(Dr. Girish Chandra)
The bull shark, Carcharhinus leucas, also known as Zambi in Africa is a common worldwide species found in warm shallow waters along sea coasts and in rivers. The Bull shark can thrive in both saltwater and freshwater and can travel far up into the rivers.
Whale shark (Rhincodon typus) is world’s largest fish measuring up to 45 feet in length. With the exception of the Mediterranean Sea, whale sharks can be found in all temperate and tropical oceans around the world and migrate thousands of miles in search of food. The shark has yellowish stripes and dots on its dark gray skin. The whale shark is a filter feeder and can neither bite nor chew but filters planktons and small shrimps by its gill rakers. Whale sharks are slow swimmers, moving at speeds of no little more than 3 miles per hour.
Great White Sharks (Carcharodon carcharias) are the largest predatory fish in the sea. Great White sharks live along the coasts of all continents except Antarctica. They have an enormous liver that can weigh up to 24 percent of its entire weight and their bodies can grow up to 20 feet long. The shark’s back may be dark blue, gray, brown or black. A Great White Shark is capable of eating the sea lions whole but they are no match for Killer Whales which hunt in packs and are too fast and agile.
Latimeria chalumnae is the sole surviving Crossopterygiian coelacanth and Latimeria menadoensis is the Indonesian species. The coelacanths were thought to have gone extinct about 65 million years ago. The first specimen was netted off South Africa in 1938, a catch that shook the scientific world and was widely regarded as the zoological find of the 20th century. Coelacanths can reach almost 1.5 m in length and weigh up to 68 kg. Coloration is dark blue to steel grey or tendst o be more brownish. Latimeria has a single, large, elongated, pseudo-lung, shark-like intestine with a spiral valve.
The two families of lungfishes are Lepidosirenidae (South American lungfish and African lungfish) and Ceratodidae (Australian lungfish). All species have elongated bodies. All species of lungfishes grow large and the African lungfish can become over 6 feet long. Lungfishes are predators and will eat fish, crayfish, crabs etc.
African lungfish, Protopterus
South American lungfish, Lepidosiren
Australian lungfish, Neoceratodus