Science in Everyday Life is a series of
11 books written in simple English and illustrated with relevant
pictures and diagrams to enhance the general knowledge of science.
The content of each book in the series
are designed to excite and motivate the readers to develop a keen
interest in the phenomena of everyday sciences.
What does an octopus do when it is spotted by a predator? Its main defence is to hide, either not to be seen at all, or not to be detected as an octopus. However, the most common defence is fast escape. Other defences include the use of ink sacs, camouflage and autotomising of limbs (detaching its limbs).
An octopus' camouflage is aided by certain specialised skin cells which can change the apparent colour, opacity and reflectiveness of the epidermis. Chromatophores contain yellow, orange, red, brown or black pigments. Most species have three of these colours while some have two or four. Other colour-changing cells are reflective iridophores and leucophores (white). This colour-changing ability can also be used to communicate with or warn other octopi.The poisonous blue-ringed octopus becomes bright yellow with blue rings when it is provoked. Octopi can use muscles in the skin to change the texture of their mantle (surface layer) to achieve a greater camouflage. In some species the mantle can take on the spiky appearance of seaweed or the scraggly, bumpy texture of a rock. However, in some species the skin structure is limited to relatively patternless shades of one colour and limited skin texture.
Let's view the following clip on the different camouflages of the octopus.
Test Your Science 1. How is the octopus able to camouflage itself from its predator?
Get to know the Best Camouflaged Creatures in the forest in the Young Scientists Issue 117 Level 1.
Do you know that the lotus or the Nelumbo nucifera is currently recognised and placed in its own order known as Nelumbonales? This plant is an aquatic perennial. A common misconception is referring to the lotus as a waterlily (Nymphaea), an entirely different plant as can be seen from the centre of the flower which clearly lacks the structure that goes on to form the distinctive circular seed pod in the lotus.
The distinctive dried seed heads which resemble the spouts of watering cans are widely sold throughout the world for decorative purposes and for dried flower arranging. The flowers, seeds, young leaves and roots (rhizomes) are all edible. In Asia, the petals are sometimes used for garnishing while the large leaves are used to wrap food. Lotus roots are rich in dietary fibre, vitamin C, potassium , thiamin, riboflavin, vitamin B6, phosphorus, copper and manganese while very low in saturated fat. The stamens can be dried and made into a fragrant herbal tea or used to add a scent to tea leaves.In Myanmar, the lotus plant fibres are used to produce a unique fabric for weaving special robes for Buddha images.
Get to know the water lily and the lotus in the following clip.
Test Your Science 1. What makes the lotus a very useful plant?
Find out more about the Lotus in the Young Scientists Issue 117 Level 2.
Have you ever heard of the alpaca? It is a domesticated species of South American camelid. It resembles a small llama in appearance. Alpacas are considerably smaller than llamas and unlike llamas, they are not bred to be beasts of burden. They are bred specifically for their fibre. Alpaca fibre is used for making knitted and woven items, similar to wool. These items include blankets, sweaters, hats, gloves, scarves, a wide variety of textiles and ponchos in South America, as well as sweaters, socks, coats and bedding in other parts of the world.
An adult alpaca is generally between 81 and 99 cm in height. They usually weigh between 48 and 84 kg. Alpacas are social herd animals that live in family groups consisting of a territorial alpha male, females and their young. Alpacas warn the herd about intruders by making sharp, noisy inhalations that sound like a high-pitched bray. The herd may attack smaller predators with their front feet and can spit and kick. Most alpacas do not like being grabbed. Some alpacas tolerate being stroked or petted anywhere on their bodies although many do not like their feet, lower legs and especially their abdomen to be touched or handled.
Watch the Suri Alpacas in this clip.
Test Your Science 1. State the difference(s) between the llama and alpaca.
Learn about the Llama in the Young Scientists Issue 117 Level 3.
