Valentine’s Day in 2025 is a special one: we introduce an Anilovely new species from the Tsingy de Bemaraha karst of western Madagascar: Anilany karsticola. The species description is published open access in the 14 February issue of the journal Salamandra, and you can read it here!
In 2006, a team consisting of Frank Glaw, Jörn Köhler, Parfait Bora, and Hildegard Enting undertook an expedition to the Tsingy de Bemaraha, a bizarre limestone karst area in western Madagascar with a very high level of endemism for all manner of organisms. One of the curiosities they collected on that trip was a little microhylid frog, which resembled another species from hundreds of kilometres away in the central highlands of Madagascar, which at that time was called Stumpffia helenae. Like that species, this one had broad finger discs, but only on two of its four fingers. This sets both of these species apart from all other Stumpffia, and indeed all other related frogs from Madagascar.
Later, genetic work by Katharina Wollenberg Valero and colleagues in 2008 showed that these two lineages, from the central highlands and the western Tsingy, were closely related, and that they are actually quite distantly related to Stumpffia. My colleagues and I gave the new name Anilany to this clade in 2016, in order to settle a taxonomic debate that was going on about the definitions of the genera Stumpffia and Rhomobphryne, which centred around the relationships of ‘S.’ helenae. By moving it to Anilany helenae, stability was restored. But there remained this curious, closely related lineage from the Tsingy de Bemaraha, which had inherited the temporary name ‘Anilany sp. Ca14′.
Anilany helenae itself is considered a Critically Endangered species, and is listed among other such species on the EDGE list. Until recently it was only known from the Ambohitantely Special Reserve, a tiny patch of forest in the highlands, surrounded by a barren landscape of grasslands. This area is constantly under threat by fire, and recent fires have reduced its size substantially. Not long ago, Katherine Mullin and her team discovered a second location for the species in another tiny fragment, but the overall conservation prospect was not really changed by this.
As time went on, I started to come across other curious records of frogs that looked like Anilany from across Madagascar, that had been uploaded to iNaturalist. These ranged over quite a large area, much of which was distantly separated from both the Bemaraha population, and the Ambohitantely Anilany helenae. New specimens collected by Frank Glaw and David Prötzel near Mahajanga were also clearly members of this group. But were these new species, or a massive range extension of A. helenae? If so, they would completely change up our view of its conservation status and ecology. So, we set to work to understand this better.
The results of this work were quite surprising. Despite the enormous distances involved, there is relatively little genetic differentiation among Anilany populations, in some cases below the thresholds we usually use for the recognition of putatively species-level lineages in these frogs. They are also surprisingly morphologically similar, and despite us including osteology from several micro-CT scans in our work, consistent patterns were hard to identify. This had us really scratching our heads, and first author Alice Petzold and I repeatedly had meetings where we tried to puzzle over the picture, to try to figure out what the best taxonomic solution would be.
In the end, it became clear that the population from the Tsingy de Bemaraha really is a distinct species, which we have named Anilany karsticola in reference to the karsts in which it dwells. But the popualtion from Mahajanga, as well as those found across the northwestern coast of Madagascar, remain quite curious. How could such a small frog, which also almost certainly breeds in terrestrial nests, have managed to cover so much distance, most of which is unsuitable habitat, and moreover live under such different conditions as the coastal and highland forests? After all, very few members of the similarly miniaturised genus Stumpffia occur over more than a few dozen kilometres distance, let alone hundreds of kilometres—micro-endemism is generally thought to be the rule in this Madagascar-endemic subfamily of microhylid frogs. And what does this mean for the conservation of Anilany helenae? Should we still consider it Critically Endangered when it might occur over such a large area?
Our conclusion in the end is that the picture is simply insufficiently clear to really draw firm conclusions on what this means for the conservation of A. helenae, or the possible explanations of how and when the genus achieved its present, remarkably large distribution. A lot more work needs to be done on the populations from the northwest, and exploration needs to be undertaken in areas where these frogs have not yet been sought, in order to give the answers we are looking for. But what remains unchanged is that the populations in Ambohitantely and other highland humid forest fragments are under existential threat from the fires that are scouring the country’s highlands, and money invested in protecting those habitats is money well spent.
Finally, for me personally, this description represents a personal milestone: it is my 100th peer-reviewed publication! I am really proud to have reached this milestone in just over a decade of publishing, and am looking forward to sharing many more discoveries and stories with the world in the years to come.
