Let’s rewind to that sea snake we briefly mentioned last post. It was a black-banded sea krait, known in Okinawa as the Irabu, and in the rest of Japan as Erabu. The irabu are found mostly in the warm waters of the West Pacific, are air-breathing, surfacing every 6 hours, and are mostly nocturnal. Too slow to catch fish in a straight chase, irabu hunt in coral reefs, usually preying on other eels or lurking for passing by prey, paralyzing them with their extremely venomous bites (ten times stronger than a cobra’s!). While they normally hunt alone, sometimes they can also hunt in large parties alongside trevally and goatfish, with the snakes flushing out the prey from the reef and the fish feeding on fleeing fish. Not to worry for scuba divers or swimmers though, sea kraits would never attack humans unless in complete self-defence – they are typically considered docile while swimming.
Sea krait are ampibious: returning to land to digest their food, shed their skin, reproduce, and lay eggs. As adults they usually spend up to half their time on land. They exhibit ‘philopatry’, meaning, much like sea turtles, that they will return to the same beach time and time again. A research project in Fiji once moved a population of sea kraits away from their ‘home’ island to over 5km away, and within 31 days all had returned back to their original island beach. When on land irabu move at 1/5th the speed on land as they do underwater, with their tail shaped like a paddle to best equip them for swimming.
Despite its toxic properties, irabu is actually a common winter ingredient in southern Japan, where it is used along with boiled pig feet and seaweed to make Irabu soup, a miso and tuna like dish that is believed to help stimulate the central nervous system, and to help increase fertility. Unfortunately there isn’t any scientific research to back up this claim, and the fishing of the sea krait may be impacting their population numbers.
WARNING, if you don’t like seeing or are afraid of snakes, don’t watch either of the below videos!
For some footage both underwater and onland of these snakes, check out this BBC earth footage:
For more on the fishing of snakes: