A review of the genus Mantella (Anura, Ranidae, Mantellinae): taxonomy, distribution and conservation of Malagasy poison frogs. 
Miguel Vences, Frank Glaw, Wolfgang Böhme  

In this paper 17 species of Mantella are recognised and the genus is partitioned into six species groups, which can be distinguished, by a combination of bioacoustics, morphological, osteological and colouration characters.  The following species and species groups are recognised: 

Mantella betsilio group 
(M. betsilio, M. viridis, M. expectata, Mantella sp.1 and one new species described within);

Mantella laevigata group 
(M. laevigata); 

Mantella cowani group 
(M. cowani, M. baroni, M. affinis baroni, M. haralmeieri, M. nigricans);

Mantella bernhardi group 
(M. berhardi);

Mantella madagascariensis group 
(M. madagascariensis, M. pulchra);

Mantella aurantiaca group 
(M: aurantiaca, M. crocea, M. milotympanum).  

This partition is of rather high resolution and some of the groups may also be regarded as super-species or species complexes.  A detailed type re-examination showed that M. madagascariensis and M. baroni represent two different species which are very similar in dorsal colouration, but M. madagascariensis can be distinguished by some characters of ventral colouration, horseshoe marking on the throat, reddish colour ventrally on the femur) and morphology (large inner metatarsal tubercle) from M. baroni.  

Specimens from Marojezy preserved in the Paris Museum are catalogued as M. cowani nigricans and must therefore be considered as syntypes of this taxon.  The syntype series is heterogeneous also containing specimens of M. laevigata, the name nigricans is stabilised by designation of a lectotype corresponding to an M. cowani form from Marojezy.  The name Mantella cowani nigricans  (Guibe 1978) is revalidated and raised to species rank as Mantella nigricans.

A big problem in Mantella systematics is that in recent years hobbyists increasingly tend to publish 'phantom' scientific names without type designation, which in several cases lead to nomenclatural available new nominal taxa.  Two phantom names, which must be considered as nomenclaturally available, are Mantella aurantiaca milotympanum and Mantella aurantiaca rubra (both Staniszewski, 1996).  We consider the name rubra to be a synonym of M. aurantiaca but preliminarily attribute species status to M.  milotympanum. 

Lectotypes (in addition to M. nigricans) are designated for M. cowani, M. aurantiaca M. betsilio, M. attemsi  (synonym of M. betsilio), M. aurantiaca rubra (synonym of M. aurantiaca) and M. milotympanum (from published figures).  Clarifications on types and type series are provided for several species.

In several species a large intraspecific colour variation was recorded (M. aff. baroni M. nigricans, M. crocea).  A detailed review of all published Mantella localities and the corresponding voucher specimens results in updated distribution maps.  Sympatric and syntopic occurrence was reliably only found in species from different species groups; the species within each group being allopatrically distributed.  Future studies on contact and hybrid zones may demonstrate that some of the species described should better be described as subspecies; however, for practical reasons we regard all taxa as species.

In an attempt to provide an estimate of the conservation status of each Mantella species data on distribution (maximum locality distance, number of known localities), habitat (primary forest restriction), trade intensity and attractiveness to the pet trade.  The species are grouped in various classes according to their potential vulnerability and priorities of research are outlined to get a more reliable database for such estimates.