Okinawa habu, Kume Shima habu
Protobothrops flavoviridis is a species of venomous pit viper endemic to the Ryukyu Islands of Japan. No subspecies are currently recognized. Local common names include habu, Okinawa habu, and Kume Shima habu.
The Habu is a species of venomous pit viper native to Japan. It is slenderly built and gracefully proportioned with a large head. The crown of the head is covered with small scales. The Habu has a light olive or brown ground color, overlaid with elongated dark green or brownish blotches. The blotches have yellow edges, sometimes contain yellow spots, and frequently fuse to produce wavy stripes. The belly is whitish with dark coloring along the edges.
Habu snakes are found on the Japanese Ryukyu Islands, including Okinawa and the Amami Islands. They inhabit forests, grasslands, shrubland, coasts, and cultivated fields. They may also be found on rock walls, in old tombs and caves, and in urban areas.
Habu snakes are solitary, terrestrial, and mostly nocturnal creatures. They often enter homes and other structures in search of rats and mice. Bold and irritable, these aggressive snakes can strike quickly and have a long reach. Their venom is highly toxic. A bite from a Habu snake can cause nausea, vomiting, hypotension, and possibly death. If a bite victim receives medical care promptly, bites are not life-threatening.
The incidence of snakebite in the Amami Islands is 2 per 1,000 people, which is considered very high. The venom of this species is of high toxicity, containing cytotoxin and haemorrhagin components, yet the fatality rate is less than 1%. A bite from a habu snake can cause nausea, vomiting, hypotension, and possibly death. There have been cases where victims report the loss of motor function in hands and legs following treatment. If a bite victim receives medical care promptly, bites are not life-threatening. However, 6-8% do suffer permanent disability.
LD50 values of 3.1, 4.3, 3.7, 2.7, 3.7, 3.8 mg/kg IV, 5.1 mg/kg IP and 6.0, 3.5-5.0, 4.5 mg/kg SC have been reported for the venom.
Habus snakes are carnivores. Their diet includes small mammals, snakes, frogs, and birds.
Habu snakes are oviparous and lay eggs. The breed in early spring and in mid-summer females lay up to 18 eggs. The hatchlings, which emerge after an incubation period of 5-6 weeks, are 25 centimeters (10 in) in length and look the same as the adults.
The main threats to the Habu include exploitation and persecution by humans. On the island of Okinawa, these snakes are heavily collected, primarily for use in habushu (liqueur), alleged to have medicinal properties.
The IUCN Red List and other sources don’t provide the number of the Habu total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.