Abstract
We describe Graptodytes eremitus n.sp. (Coleoptera, Dytiscidae), a depigmented, microphthalmic stygobitic species found in a pool in the deep area of a cave in the High Atlas of Morocco. To establish its phylogenetic position we inferred a molecular phylogeny of the genus Graptodytes Seidlitz, using ca. 1.7 Kb of four mitochondrial genes for 18 of the 23 previously known species and subspecies of the genus. Graptodytes can be separated in three well supported main lineages, 1) the G. flavipes lineage (apex of median lobe narrow in ventral view), 2) the G. granularis lineage (apex of median lobe expanded and strongly asymmetrical in ventral view), and 3) the G. varius lineage (apex of median lobe expanded but symmetrical in ventral view). The G. varius lineage includes the G. aequalis and G. varius groups, the latter including G. eremitus n.sp. as sister to G. delectus Wollaston (Canary Islands) plus the G. varius complex. A molecular clock approach, using a calibration rate of 2.3% divergence/MY for the combined mitochondrial sequence, estimated the origin of the diversification within the genus at ca. 7MY (late Miocene), and the origin of G. eremitus n.sp. at ca. 2 MY (Pliocene-Pleistocene boundary).References
Bameul, F. (1989) Description de Rhithrodytes, nouveau genre d'Hydroporinae d'Europe et d'Afrique du Nord: analyse phylogénétique et biogéographie (Coleoptera: Dytiscidae). Annales de la Société Entomologique de France N.S., 25, 481–503.
Brower, A.V.Z. (1994) Rapid morphological radiation and convergence among races of the butterfly Heliconius erato inferred from patterns of mitochondrial-DNA evolution. Proceedings of the National Academy of Sciences of the United States of America, 91, 6491–6495.
Castro, A. & Delgado, J.A. (2001) Iberoporus cermenius, a new genus and species of subterranean water beetle (Coleoptera: Dytiscidae) from Spain. Aquatic Insects, 23, 33–43.
Drummond, A. & Rambaut, A. (2007) BEAST: Bayesian evolutionary analysis by sampling trees. BMC Evolutionary Biology, 7, 214.
Fery, H. (1994) Taxonomische Notizen zu Graptodytes sedilloti (Régimbart 1877) und Graptodytes phrygius Guignot 1943 nebst Beschreibung von Graptodytes bussleri n. sp. vom Golan (Coleoptera: Dytiscidae). Entomologische Zeitschrift, 104, 389–402.
Fery, H. (1995) Notizen zur aequalis-Gruppe und weiteren Arten der Gattung Graptodytes Seidlitz 1887 (Coleoptera: Dytiscidae). Entomologische Zeitschrift, 105, 33–51.
Guignot, F. (1959) Revision des hydrocanthares d'Afrique (Coleoptera Dytiscoidea). Deuxième partie. Annales du Musée Royal du Congo Belge Tervuren, Série in 8º Sciences Zoologiques, 78, 323–648.
Hendrich, L. (1993) Ein neuer Schwimmkäfer der Gattung Graptodytes Seidlitz 1887 (Coleoptera: Dytiscidae) aus Uzbekistan - Graptodytes snizeki n. sp. Entomologische Zeitschrift, 103, 392–398.
Howarth, F. (1980) The zoogeography of specialized cave animals: a bioclimatic model. Evolution, 34, 394–406.
Huelsenbeck, J.P. & Ronquist, F. (2001) MrBAYES: Bayesian inference of phylogenetic trees. Bioinformatics, 17, 754–755.
Jeannel, R. (1907) Description d'un Hydroporus (Graptodytes) nouveau du nord de l'Afrique (Col.). Bulletin de la Société Entomologique de France, 1907, 18–21.
Katoh, K. & Toh, H. (2008) Recent developments in the MAFFT multiple sequence alignment program. Briefings in Bioinformatics, 9, 286–298.
Leys, R., Watts, C.H.S., Cooper, S.J.B. & Humphreys, W.F. (2003) Evolution of subterranean diving beetles (Coleoptera: Dytiscidae: Hydroporini, Bidessini) in the arid zone of Australia. Evolution, 57, 2819–2834.
Miller, K.B., Gibson, J.R. & Alarie, Y. (2009) North American stygobiontic diving beetles (Coleoptera: Dytiscidae: Hydroporinae) with description of Ereboporus naturaconservatus Miller, Gibson and Alarie, new genus and species, from Texas, U.S.A. The Coleopterists Bulletin, 63, 191–202.
Nilsson, A.N. (2001) World Catalogue of Insects, Vol. 3. Dytiscidae. Apollo Books, Stenstrup.
Nilsson, A.N. (2003) Dytiscidae. In: I. Löbl & A. Smetana (eds), Catalogue of Palaearctic Coleoptera. Volume 1: Archostemata, Myxophaga, Adephaga. Apollo Books, pp. 35–78.
Nilsson, A.N. & Holmen, M. (1995) Fauna Entomologica Scandinavica, vol. 32. The aquatic Adephaga (Coleoptera) of Fennoscandia and Denmark. II. Dytiscidae. E. J. Brill, Leiden.
Papadopoulou, A., Anastasiou, I., Keskin, B. & Vogler, A.P. (2009) Comparative phylogeography of tenebrionid beetles in the Aegean archipelago: the effect of dispersal ability and habitat preference. Molecular Ecology, 18, 2503–2517.
Régimbart, M. (1905) Note sur le Siettitia balsetensis. Bulletin de la Société Entomologique de France, 1905, 252.
Ribera, I., Beutel, R.G., Balke, M. & Vogler, A.P. (2002) Discovery of Aspidytidae, a new family of aquatic Coleoptera. Proceedings of the Royal Society of London, Series B, 269, 2351–2356.
Ribera, I., Fresneda, J., Bucur, R., Izquierdo, A., Vogler, A.P., Salgado, J.M. & Cieslak, A. (2010) Ancient origin of a Western Mediterranean radiation of subterranean beetles. BMC Evolutionary Biology, 10, 29.
Ribera, I. & Vogler, A.P. (2004) Speciation of Iberian diving beetles in Pleistocene refugia (Coleoptera, Dytiscidae). Molecular Ecology, 13, 179–193.
Ribera, I., Vogler, A.P. & Balke, M. (2008) Phylogeny and diversification of diving beetles (Coleoptera : Dytiscidae). Cladistics, 24, 563–590.
Seidlitz, G. (1887) Bestimmungs-Tabelle der Dytiscidae und Gyrinidae des europäischen Faunengebietes. Verhandlungen des Naturforschenden Vereines in Brünn, 25(1886), 3–136.
Simon, C., Frati, F., Beckenbach, A., Crespi, B., Liu, H. & Flook, P. (1994) Evolution, weighting, and phylogenetic utility of mitochondrial gene-sequences and a compilation of conserved polymerase chain-reaction primers. Annals of the Entomological Society of America, 87, 651–701.
Stamatakis, A., Hoover, P. & Rougemont, J. (2008) A rapid bootstrap algorithm for the RAxML Web servers. Systematic Biology, 57, 758–771.
Toledo, M. & Hosseinie, S. (2003) A new species of Metaporus Guignot from southern Iran (Coleoptera: Dytiscidae). Koleopterologische Rundschau, 73, 59–64.
Zaitzev, P. (1927) Die Dytiscidenfauna von Kaukasusländern. Travaux de la Station Biologique du Caucase du Nord, 2, 1–42.
Zimmermann, A. (1932) Monographie der paläarktischen Dytisciden. III. Hydroporinae (3. Teil). Koleopterologische Rundschau, 18, 69–111.