Mod. 11: The Judgmental Shoelace is a Cryptic Species

With the recent and ongoing revolution of DNA sequencing technology, more and more species are able to be identified down to the genetic level. However, cryptic species have begun to reveal themselves through this readily available genetic information. Researchers, Pfenninger and Schwenk from Germany discovered that cryptic species are found in equal proportions across all major branches of the animal kingdom. This leads to the conclusion that there could be a multitude more species than we previously thought.

Just last year, for example, an article was published by researchers in India studying the genus Ahaetulla, a type of peninsular Indian vine snake. Yes, this is the judgemental shoelace snake. (Do not boop, or you will get the hurt juice).

When the first species of kind of vine snake, described by Linnaeus, was discovered, all the vine snakes in that region were thought to be part of a single species. However, as time drew on, the discovery of three additional species were added to the genus after 40 years (in 1827). In 2020 researchers from India worked to conduct extensive toxon sampling, whole genome sequencing, phylogenetic analysis, and species determination of their sampled vine snakes. Samples were taken from the Western Ghats, Sri Lanka, Laos, and central India, indicating a widely distributed range for the Ahaetulla included species. Following their study, five additional species in the genus (to only 6 previously) were discovered including A.sahyadrensis, A. malabarica, A. farnsworthi, A. borealis, and A. travancorica. As you can see from this phylogenetic analysis below, many of the snakes look very similar, so it is easy to see how they may have been mistaken for the same species before whole genome sequencing could have been done. Given that the number of known species in the Ahaetulla genus nearly doubled after this study really puts in perspective just how much we don't know about life on Earth and how many species are left undiscovered through their cryptic ways of blending in.


https://www.researchgate.net/publication/345358620_Disentangling_vines_a_study_of_morphological_crypsis_and_genetic_divergence_in_vine_snakes_Squamata_Colubridae_Ahaetulla_with_the_description_of_five_new_species_from_Peninsular_India