hi, i'm jonathan bird andwelcome to my world! ( ♪ music ) the sea snake is an animalsurrounded in mystery—known forits incredibly powerful venom,but not much else. just how dangerousare these marine reptiles? i have traveled to queensland,australia on a quest to learnabout sea snakes.
is there anything to keep snakes away, here on australia's greatbarrier reef, sea snakes arefairly common. lets go see if we can find one. i hit the water, grab my cameraand head towards the sea floor. today i'm diving on a littleseamount called a coral bommie.it's a mini-mountain of
coral sticking up from thebottom, but not quite reachingthe surface. near the top of the bommie,thousands of small fish feed onplankton passing by in thecurrent, but they stay close to thereef, because they are beingwatched by a big school of jacks who are on the prowl for foodthemselves. the bommie is covered inhealthy coral that provideslots of nooks and crannies forthe fish to hide if they need cover. on the other side of thebommie, a large school ofsnappers are also looking forsomething to eat, and keeping a safedistance from the jacks. as i swim along at the base ofthe bommie, i'm keeping my eyesopen for a snake-like
animal. the coral looks healthyand a spinecheek anemonefishgives me a quick glance from the safety of her host anemone. but i keep scanning the bottomand at last i have found myquarry: an olive sea snake, the most common species aroundthe great barrier reef. it'sswimming along the bottom doing the same thing everything elseis doing—looking for food. thesea snake is closely related to a land snake, except it hasadapted for life underwater. when a sea snake flicks itstongue, it's getting rid ofexcess salt secreted by special glands in its mouth. sea snakeslive exclusively in the ocean,but since they're reptiles, their kidneys can't deal withtoo much excess salt in theirblood.
a sea snake gets around with aflattened section of tail thatlooks like an oar and serves as a fin. it looks just like aneel when it swims, undulatingits body and getting propulsion from that flattened tail. although sea snakes prefer toeat fish, eels and shrimp,these snappers aren't at all afraid of the sea snake,because they are way too bigfor the sea snake to bite. this snake is heading for thesurface to grab a breath ofair. a sea snake, just like a land snake, has lungs and mustbreathe air to survive. it canhold its breath up to 3 hours during a dive. recentresearch has shown that somesea snakes also can absorb alittle bit of oxygen directly from thewater through their skin, whichis probably why a breath
can last so long. after spending a minute at thesurface breathing, the seasnake comes back down to thebottom. it's poking around, looking forholes where it might corner afish or shrimp. it sticks its head into the holes, hopingto get lucky. the sea snake is most closelyrelated to the cobra on land,and its venom is quite similar to cobra venom, butconsiderably more potent. if itmanages to grab a fish, thevenom will kill it in seconds. sea snakes quite often take arest on the bottom, sleeping asthey hold their breath. i use the opportunity to sneakup on one. in spite of theirfearsome venom, sea snakes
are very timid and notparticularly aggressive.although this one is obviouslynot thrilled about being picked up, itdoesn't try to bite me. and when i let go, it justswims away. away. i find another one and can'tresist the opportunity to showthe flattened tail section. swim, be free! although the sea snake is oneof the most venomous animals inthe world, you're not verylikely to be bitten by one. there are 62 known species ofsea snakes and they live allaround the tropicalindo-pacific.
i found this banded sea snakein the philippines. they likenice warm tropical water because
they are cold-blooded, like allreptiles. if the water gets toocold, they get lethargic. so, no matter what you mightthink of snakes, sea snakes aretimid and shy animals that represent almost no threat atall to people, even though theyproduce some of the most powerful venom in the world.
