Nature's Greatest Moments

- Season 3

(2001)

Rays look completely different to other fish, they spend most of their time at the bottom of the ocean, sometimes even under the sand. Many rays also give birth to live young a few months after mating, rather than laying eggs. There are about 500 species in various parts of the ocean and although their appearance differs widely, there is one thing all rays have in common - the ability to fly.

Sharks are the perfect predators - and some of the most ancient creatures in the ocean - The most dangerous is the great white, the largest predatory fish in the sea, which can reach a length of 6 metres. Despite its fearsome reputation, the great white is not an insensitive human-killing machine. It is an intelligent hunter, equipped with acute senses of smell and sight. It plays an essential role in the ocean's food web and is worthy of respect - rather than fear.

Sharks are ancient predators, but this does not mean that they are primitive. They have well-developed brains and an array of acute senses. Their design is so well-adapted to their lifestyle that they have barely changed for the past 70 million years. Apart from an acute sense of sight, sound and smell, sharks have the unique ability to detect the weak electrical field generated by all living organisms and can even sense a fish buried under the sand. With their exceptional senses and brilliant body design, sharks are the great survivors of the ocean - and they rarely ...

There are many peculiar sharks that look nothing like the conventional image of a shark. The whale shark is the largest fish in the sea. It grows up to 18 metres with a weight of 40 tons. One of the most bizarre sharks is the wobbegong, which instead of chasing after its prey, it uses its clever camouflage to wait in ambush for fish to pass. The elephant fish uses its odd trunk-like nose to locate shellfish. It has a naked skin, with no scales like fish or denticles like sharks. When it comes to sharks, variety is the spice of life.

Dolphins are the best-loved creatures of the sea. They are also some of the most intelligent and the most sociable. They communicate with each other using their special language of clicks and whistles. Each dolphin has its own 'signature' whistle that the others can recognise. The bonds between family members are very close, especially a mother and baby which can last for up to six years. Dolphins are also some of the ocean's top predators. When they track the annual sardine run down, they work together as a team to feed on them. This is the event of the year for the ...

In the dangerous underwater world the easiest way to disappear from sight is to blend in with the reef. Creatures such as octopus and stonefish have perfected this art. The first to escape being eaten and the other to surprise potential prey. Deception on a crowded reef could mean the difference between life and death, butterflyfish have large spots that look like eyes near their tails to confuse a pursuing predator. In this episode we explore the different ways of camouflage and ways in which fish deceive both hunter and prey.

The vast ocean can be a dangerous place for many sea creatures, large and small. Some have taken to hiding in caves for protection. Caves are perfect hiding places for juvenile fish. The dark interiors provide a perfect resting place for fish which prefer to come out at night. Morays eels use the smallest of caves to their advantage, hiding in them and rushing out to catch unsuspecting passing prey. Caves are also used by sharks that can breathe while at rest, like the whitetip reef shark and the tawny shark.

Coral reefs form wonderful and beautiful underwater worlds but they could also be the curse of the sea to unsuspecting mariners. One careless naval move and their ship runs aground and sinks. Once the wrecks reach the bottom of the ocean they are slowly colonised by sea creatures. We look at the animals that live on and around the wrecks of the Red Sea.

The whale shark is the largest fish in the sea. It roams on secret highways through following the currents of the ocean, drifting in perpetual search for food. It is a magnificent and mysterious creature, yet despite its size it is a gentle giant which allows divers to get close to it. (We can show size by including a few diver shots)

The strangest looking shark is the hammerhead. But its odd-looking head is well equipped with incredible sensory organs used by the shark to detect the presence of food or danger. We observe a squadron of hammerheads as they glide over a reef in the Red Sea.

The oldest living reptiles, more ancient that the dinosaurs, live in the sea. They are the turtles. Five species occur in the Indian Ocean. We follow one of them - the loggerhead, as it returns to its beach of birth and lays a precious clutch of eggs. Once the eggs hatch the little turtles face many perils on the beach and in the ocean.