Unseen Passage for Class 6 - Passage 19

Sharks are a diverse group of fish known for their incredible adaptability and impressive predatory skills. These fascinating creatures have been around for hundreds of millions of years, evolving into a wide variety of species that inhabit oceans around the world.

One of the key features of sharks is their cartilaginous skeleton, which is lighter and more flexible than the bony skeletons of most fish. This adaptation enables sharks to move with agility and speed in the water. Additionally, sharks are equipped with powerful jaws filled with rows of sharp teeth, allowing them to efficiently capture and consume prey.

Sharks play a crucial role in maintaining the balance of marine ecosystems. As apex predators, they help control the populations of other marine species, preventing overpopulation and ensuring the health of the ocean environment. Some shark species are migratory, covering vast distances in search of food and suitable breeding grounds.

Despite their fearsome reputation, sharks are also vulnerable to various threats, including overfishing and habitat destruction. Conservation efforts are underway to protect these magnificent creatures and raise awareness about the importance of maintaining a healthy and thriving ocean ecosystem.

Flightless birds are a unique and diverse group of avians that have evolved to thrive without the ability to fly. While most birds are capable of flight, some species have adapted to a life on the ground, developing specialized features that suit their terrestrial lifestyle.

One well-known example of a flightless bird is the ostrich, native to Africa. The ostrich is the largest and heaviest living bird, possessing strong legs adapted for running at high speeds. Despite its inability to fly, the ostrich is a powerful and agile runner, using its wings for balance and stability.

The penguin is another fascinating flightless bird, well-adapted to life in the water. Penguins are exceptional swimmers, using their wings as flippers to navigate through the ocean with remarkable speed and agility. While penguins cannot fly in the air, their flying abilities underwater are truly remarkable.

Flightless birds have evolved in various environments, from islands to continents, and each species has developed distinct characteristics to survive and thrive without the need for flight. These birds showcase the incredible diversity and adaptability found in the avian world.