit: Goldstein lab – via photopin cc

The tardigrade… often commonly called a water bear or moss piglet) is a very small but very interesting creature.  My son spent the whole of last week telling anyone who would listen about “the toughest creatures on Earth”!

These little animals are usually about 0.5 to 1.2 milimetres in length, which means they are may be just visible to the naked eye but can easily be viewed under a low powered microscope.  They are water dwelling organisms found in both marine and freshwater habitats.   They are commonly found on lichens and mosses and must be surrounded by a film of water to prevent them from drying out. Tardigrades can be found in every continent of the world and in some very extreme enviornments.

These water bears are very cute little microscopic creatures, they have short, plump, segmented bodies with four pairs of lobopodial limbs (poorly articulated) with four to eight claws at the end of each.  These small invertebrates move in a slow lumbering fashion, hence the name water bear.

Tardigrades feed on the fluids of plant or animal cells.  Some species are even know to feed on other tardigrades.  They pierce the cell wall and then ingest the fluid via a sucking pharynx.

There are a number of amazing features about these micro animals that have made them the interest of many studies over the years….

Tardigrades are extremophiles:

• They can (for a short period of time) survive extremes of temperatures from -200  up to 150 degrees Celcius;

• They can withstand pressures up to 1,200 times atmospheric pressure or the very low pressures of a vacuum;

• They can withstand extreme levels of radiation – up to 1000 times the levels that would be lethal to most animals;

• When exposed to environmental extremes they reduce their metabolic rate down (just 0.01%) to an almost death-like state  called cryptobiosis. 

• In 2008 a number of tardigrades were launched into outer space for ten days where they were exposed to extremes of temperature, UV radiation from the Sun, the vacuum of space and dehydration.  Amazingly, some of these creatures survived the ordeal and even went on to successfully reproduce.

• They are the only creatures able to survive being photographed by a Scanning Electron Microscope (SEM) (which bombards them with a stream of electrons while placed within a vacuum).

It is easy to see now what my son was talking about;  I am as impressed with these little creatures as he is.  I imagine we will be going on a “Tardigrade Hunt” before the Summer holidays are out and we will see how they look under our family microscope.

If we have any luck I will be sure to share it all here!

What is Forensic Science? 

Forensic Science is the investigation of a crime using different scientific techniques.

photo credit: Alan Cleaver via photopin cc

Let‛s learn more! 

When a crime is committed Forensic Scientists help collect the evidence. They may use Chemistry, Genetics, Biology, Pathology, Entomology and Toxicology to examine the clues. Some of the evidence gathered at a crime scene could include hair, skin cells, fibres from clothes or carpets, footprints, fingerprints and blood samples.

DNA can be extracted from hair or skin cells found at the crime scene and can be used to link a suspect to a crime.

photo credit: BWJones via photopin cc

Hair and fibre samples found at crime scenes can also give vital clues to solving the crime. These samples can be viewed under high powered microscopes. Hair samples can give an idea of a person’s age, general health and hair dyes or hair styling products can also be identified.

Forensic chemistry techniques can reveal a lot about fibres such as the type of dye used, the type of fabric, where the clothes were made.

Fingerprints

Image source :Wikipedia

There are two types of fingerprints usually left at a crime scene:

1. VISIBLE PRINTS: you can see these prints with your own eyes 
2. LATENT PRINTS: you may not be able to see them but they are left due to sweat or oils on the skin.

Some surfaces are difficult to lift fingerprints from.  In such cases a flourescent powder is used to bind to the organic matter in the fingerprint and the print is then visible under UV light.

Forensic Ballistics

Forensic ballisitcs is the examination of bullets and firearms in order to identify the weapon used in a crime.

Forensic Entomology

By working out how old the maggots are the scientist can determine how long the body is dead.

photo credit: Ewan Bellamy via photopin cc

Experiments you can try!

1. Make a fingerprint

You will need.. a glass, a soft brush (like a make up brush), cellotape, cocoa powder, white paper

What to do... rub your finger on your scalp then push the pad of your finger onto the side of the glass. Use the soft brush to gently cover the fingerprint with cocoa powder. Take a piece of cellotape and place it over the fingerprint.  Carefully peel back the cellotape and stick it on to the white paper.  You should be able to see your fingerprint.  Now try and describe your finger print by comparing it to the chart below;

So what is happening? When you rub your finger on your scalp it covers your finger in natural body oils.  When you push your finger to the glass the oils transfer the pattern of your fingerprint to the glass.  Adding the cocoa powder lets us see the print.

4th – 11th August 2013

How did you get on with this week’s Mystery Creature?  A beautiful moth … but did you know which one?  It is the Garden Tiger Moth (Arctia caja).

This beautiful moth is common enough in Ireland and indeed throughout Europe.  It is often seen in gardens from June to August, although more commonly seen flying at night.

Underneath these beautiful front wings are equally impressive back wings of striking orange colour with black spots. If disturbed the moth will flash these back wings before flying off which both confuses predators and warns them that it is toxic.

The colourful back wings often hidden when at rest; photo credit: Deanster1983 via photopin cc

Fond of damp habitats these moths tend to favour, damp grasslands, gardens, hedgerows and woodlands.  The caterpillar (larval stage) feeds on common weeds such as nettles and dock.

Tiger Moth Caterpillar – photo credit: Deanster1983 via photopin cc