Elapidae Family of Sea Snakes

One Sea Snake of the Elapidae Family can be found in this website:

Yellow-bellied Sea Snake, Hydrophis platurus. A representative of the Elapidae Family of Sea Snakes.

Phylogeny: Sea Snakes of the Elapidae Family have a spinal cord and a bony spine, placing them in the phylum Chordata and the subphylum Vertebrata. They are in the infraphylum Gnathostomata, the megaclass Tetrapoda, the superclass Reptilia, the order Squamata, the suborder Serpentes, and the infraorder Alethinophidia. Very familiar snakes such as adders, cobras, coral snakes and mambas are included in the Elapidae Family. There are sixty genera in this family and around three hundred ninety species. Sea snakes are divided into two sub-families – Hydrophiinae or True Sea Snakes, and Laticaudinae or Amphioxus Sea Snakes. Amphioxus Sea Snakes, or Sea Kraits, are more primitive and to come ashore to mate. True Sea Snakes spend their entire lives at sea. Depending on the source, there are sixty to seventy four species of sea snakes in the Elapidae Family. The name Elapidae comes from the Greek words meaning “sea serpent” or “sea fish”, even though many species are terrestrial. Species in this family are commonly called Elapids.

Morphology: Elapid Sea Snakes, like all snakes, are elongated and legless. They are  characterized by having short, fixed, fangs in the front of the upper jaw, which distinguishes them from venomous pit-viper snakes that have long, folding, fangs. These fangs may be weak and break easily, but these animals offset this weakness by being very venomous. Sea Snakes have vertically flattened tails, valve-like flaps covering their nostrils, and skin that allows for the exchange of gases while underwater. They have lungs and are air breathers but because of these adaptations, some species can stay submerged for up to eight hours. Sea Snakes reach a maximum of 2 m (6 feet 6 inches) in length.

Distribution: Elapid Sea Snakes are generally found in open water or hunting within reef structures. Sea Snakes spend the majority of their lives in shallow water, but can be found at depths up to 100 m (328 feet). As air breathers, they need to spend time at the surface. They are found in tropical and subtropical waters of the Indian and Pacific Oceans with the great majority being found in the Indian Ocean and Western Pacific Ocean. Only the Yellow-bellied Sea Snake is found in Mexican waters.

Reproduction: Elapid Sea Snakes are gonochoric (either male or female for life).  Reproduction is sexual, with internal fertilization. True Sea Snakes (Hydrophiinae) mate and give birth in the water. They are oviviparous (The eggs hatch within the female and are born live). Sea Kraits (Laticaudinae) are oviparous (egg laying) and come ashore to mate and lay eggs in moist crevasses. Once these eggs hatch the young snakes quickly make their way to the water.

Ecosystem Roles: Elapid Sea Snakes are carnivorous feeding primarily on fish and fish eggs. In turn they are preyed upon by sea birds, large fish, and sharks. Some species of sea snakes have light sensing skin on their tails to help protect these important tails from predation.

Caution! All Sea Snakes are venomous. Their initial bite is not particularly painful, and it may appear as pinpricks. Within a few hours of envenomation dizziness, muscle pain, muscle spasms, paralysis and vomiting may occur. Within  three  to six hours the involved muscle fibers will break down and release their contents into the blood stream, often leading to reduced kidney function. Approximately 3% of Sea Snake bites are fatal and such bites should be taken seriously.