The saltwater crocodile (Crocodylus porosus) is a reptile native to brackish wetlands and saltwater habitats from Southeast Asia across India’s east coast, Micronesia, and northern Australia to the Sundaic region.
The species has been listed among the IUCN Red List as Least Concern since 1996.
It is a dangerous animal, so people are advised not to share the same environment with them.
The largest living crocodilian and reptile known to science is the saltwater crocodile.
 Males grow up to a length of 20 ft (6 m), rarely exceeding 21 ft (6.3 m) or weight of 1,000 to 1,300 kg (2,200 to 2,900 lb).
On the other hand, females are much smaller and rarely reach 10 ft (3 m).
The saltwater crocodile is known by some other names, which include Indo-Pacific crocodile, sea crocodile (also called saltie), estuarine crocodile, and marine crocodile.
Scientific Classification
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Reptilia |
| Order | Crocodilia |
| Family | Crocodylidae |
| Genus | Crocodylus |
| Species | Crocodylus porosus |
Evolution
Some saltwater crocodile fossil remains were dated to the Pliocene era and excavated in northern Queensland. One of the oldest Crocodylus fossils to be recorded was dated in the Late Miocene.
The saltwater crocodile is a sister taxon of the Siamese and the Nile crocodile. Phylogenetic research gave the analyses that indicate that Crocodylus metamorphosed in the Oligocene Indo-Pacific about 19.3 to 25.5 million years ago.
As a result of the warm and wet climate, the dispersal of crocodiles from Australasia (comprising Australia, New Zealand, and some other close regions) to Africa may be facilitated.
The genetic lineage comprising Nile, Siamese, and saltwater crocodiles is estimated to have diverged 6.52 to 10.60 million years ago. While Siamese and Nile crocodiles plausibly diverged from the group 4.19 to 7.94 million years ago.
Appearance
When comparing snout, the saltwater crocodile has a wider snout than most crocodiles and an even longer snout when compared to the mugger crocodile (C. palustris). The width of the snout at the base is half its length.
A pair of ridges can be found in the eyes and runs along the center of the snout. The shape of its scales is oval, and the scutes are either absent or very small compared to other species. A gap is present between the dorsal and cervical shields.
In addition, the saltwater crocodile has a useful asset: its relative lack of scutes. This asset helps distinguish a saltwater crocodile in illicit leather trading or captivity.
It also comes in handy when differentiating young or sub-adult saltwater crocodiles from other crocodiles. It also has fewer armor plates on its neck than other crocodiles.
The broad body of an adult saltwater crocodile differs from that of other lean-body crocodiles. This leads to the early assumption that the reptile was an alligator, though it is unverified.
Young saltwater crocodile’s coloration is pale yellow with black spots and stripes, expressed on their bodies and tail. This coloration changes when the crocodile reaches adulthood. In comparison, adults display a darker greenish-drear, with a few light grey or tan areas.
Some color variations have been recorded, whereby some adults retain their young, fairly pale skins, but others become so dark that they appear blackish. The ventral surface is yellow and white, irrespective of age or size.
Stripes are on the lower sides of their bodies except for the belly. In addition, saltwater crocodiles’ grey tails have dark bands around them.
Size
The weight of a crocodile is measured cubically, where the square-cube law states that the weight increases approximately as the length increases.
Male
The typical range of an adult male saltwater crocodile (both young and old) is between 11 ft 6 in – 19 ft 8 in (3.5 – 6 m) in length and weighs about 400 – 2,200 lb (200 – 1,000 kg). The average adult male ranges from 14 ft 1 in – 16 ft 1 in (4.3 – 4.9 m) in length and weighs about 899 – 1,151 lb (408 – 522 kg).
Female
The typical range of an adult female saltwater crocodile (both young and old) is between 8 ft 10 in – 10 ft 2 in (2.7 – 3.1 m) in total length and weighs about 168 – 227 lb (76 – 103 kg).
The average large mature female measures up to 11 ft 2 in (3.4 m) and weighs about 260 – 440 lb (120 – 200 kg). The largest known female saltwater crocodile was measured at 14 ft 1 in (4.3 m) in length.
Habitat
The saltwater crocodile inhabits river deltas and coastal brackish mangrove swamps from India’s east coast, Sri Lanka, and Bangladesh to Myanmar, Thailand, and Malaysia. They can also be found in Vietnam, Cambodia, Brunei Darussalam, Philippines, Indonesia, Solomon Islands, Vanuatu, Palau, and Australia’s north coast.
Diet
Saltwater crocodiles are not meticulous in their food choices and are ready to prey on any animal. They can survive with very little food for a long time. The saltwater crocodile is an apex predator, given that it is a large and opportunistic hypercarnivore.
It hunts mostly by ambush before it swallows its prey whole. Â When in its most favored habitat, it prevails over any animals that wander into its territory. The saltwater crocodile commonly catches and drowns its prey before tearing and swallowing.
 Some of the animals it preys on are apex predators, such as saltwater and freshwater fish, sharks, crustaceans, mammals (humans), birds, and various reptiles.
Reproduction
A male crocodile around 10 ft 10 in (3.3 m) reaches full sexual maturity at 16 years, while a female around 6 ft 11 in (2.1 m) reaches full maturity at 12 to 14.
Saltwater crocodiles mate in the wet season when the water levels are high. Courtship occurs in September and October, and the eggs will be laid by the female between November and March.
