The bay crocodile is a reptile belonging to the Crocodile family of Crocodiformes,[11]It is also called cannibal crocodile, estuarine crocodile, saltwater crocodile and Malay crocodile.[12]The trunk of the bay crocodile is long tube shaped;The snout is narrow and long, the front beak is low, the back of the snout is carved with obvious etched lines, and there is a bone ridge in front of each eye that tends to the snout end, but they are not connected with each other;There is no occipital scale at the back of the head, and there is no obvious difference between the neck and the head or the body. The scattered neck scales at the back of the neck form a square, with one slender bone scale on the left and one on the right;The tail is thick and flat, its length exceeds the sum of head and body, and its hind legs are longer;The abdomen is light white, and the back is dark olive or brown.[11]
The bay crocodile is distributed in South Asia, Southeast Asia and Australia. It likes to live on open coasts, river inlets and other places, but it also lives in swamps, rivers and other fresh water.[13]The bay crocodile is a large crocodile with a fierce temperament and a sense of territory.The larvae mainly prey on insects, amphibians, crustaceans, small reptiles and fish, and the adults mainly feed on mud crabs, turtles, lizards and water birds.The mating season of the bay crocodile is between May and June, depending on the region, and the rotten grass is used as the nest to lay 20-90 eggs each time.After 75 to 96 days, the baby alligator can be hatched.[14]
The bay crocodile is the largest reptile in the world.[11]As a large reptile, the bay crocodile also has great ornamental value and is one of the important resources to develop tourism.[15]
It was listed in the IUCN Red List of Endangered Species (ver 2.3 - LC) in 1996.[2]
In modern China, there has been a record of the distribution of the bay crocodile - The Sea Patrol.In 1907, Li Zhun sailed from Hainan Island to the Xisha Islands on two warships named Fubo and Chenhang for inspection.In his "Sea Patrol", crocodiles used to haunt southern China, probably living in mangroves.[3]
The bay crocodile is the largest of 23 crocodile species, and also the largest in the worldreptile。The adult body length of male bay crocodiles generally does not exceed 5 meters, and some can reach 7 meters.The maximum body length of female is 2.5-3 meters.Adult male alligatorweightUp to 600-1000 kg.The larva is light brown,bodyAnd the tail has black mottled stripes.The adult is dark in color, with pale yellow or white abdomen and gray tail at the bottom and end.Records show that the world's largest bay crocodile is 7 meters long.The alligator has 16-19 teeth on each side of the upper jaw and 14-15 teeth on each side of the lower jaw.As the bay crocodile is the only crocodile in the order Crocodiles without large scales on the back of the neck, it is also called "naked necked crocodile".[3]
The bay crocodile, like other crocodiles, also belongs to the dinosaur family.The appearance of the bay crocodile has not changed significantly since it appeared on the earth more than 200 million years ago.The snout of the bay crocodile is narrow and long, the back of the snout is clearly carved, and the front beak is low;The eyes are large, round and protruding,irisIt is green, with upper and lower eyelids and transparent blink membranes, as well as blink glands and lacrimal glands;There is a bone ridge in front of each other, but they are not connected with each other;The ear hole is located behind the eye and is as thin as a seam.There is only one external nostril opened at the snout end. There is no septum in the nasal passage, and there is alligator sail at the rear end without horizontal edge folds;When the mandibular dentition is bitten, it is interlaced with the maxillary dentition on the same vertical plane.
There is no obvious difference between the neck, head and body of the bay crocodile, and there are no occipital scales and occipital scales behind the head.The neck scales scattered on the back of the neck form a square, with one slender bone scale on each side.The dorsal scale has 16-17 rows, and the middle back has 6 rows of ribs.The body of the bay crocodile is a long tube, which is five times the length of its head.The tail of the bay crocodile is thick, flat, and longer than the sum of the head and body. It can be used as a powerful weapon when attacking.
Bay alligatorlimbIt is thick, the scales on the back edge of the limb form a saw edge, the hind limb is long, with five toes, the fifth toe is short, the toe base is webbed, the inner two toes are half webbed, the three toes have claws, and the outer toes are full webbed.The back of the adult bay crocodile is brown or dark olive, and the belly is light white;The larva has light and bright snout color, light body or background color, and dark red spots;Or the background color is deep with light spots.[4]
Habitat environment
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Bay crocodiles live in the bay or cross the sea.[5]Bay crocodiles live in accordance with water. They put their homes in mud nests near lakes or rivers.In addition, male bay alligators will also carefully select a territory for themselves. The factors to consider include not only food supply, places to bask in the sun, but also whether there is a convenient path to the opposite sex.[6]
Life habits
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Bay crocodile is a large crocodile with fierce personality.Have a sense of territory.The endurance is also very outstanding. It can swim from Australia through more than 1000 kilometers of ocean to the Bay of Bengal.It has a physiological structure suitable for high salinity water.Bay crocodiles are at the highest level of the wetland food chain, and some areas are even more terrible than tigers.The larvae mainly prey on insects, amphibians, crustaceans, small reptiles and fish, and adults will prey on larger animals, but they mainly feed on mud crabs, turtles, lizards and water birds. Some larger adults will even prey on buffalo, livestock, wild boar and monkeys, and will also prey on sharks in the sea.In Australia, the bay crocodile has also been recorded as cannibal, even attacking ships, so it is also called "cannibal crocodile".[3-4]
Bay crocodiles have a strong sense of territory. Male crocodiles dominate the territory, expel intruders, and one male leads the herd of females.Adult crocodiles are often underwater, with one eye and nose above the water.Ears and eyes are alert, and when frightened, they immediately sink.In the afternoon, they often float in the water to bask in the sun. At night, their eyes are as bright as torches, and their young crocodiles are glowing with red light.[3]
The ferocious appearance of the bay crocodile makes it a "cold-blooded killer" in people's eyes.The most lethal weapon of the "killer" is its blood basin and mouth.This big mouth, which accounts for one sixth of the length of the alligator, has great bite force, about 200 kg per square centimeter, more than 10 times stronger than human bite force.However, the Bay Crocodile's teeth cannot bite and chew food. It often clamps its prey with its big mouth and drags them to the rocks or tree trunks on the water bank to smash them violently until they are broken or softened and eaten a little more.Because the bay crocodile's teeth can't chew food, it has a special stomach, which contains the strongest stomach acid of vertebrates.This makes its digestive function very good, and it can digest any food, including bones.Bay crocodiles sometimes eat sand and stones to help themselves digest.[6]
Distribution range
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Distribution:Australia, Bangladesh, Brunei Darussalam, Cambodia, India, Indonesia, Malaysia, Myanmar, Palau Islands, Papua New Guinea, Philippines, Solomon Islands, Sri Lanka, Vanuatu, Vietnam.[2]
Extinction:Singapore.[2]
Possible extinction:Thailand.[2]
Distribution map of bay crocodile
Reproductive mode
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Females reach sexual maturity at about 10-12 years old.Males do not reach sexual maturity until they are 16 years old.[6]The mating season of the bay crocodile is between May and June, depending on the region: Thai varieties lay eggs in July and August, and Java varieties can even see crocodile eggs in February.Male bay crocodiles often fight for territory during the breeding season. They will first pose for battle, and then head against each other violently.If this tactic doesn't work, they will bite each other with their mouths until they break the opponent's chin.Of course, the winner will win the right to mate with a female.The male presses his body on the female's back, grabs the female alligator with his forelimbs, wraps his tail around the female's posterior segment, and mates for several hours.[3][7]
The bay crocodile makes use of decaying grass to nest in the shady hills near the Danshui River (more than 60000 meters from the sea), sweeps out a 7-8 meter platform with its tail. On the platform, there are nests with a diameter of 3 meters for laying crocodile eggs. The nests are about 4 meters away from the river and are composed of leaves. Each nest has about 20-90 white calcium shell eggs with a diameter of 80 mm × 55 mm.During the incubation period of eggs, the female alligator will always stay near the nest and sprinkle water on the eggs with her tail from time to time to maintain the temperature of eggs. The temperature will be 30-33 ℃ and the eggs will hatch for 75-90 days.The hatchlings are 240 mm long, 480 mm in one year, 1156 mm in three years, and 5.2 kg in weight.[4-5]
The wild alligator is protected in most countries, but the effectiveness of protection in some countries is questionable.It is internationally recognized that Papua New Guinea and Australia are the best protected countries, where the wild populations are in a state of sustainable use and growth.A conservation management plan similar to the two countries mentioned above is being tested and implemented in Indonesia.In addition, the number of artificial bay crocodiles is rising significantly, especially in Southeast Asian countries.[9]
Key values
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The largest bay crocodileeconomic valueIt is one of the precious leathers in the world.[10]The meat of the bay crocodile is edible, and the Burmese love crocodile meat.Thai people do not love crocodile meat but cherish crocodile gall as a cure for women's infertility.The bay crocodile has a wide distribution area and a large output. In addition to eating meat, the Nanyang people also tanned crocodile skins to make shoes, belts, suitcases, handbags, etc. The patterns and colors are beautiful, and they are exquisite and expensive decorative leather products with high technological value.As a large reptile, the bay crocodile also has great ornamental value and is one of the important resources to develop tourism.[5]
Defensive strategy
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If you are attacked in the water, poke it in the eyes when it is in chaos;If on land, look for an opportunity to punch a few punches on its nose, it will run away. This is because the crocodile has a well-developed nose nerve. Once it is hit, it will make the crocodile weak;If you are bitten, you'd better turn with it, and then seek the opportunity to break away.However, the bite force of the bay crocodile is about 1902 kg, which is difficult to break away.[3]
world record
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The world's largest reptile:The bay crocodile is the largest of 23 crocodile species and the largest reptile in the world, with a maximum length of more than 7 meters and a weight of 1400-1600 kg.(Guinness World Records)
