Sea snakes are mainly found in the tropical areas of the Pacific Ocean and the Indian Ocean. They live both near the coasts and in the open sea, but they prefer the first habitat, richer than their prey, the fish. In particular the coral formations, where there are many fish, are their favorite environment.
Unlike fish, sea snakes do not have gills, so they must periodically rise to the surface to breathe. Most species give birth to live offspring near the coast; the young are active immediately after birth. They have an extremely powerful venom, to which fish are particularly sensitive.
Their body demonstrates adaptation to the aquatic environment: the nostrils can be closed tightly, the head is elongated and wide like the neck to cut through the water, the tail is high and narrow like a fin. Due to their physical characteristics, they cannot move easily on land.
They are divided into true hydrophiinae and marine krait. True hydrophinae are ovoviviparous and appear to be descendants of some Australian elapids such as tiger snakes and death vipers. The marine krait, on the other hand, are oviparous and appear to be descendants of some Asian elapids.
Sea snakes and their toxicity
The study: Sea Snake Toxicity, gives interesting information on the toxicity of these animals. We can read: "Sea snakes, thought to the most abundant venomous reptiles on the planet, are found in the warm, tropical waters of the Indian and Pacific Oceans but not in the Atlantic Ocean.
There are 57 known species of sea snakes and two major subfamilies (Laticaudinae and Hydrophiinae). Sea snakes are not aggressive although they have been known to bite humans in self-defense or when surprised; this most commonly occurs when fisherman attempt to remove them from fishing nets.
Envenomation by sea snakes can be a potentially fatal condition, if not appropriately treated, as sea snake venom is a potent neurotoxin with low LD50 values. Subsequent respiratory compromise or drowning can occur owing to the paralysis of the diaphragm and skeletal muscles, respectively.
avoidance of sea snakes is the best approach." The study was led by: Justin Fuehrer, Erwin L. Kong, Heather M. Murphy-Lavoie.