© 2017 The Linnean Society of London, Zoological Journal of the Linnean Society, 2017, 181, 727–756 727 Zoological Journal of the Linnean Society, 2017, 181, 727–756. With 9 figures. Freshwater planarian diversity (Platyhelminthes: Tricladida: Dugesiidae) in Madagascar: new species, cryptic species, with a redefinition of character states GIACINTA ANGELA STOCCHINO 1 *, RONALD SLUYS 2 , MARTA RIUTORT 3 , EDUARD SOLÀ 3 and RENATA MANCONI 1 1 Dipartimento di Scienze della Natura e del Territorio, Via Muroni 25, University of Sassari, Sassari I-07100, Italy 2 Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands 3 Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain Received 12 October 2016; revised 4 January 2017; accepted for publication 19 March 2017 The present paper describes three new species of freshwater flatworm of the genus Dugesia from Madagascar, by applying an integrative approach to taxonomy, combining morphological and molecular information. Further, molec- ular data uncovered a cryptic species diversity, enabling taxonomic assignment of several asexual populations to already known species and thus pointing to at least two more species of the genus Dugesia present on Madagascar. The paper redefines several character state conditions in species of Dugesia, relating to three types of accessory structures of the copulatory apparatus: penial annexes, atrial folds and valves, and adenodactyls. It also provides a more precise definition of character states concerning the course of the ejaculatory duct through the penis papilla. In order to be able to examine the taxonomic status, phylogenetic position and biogeography of the Malagasy Dugesia species, molecular phylogenetic analyses were performed on many populations from Madagascar and also on rep- resentatives of 27 species from across the geographic range of the genus. Our results show that Madagascar is not only rich in number of species but also in genetic diversity, thus highlighting that the biodiversity and endemicity of Malagasy freshwater planarians has been underestimated. ADDITIONAL KEYWORDS: Afrotropical Region – biodiversity – biogeography – Dugesia – integrative taxonomy – molecular systematics – morphology – new species – phylogenetic characters. INTRODUCTION Notwithstanding the high profile that Madagascar has as a global hotspot for biodiversity (cf. Roy, 2016 and references therein), including land flatworms (cf. Sluys, 1999), its freshwater planarian fauna has been the object of only very few studies. The first record dates back to the paper of Grandidier & Petit (1932) , merely reporting the presence of freshwater triclads on this island. The first detailed report was published by De Beauchamp (1952), with the description of a new species of Dugesia Girard, 1850. After almost four decades De Vries (1988a) described two other new Dugesia species, one of which was based on material left unidentified by De Beauchamp. To further our limited knowledge of Madagascan planarian species richness, several lentic and lotic freshwater bodies were recently investigated in unex- plored areas of the central High Plateau, both along its Eastern and Western slopes. This has recently resulted in the description of a new species of Dugesia (Stocchino, Sluys & Manconi, 2014), thus raising the species richness of freshwater triclads for Madagascar to a meagre four species. In the present paper we describe three other new species of freshwater triclads for the genus Dugesia, by applying an integrative approach to taxonomy, combining *Corresponding author. E-mail: stocchin@uniss.it [Version of Record, published online 10 July 2017; http:// zoobank.org/ urn:lsid:zoobank.org:pub:FA43B172-3F05- 4F1D-9465-A9B2FEBE20A5] Downloaded from https://academic.oup.com/zoolinnean/article/181/4/727/3946141 by guest on 15 February 2024