by Matthew Cobb
Madagascar continues to live up to its reputation as a biodiversity hotspot with the discovery of this critter:
It is a new carnivorous mammal, Salanoia durrelli, or Durrell’s vontsira. (“Durrell” is after Gerald Durrell, author of My Family & Other Animals and many other popular naturalist books, and founder of the Durrell Trust, which has a zoo devoted entirely to saving endangered species, on Jersey island. He was also the brother of author Lawrence Durrell.) A vontsira is a Malagasy mongoose, of which, until the present report, there were thought to be five species.
According to the BBC website, the animal was first spotted in 2004, swimming in Lac Alaotra on Madagascar. In 2005 one of the animals was caught and another dead specimen was found. They seemed to be similar to the brown-tailed vontsira, which is found in the eastern forests of Madagascar, but there were also differences in the shape of the pads on its paws, and in its skull and teeth. These two specimens are the only ones known to science (assuming that the one seen in 2004 was not a different individual).
The dead animal and the samples were taken to the Natural History Museum in London, and the full description is published in Systematics and Biodiversity. According to the abstract, written in the usual impenetrable prose of science:
Evidence is presented from morphological observations, multivariate and molecular analyses on the taxonomic status of specimens of Salanoia newly discovered at Lac Alaotra, Madagascar, which resemble but are phenotypically highly divergent from the monotypic species S. concolor. A detailed comparative description is provided, together with information on the ecology of the region. Principal Component and Canonical Variate Analyses of craniodental morphometrics revealed high divergence supporting the status of a new species. Conversely, genetic distances from S. concolor based on the mitochondrial cytochrome b locus are small, not supporting new species status. A literature review indicates that some accepted species also exhibit low genetic distances at cytochrome b, which might be caused by rapid recent evolution, hybridization or introgression of mtDNA between lineages that otherwise might be genetically more distinct. Conflicting information from the analyses is discussed. Adaptation to highly divergent habitats might account for phenotypic plasticity, but the observed morphological difference is sufficiently great that the formal description as a new species is warranted. The biodiversity of Lac Alaotra and the importance of conservation issues are highlighted in relation to this discovery.
In other words, it has a different shaped head/teeth from its close relative Salanoia concolor, but some of its genes seem very similar. However, those particular genetic differences may not be relevant in indicating interspecies infertility (one of the main ways we define a species as a species – Jerry’s Big Book Speciation, written with Allen Orr, discusses eight different definitions…). The authors conclude that because it doesn’t look like S. concolor, it really is a different species. I can’t tell you any more than that as my prestigious university does not appear to have access to the journal… If you want to know more (in particular on mongoose evolution), I suggest you head over to Darren Naish’s excellent Tetrapod Zoology blog, who has more on this.
Finding a new species of arthropod is relatively straightforward – finding a new mammal is a relatively rare event. However, if that’s what you want to do, Madagascar is the place to go: ins 2006 the island has seen the discovery of three new species of mouse lemur (Microcebus jollyae, M. mittermeieri and M. simmoni) and a bat (Scotophilus marovaza).
h/t: Geoff North
Joanna Durbin; Stephan M. Funk; Frank Hawkins; Daphne M. Hills; Paulina D. Jenkins; Clive B. Moncrieff; Fidimalala Bruno Ralainasolo Investigations into the status of a new taxon of Salanoia (Mammalia: Carnivora: Eupleridae) from the marshes of Lac Alaotra, Madagascar.
Systematics and Biodiversity, 1478-0933, Volume 8, Issue 3, 01 September 2010, Pages 341 – 355