Freshwater crocodiles ( Crocodylus palustris ) are mainly found in freshwater water bodies such as rivers, canals, beels and mountain streams. Even at one time these were in ponds and ditches of Bangladesh.There was always something that was quite scary. This reptile is also notorious for taking human cows and goats from hiding in ponds. Although today this species is extinct in Bangladesh. Due to the increase in fishing, many crocodiles get trapped in the nets and die. This crocodile is lost from the natural environment in the evolution of time.
Although the name is freshwater crocodile, they can swear even in salt water. They are usually located at a depth of 5 meters in the water. They make holes of different shapes near the water bodies and stay in them. They do not migrate seasonally but live in the same place during monsoon and dry seasons.
Freshwater crocodiles are about 4-5 meters in length and weigh up to a maximum of 600 kg. Their whole body is covered with rough scales which are very muddy in color. Of all the species of crocodiles, their beak is the widest. Apart from their morphological features, there is no physical difference between male and female crocodiles. Male crocodiles tend to be slightly larger than female crocodiles.
Their cubs are around 0.26 meters in length and weigh about 300 grams. If they weigh 3-30 kg, they are considered as young crocodiles. When young, they grow up to 1.4 m long.
The female crocodile usually lays up to 25-30 eggs. They need optimal temperature and humidity to grow well. It has been recorded that they need a temperature of exactly 36 degrees Celsius to grow and survive successfully. Their sex is also determined by the difference in temperature. Normally, female crocodiles hatch from eggs that hatch at a temperature of 28-31 আর C, and male crocodiles are hatched from eggs that hatch at a temperature of 32.5 সেল C. Female crocodiles reach puberty after about 8-10 years and then their length is up to 1.6-2 m. In the case of men, sexual maturity takes about 12-15 years.
The female crocodile protects her cubs and resists any attack. However, male crocodiles do not play any role in protecting the young.
They can live in the wild for about 26 years and in captivity for about 31 years. As they are 'pykilothermic' reptiles, they have to control their internal body temperature by sunbathing. They make holes in the edge of the pond so that the constant change in the surrounding temperature does not affect their body temperature.
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| Freshwater crocodile in water |
Freshwater crocodiles usually float on the surface of the water in such a way that only their beaks and eyes are visible. When they are on the surface of the water, they move depending on their eyes, nose and ears. And when they are under water, they receive sensations with the help of their skin. Even if there is a slight vibration in the water, they can understand then. Their skin is their only sensitive organ. It is so sensitive that it can predict the pH of water.
Freshwater crocodiles are opportunistic predators. That is, if you find something smaller than your shape in front of your eyes, you will immediately grab it and eat it. They don't even let their relatives eat them. They lie on the ground and jump on the prey. At times, they even catch bats or birds flying near the surface of the water. Crocodile cubs are usually eaten by small insects and frogs. As their body and age increase, so does the size of their prey. Crocodiles are usually able to eat about 10% -25% of their weight in one sitting.
Freshwater crocodiles play an important role in aquatic ecosystems. This is because they are at the highest level of the food chain in the reservoir and contribute to the control of the number of all other animals in the reservoir.
Freshwater crocodiles are killed for their precious skin. However, people kill them for more varied reasons. In addition to skin, they have ancient legends of making medicine from bones and fibers. Poachers also sell their eggs on the black market.
Freshwater crocodiles are now extinct in Bangladesh. At one time this crocodile was spread in innumerable canals and reservoirs including Padma, Meghna and Brahmaputra. However, at the government level, artificial breeding of freshwater crocodiles is carried out at the 'Karamjal Wildlife and Crocodile Breeding Center' in the Sundarbans.