|Langaha madagascarensis male|
|Langaha madagascarensis female|
|Left: Captive juvenile Langaha madagascarensis exhibiting hanging behavior; photo from Krysko 2003|
Right: Seed pods of the Ophiocolea floribunda, a Malagasy legume whose genus is Greek for 'hollow snake'
|Male (right) and female|
(left) L. madagascarensis
|Plate showing a male Langaha madagascarensis from Bonnaterre's 1790 Ophiologie|
From observations made on Langaha in captivity by Kenney Krysko of the Florida Museum of Natural Sciences, we know that Leaf-nosed Snakes lay eggs. When they hatch, the nasal appendages of juveniles are folded up so that their egg tooth can be used to break out of the egg. The appendage gains its normal shape after 36 hours. Juveniles exhibit the same vertical 'hanging' behavior as adults, which Krysko also suggests helps them mimic the seed pods of Malagasy plants (and perhaps deter predation, though by what predator is unclear).
|Hatchling Langaha madagascarensis, from Krysko 2003|
The other two species of Langaha are very poorly known. In Darren's TetZoo article, he states that only female Langaha alluaudi have nasal appendages, but I have been unable to find another source corroborating this fact, although I did find a photo on Flickr purported to be a male L. alluaudi (it looks similar to a male L. madagascarensis, also sometimes called L. nasuta, to me). Female L. alluaudi have longer, straighter nasal appendages than L. madagascarensis, and female L. pseudoalluaudi have shorter, more upturned ones (no word on what male L. pseudoalluaudi might look like). Why these differences? Perhaps differences in microhabitat or sexual preference are the cause. Who can say?
|Female (left) and male(?, right) Langaha alluaudi|
|Female L. pseudoalluaudi|
Although Madagascar is unique, it is similar to the rest of the world in at least one sad way: its natural places are disappearing quickly. Most of its forests have already been logged or converted to slash and burn agriculture, and what little remains is dwindling daily. If more effective conservation measures are not taken, including supporting the human communities that depend on the rich natural resources of this hottest of biodiversity hotspots, we may never find out what Langaha's nose is for.
|Male L. madagascarensis consuming Chalarodon madagascariensis|
Photo from Herp. Con. Bio. gallery for Tingle 2012
1 Three of these eight genera turned out not to be snakes at all: the limbless lizards Anguis and Amphisbaena, and the limbless amphibian Caecilia.↩
Thanks to Dick Bartlett, Jessica Tingle, David d'O, Bernard Dupont, Russell Speight, and G.E. Schatz for use of their photos.
Bonnaterre PJ (1790) Ophiologie, in Tableau encyclopédique et méthodique des trois règnes de la nature. Panconoke, Paris <link>
Krysko KL (2003) Reproduction in the Madagascar leaf-nosed snake, Langaha madagascariensis (Serpentes: Colubridae: Pseudoxyrhophiinae). African Journal of Herpetology 52:61-68 <link>
Krysko KL (2005) Feeding behaviour of the Madagascar leaf-nosed snake, Langaha madagascariensis (Serpentes: Colubridae: Pseudoxyrhophiinae), with an alternative hypothesis for its bizarre head structure. African Journal of Herpetology 54:195-200 <link>
Tingle JL (2012) Field observations on the behavioral ecology of the Madagascan Leaf-nosed Snake, Langaha madagascariensis. Herpetological Conservation and Biology 7:442-448 <link>