Heller’s Red-necked Keelback

The Heller’s Red-necked Keelback (Rhabdophis subminiatus) is a colorful semi-venomous snake belonging to the family Colubridae. It is widely distributed across South and Southeast Asia and has also been recorded in Bangladesh, especially in moist forest regions, wetlands, hill tracts, and areas near streams or ponds. This species is well known for its striking appearance, particularly the bright red, orange, or reddish-yellow coloration behind the neck, which acts as a warning signal to predators. The body is usually olive green, brownish, or dark green with strongly keeled scales and a lighter underside. Juveniles are often more vividly colored than adults.

Unlike cobras or vipers, the Red-necked Keelback is a rear-fanged snake. It possesses enlarged teeth at the back of the upper jaw that help deliver venom during prolonged bites. In addition to its venom

system, this snake has a unique defensive adaptation called nuchal glands located behind the neck. These glands store toxins obtained from poisonous toads that the snake consumes as part of its diet. When threatened, the snake may flatten its neck, expose the bright red coloration, and release toxic secretions as a defense mechanism. This combination of venom and chemical defense makes the species medically significant, although it was once commonly mistaken as harmless.