Colours of the Undersea

Colours of the Undersea

Life under the surface of the sea is very different from on land. All the features of sea-dwelling creatures are organised in such a way as to enable them to live in water in the easiest way possible. Humans cannot see in water as well as do fish, because the human eye does not have the features that would allow it to attain sharp eyesight underwater. The human eye does not have a lens system such as that of the fish, and is not spherical and hard like that of a fish, so it does not have as sharp sight underwater as the fish. It cannot allow as precisely as fish do for foreshortening of distances in the water due to refraction, as it cannot estimate the refraction of light in water.

Allah has created every living being with the most suitable characteristics for the environment it inhabits. Creatures living under the sea constitute only a small part of the examples of Allah's artistry in creation. Allah has no partner in creation and everything is under His control.

There is no other god besides Allah. Allah - He is the Almighty, the All-Wise. (Surah Al 'Imran: 62)

A shrimp moves undisturbed along the surface of a sea anemone. The transparency of these small crustaceans is extraordinary, because in most transparent animals some major part of the body still remains visible. For example, most cannot manage to conceal their digestive systems and the food contained inside them. In some species, only the tail and a part of the pincers are coloured. These small details of colour are useful in enabling the shrimp to "disappear"; the contrast between the transparent parts and the colourful markings is so pronounced that would-be predators are drawn to the markings themselves and are not able to perceive the over-all outline of the animal.42

The photograph on the left belongs to a rock lobster. This lobster, a perfect example of harmony in colour and design, is adorned with shades of red.43Above is a coral. Billions of corals lie together. They combine with each other by special secretions, and form a limestone skeleton. On this skeleton, they secrete a coloured substance: red, pink, and occasionally black or white.

In the depths of the sea, starting from 200 metres below the surface, there is no light at all. However, when reaching the bottom of the oceans, which are even deeper than the height of Everest, we come across a multicoloured world. The striped anemone fish, which live in anemone plants, seen in the photograph above, are also members of this world.

Sea cochlea (Nudibranches) is one of the most interesting animals of the underwater world. With their interesting designs and extraordinary colours, these animals are a species of cochlea without a shell. On the pictures above are examples of a few species. These creatures, which have soft bodies, are protected by a strong poison. Their striking colour warns their predators that they are very poisonous. They obtain their poison from the plants they eat.44

The body of the seahorse is covered with plaque-shaped bones. Seahorses are not very good at swimming. For this reason, they live by clinging to corals. Since seahorses can change their colour quickly, they are easily protected from their enemies.	One of the most curious and useful features of molluscs is their so-called "cloak" - the tissue that covers their bodies and forms a "second shell". As the photograph reveals, the cloak slowly covers the shell and interrupts the chromatic uniformity that could betray the animal's presence.45.	Spider crabs are remarkably diverse in size and shape. They range from gigantic Japanese Spider Crab, with metre-long legs, to the miniature coral-reef species seen above. Their patterns blend remarkably well will the poly-studded texture of their hosts.

Scorpion fish live along the seabed in temperate or tropical zones and never venture out to open sea. They are carnivorous and feed on smaller fish. The long, fan-shaped pectoral fins are an excellent deterrent to the fish's enemies, and the red-and-white stripes make it difficult for their prey to see them against a backdrop of coral.46 Scorpion fish have a very colourful appearance but can easily become invisible among the corals, which are also very colourful.

The members of the Soleidea species, such as soles and rhombuses (above), are extremely mimetic. Their benthic (i.e., bottom-dwelling) nature forces them to imitate the substratum as much as possible. The crocodile fish (below) uses its colour to hide from predators.47

Crinoids, seen on the photograph, are sea tulips in the shape of lilies. They have long, thin, flower-like spiked arms. There is poisonous mucus on their arms. They absorb the oxygen in water through their arms by filtering it.49

An octopus, photographed at night, makes its skin flare to appear larger. This iridescent green colour is seen almost exclusively after dark.48 Some species can become at one with the deep-sea underwater patterns.

The mantis shrimp (seen on tle left) is only one of the creatures of the undersea that has an interesting appearance and bright colours. Its protruding eyes are among the most complex eyes in nature. (Seen on the right), are painted prawns, which live amid the spines of a poisonous sea urchin.50

42. Marco Ferrari, Colors for Survival, Barnes and Noble Books, New York, 1992, p.55
43. National Geographic, October 1989, p.518
44. The Guinnes Enyclopedia of Living World, 1992, p.167
45. Marco Ferrari, Colors for Survival, Barnes and Noble Books, New York, 1992, p.56
46. Marco Ferrari, Colors for Survival, Barnes and Noble Books, New York, 1992, p.122
47. Marco Ferrari, Colors for Survival, Barnes and Noble Books, New York, 1992, p.62
48. Karl Roessler, Coral Kingdoms, Harry N. Abrams, Inc., Publishers, 1986, p.44
49. National Geographic, December 1996, p.118-120
50. Karl Roessler, Coral Kingdoms, Harry N. Abrams, Inc., Publishers, 1986, p.125