A new catfish belonging to sisoridae – Pseudolaguvia lapillicola – is described by Britz, Anvar and Raghavan. (link to the paper will be added here at a later stage).
This species was found along with Pangio ammophila, at Kumaradhara in southern Karnataka and was collected during their January-February 2012 explorations. As we know the eel-loach was “sand-loving” (hence the name), this species was found nearby (the sand) in the gravels – hence named lapillicola – “lapilli”=gravel and “colere“= dwell (or incola = resident, incolere = dwell [in]).
This species is yet another biogeographic puzzle. The relatives of this species, save one – Pseudolaguvia austrina, are all found in the North Eastern Indian region and in Myanmar (base of himalayas). In other words only one relative of this new species is found in the peninsular Indian region P. austrina from Bharathapuzha more southwards from Kumaradhara.
It is interesting that a similarly coloured (yellow brown background coloured) Glyptothorax fish was found together (co-inhabiting or “co-incola” 🙂 ) at the same location, which looked like a Glyptothorax madraspatanum. It is also interesting that Pseudolaguvia austrina from Bharathapuzha was found to co-inhabit with Glyptothorax anamalensis (Anvar Ali personal comm.). Remember that Glyptothorax and Pseudolaguvia both belong to Sisoridae (Family) and these genera are found living together at least in more than one location (according to the authors, it smells fishy!!!!).
What was the adaptive trajectory that these similar looking (and sized) fishes took to co-exist in a similar habitat, lot of work (for the authors) to follow up with.
These same set of authors have found two other species recently, Pangio ammophila which has all its closest relatives in the South East Asian Region, and Dario urops which has all its relatives in North Eastern (NE) India, Myanmar and South East (SE) Asia.
This has been a hot topic of research during the past, not only these – but many other species like Lepidopygopsis typus (relatives in Himalayas and Central Asia), Pterocryptis wynaadensis (relatives in NE India, China etc.), which show this kind of distribution are known – albeit rare. For a better treatment on this subject (discontinuous distribution) readers are advised to read the paper available in this link.
Till recently it was thought to be a rarity to find a species with its congener’s in distant places like NE India (through) SE Asia. But, nowadays we hear it a lot, Dario, Pangio, Pseudolaguvia etc. from the Western Ghats. What does this say?
The species mentioned here (and also listed in the above links) have common ancestry. That means Pangio’s form WG and SE Asia have a common ancestry, Dario from WG and Dario’s and Badises from SEAsia have a common ancestry, Pseudolaguvia from WG and NE India and SE Asia have a common ancestry. So again – what does it say?
All these regions (geographical regions) have a common ancestry. Easily said but not well understood.
These zoological explorations are thus shedding light on different aspects of the formation of a region and formation of the biodiversity seen there. We need more such explorations and studies to understand this remarkable evolutionary process. Evolution of the continents, evolution of the taxa and the dispersal and distribution of organisms.
Another thing to be noted here is that more and more cases of discontinuous distribution (of species) are found “now” simply because – people explore nature more (than in the past) – for example these guys found because they looked, more such examples and species may be there “unknown” in the WG and more people are needed to study nature!!
Britz, R., Ali, A. & R. Raghavan. (2013). Pseudolaguvia lapillicola, a new species of catfish from Peninsular India (Teleostei: Sisoridae). Ichthyological Exploration of Freshwaters, 23: 289-295.
NB: [competing interests] I assisted the authors in their field work.