FORT > Resources > Education > BTS Home Page > Biology of BTS > Other South Pacific Snakes
Other Snakes of the South Pacific Most Likely to be Encountered
Sea Snakes
The exceptions to the "it's-safe-to-handle-them" rule are sea snakes that could be encountered frequently in Palau and other western Pacific locales and infrequently in most Central Pacific Islands. While some sea snakes are reluctant to bite even when provoked, they should still be considered venomous. The Australian and Southeast Asian regions are centers of diversity for sea snakes, and abnormal dispersals could result in any of several other species of sea snakes appearing in the shallow waters or shorelines of Central Pacific Islands. A major distinguishing trait for sea snakes is their clearly defined paddle-shaped tail that they use to propel their body through the water when swimming. Other snakes have relatively pointed tapering tails, very unlike this flattened, paddle-like structure. All sea snakes should be identifiable on this basis. In addition, most sea snakes have relatively small heads relative to their overall body girth and length. All sea snakes have some toxic venom and should be considered venomous by the non-expert.
Two species of sea snakes are most likely to be encountered in the Central Pacific Region. Although new distributional records for sea snakes may be of interest to scientists, sea snakes pose no real threat as invasive species and under most conditions should be left in the habitats in which they are sighted. Sea snakes rarely bite in defense even when contacted by divers swimming intimately with them in their environment.
The Yellow-lipped sea snake, Laticauda colubrina
This snake has a prominent paddle-like tail. The conspicuous grayish-white body coloration with prominent dark transverse bands or blotches is markedly different from the coloration of the Pelagic sea snake. This coloration could be confused with other sea snakes (similar in appearance) resident in the Australian and Southeast Asian regions, but it is less likely to be encountered in the Central Pacific. This snake is common in the Republic of Palau and also infrequently encountered in Micronesia; however, it is poorly documented east of Palau. Laticauda may be found in extremely shallow shoreline and reef conditions. As a member of the family Laticaudidae, it is one of the few sea snakes known to haul out on land for purposes of egg-laying or in sea caves and isolated rock islands where aggregations of unknown significance are reported. It is technically a venomous species but rarely bites defensively. Human envenomations are rare or nonexistent. Its venom is only used in feeding to immobilize fish and other animals on which it feeds. However, to be safe, individuals of Laticauda should not be handled casually by inexperienced persons. One or more harmless banded eels have the elongated body form, paddle-like tail and coloration of the yellow-lipped sea snake and hence can be confused with this species.
The Pelagic sea snake (or yellow-bellied sea snake), Pelamis platurus: This snake has a prominent paddle-like tail. The Pelagic sea snake's coloration normally includes a black background color contrasting strongly with a yellow belly and pale yellow lateral stripe along the body which frequently breaks into an undulating array of black and yellow blotches on the posterior body and tail. This snake spends much of its time floating in open ocean waters along the edges of the continental shelves of large land masses. It is venomous, although not nearly as toxic as many other sea snakes. Fatalities are rare even among fishermen who, bare-handed, regularly remove these snakes from their nets. It is rarely seen in the Central Pacific but is always a possibility as an ocean vagrant dispersed as a result of unusual currents and storms. It is a member of the largest sea snake family, Hydrophiidae, and hence bears its young alive without leaving the ocean.
Top of Page
Snakes Living on Land or in Fresh or Brackish Water
Common Treesnakes, Genus Dendrelaphis spp.
These snakes have a number of characteristics that aid in identification and comparison with other snakes likely to be found in the region. These include a slender body, relatively large head and eyes, alert behavior, defensive strategy of inflating the neck and anterior body vertically when excited, exposing a lighter skin coloration between the scales that may include blue or black spots, and unicolor olive green to dark blue/black coloration with or without a conspicuous dorsal stripe. These harmless racer-like snakes are encountered on the ground or in vegetation when active in daylight hours, or on low vegetation when sleeping at night. Dendrelaphis species are native to a broad area spanning Australia, New Guinea, the Philippines, and approaching the Central Pacific Region as far east as Palau. A green-colored species of the genus was captured in Saipan several years ago and was thought to have arrived as a stowaway in construction materials arriving from the Philippines. This beautiful snake is a predator of lizards and frogs and poses no threat to man. It should be protected from being killed within its native range.
Dog-faced water snake, Cerberus rynchops
Relative to other snakes, dog-faced water snakes have a blunt head, rounded snout, and relatively small eyes positioned close to the top of the head. The coloration is dark to medium brown with faint indications of darker blotches on the dorsal body. Some yellow may be present along the ventrolateral margin of the body adjacent to the gray to yellowish ventral coloration marked with alternating blotches of dark and light color. The overall body form is one of a relatively heavy bodied snake (i.e., body girth robust relative to body and tail length). These harmless water snakes are commonly found in tidal creeks, mangrove swamps, and in or near bodies of freshwater. Cerberus species are native to Palau and many areas west of Palau, including the Philippines and Southeast Asia. Although these snakes are capable of being pugnacious and biting when handled, they are non-venomous fish eaters constituting natural parts of the aquatic ecosystems in which they occur and should not be killed indiscriminately.
Pacific Island Boa, Candoia carinata
These boas are relatively small with a head moderately set off from the more slender neck region, relatively short prehensile tails, and variable coloration ranging from light gray-brown to orangish rusty brown with or without distinct dorsal blotches, and a white venter. The shape of the head is distinctive relative to other snakes, with a relatively long, narrow snout and overall delicate appearance. Males have a pair of tiny spike-like spurs anterior to the anal region that are vestiges of the limb apparatus largely lost in the evolution to limblessness. Candoia carinata is native to some islands in the Republic of Palau, and a second species of the genus occurs in New Guinea, the Solomon Islands, and as far east as some islands in American and Western Samoa. They are absent from the eastern Carolines and Mariana Island groups. As members of the Family Boidae, Candoia are protected under the Convention for International Trade in Endangered Species and by most local governments. This species is also harmless and should be protected in its natural habitat.
Habu snakes, Genus Trimeresurus
Like most vipers, Habu snakes have an enlarged and angular head, markedly set off from the narrower neck, a relatively heavy body and short tail relative to the brown Treesnake, and enlarged front fangs that are erected when biting but fold horizontally when the mouth is closed. These snakes are true vipers native to the Southeast Asian Region and larger island groups including the Philippines, Ryukyus, Japan, etc. They are all venomous, and the bite of many species can be fatal. They should be treated with considerable caution if encountered in areas outside their range as well as where they occur naturally. Medical attention should be sought promptly in the event of a bite in which venom is likely to have been injected.
Garter snakes, Thamnophis sp.
These snakes are moderately sized with a light mid-dorsal stripe and lateral stripes along the ventrolateral margin of the greeenish to olive brown body. Some individuals may have conspicuous zones of red coloration on the dorsal body. The dorsal scales are keeled with a raised ridge running longitudinal along the length of each scale. This harmless species and other similar species of the genus Thamnophis are most likely to appear on Pacific Islands as a stowaways in bundled Christmas trees originating from the Western United States.
The Blind snakes, Ramphotyphlops sp.
These tiny worm-like snakes have extremely reduced eyes evident only as tiny dots on the top of its head. The head is not set off from the body, and the short blunt snout must be carefully examined to distinguish it from the stub tail, which has a tiny spur-like scale on the tip. Most animals have a body girth comparable to that of a pencil lead, and the
species rarely exceeds a few inches in length (maximum is about 1 foot). The color is often dull black or slate gray, but some individuals can be pinkish gray.
R. braminus is an inconspicuous snake known from many oceanic islands (e.g., throughout the Marianas, Carolines, and Hawaiian Islands, as well as many other areas of the tropics). It is an all-female species (i.e., the females lay eggs without benefit of mating with males), and thus every female could potentially found a new population. These snakes are commonly encountered in soil and litter and have colonized many oceanic islands when moved in the loose soil associated with potted plants. Other blind snakes might be encountered, but it will be difficult for anyone but a snake specialist to distinguish between these species. This harmless species and its relatives are predators of termites and ants, and are not considered to be threats to island ecosystems even as introduced species. In fact, other species similar in size, body form, and habit do exist on Pacific Islands (e.g., two species exist on some islands in Palau, but the distinctions between the various blind snakes are subtle and beyond the scope of this discussion).
Western Gopher or Bullsnake, Pituophis melanoleucus
This harmless snake differs markedly from most snakes mentioned above, in that it has a yellowish tan dorsal coloration with conspicuous square markings along its body that may be present in a variety of colors including rust, dark brown, or black. It also has secondary smaller blotches lower on the body's side. Its scales are keeled and arranged in 27-37 longitudinal rows when counted at midbody. It is most likely to be confused with a viper, which has similar color patterns, but can be distinguished by its more pointed head, round pupil of the eye instead of elliptical, and a vertical line through the eye as opposed to horizontal. As a common snake in the western continental United States, this species has occasionally arrived to Pacific Islands (e.g., Saipan and Pohnpei) as a stowaway in cargo or as a child's pet. Mimicking more dangerous species, it attempts to intimidate animals that threaten it by producing a hissing sound, vibrating its tail, and flattening its head, which has oftentimes led to its unfortunate death at the hands of people, fooled by the bluff, who confuse it with a rattlesnake.
Biology
of the BTS & Pacific Snakes
Impacts
& Damages from the BTS
Control
& Containment of the BTS
Report Snake Sightings!
Search FORT