The ornate reef sea snake is active by day and night (3), and is known to adopt a generalist feeding strategy (15), eating a wide variety of fish (1) (3) (4) (15). It tends to feed on free-swimming fish that are found in habitats close to coral reefs, such as sandy areas, but is also known to feed on benthic and demersal species, including fish from the Apogonidae, Nemipteridae and Mullidae families. In addition, the ornate reef sea snake has been recorded eating fish discarded from prawn trawl fisheries (7).
Despite being an air-breathing animal, the ornate reef sea snake is capable of remaining underwater for up to two hours at a time, before surfacing to breathe again. Its single, elongated lung, which extends for almost the entire length of its body, is highly efficient for gas exchange, and sea snakes are also able to absorb oxygen through their skin when underwater. As in other sea snake species, the ornate reef sea snake has specialised valves which block off the nostrils while underwater (7).
Living in the marine environment poses several other challenges, and like other sea snake species, the ornate reef sea snake has a specialised gland under its tongue which enables it to excrete excess salt from its body. A sea snake sheds its skin approximately once every two to six weeks. By shedding its skin so frequently, a sea snake can get rid of the many marine species, such as algae and barnacles, which become attached to it (7).
Mating in sea snakes is a lengthy affair, and the male is unable to disengage from the female until copulation is complete. Like most species of sea snake, the ornate reef sea snake is viviparous, meaning that it gives birth to live young rather than laying eggs (7). In northern Australia, the gestation period for this species is around six to seven months, with births occurring in September (7), while off the east coast of India and around Thailand, gravid females have been found between March and April (3).
Although litter sizes in this species vary from 1 to 17 young (3), the ornate reef sea snake generally produces small clutches of relatively large offspring (1). This species is reported to commonly produce between two and five young at a time (1), although in northern Australia the average number of young per litter is six (3) (7). It is thought that female ornate reef sea snakes reproduce every year (7).