A preliminary phylogeny of Prosopistomatidae (Ephemeroptera) based on morphological characters of the larvae, and an assessment of their distribution

Abstract

Until recently, only four species of the monogeneric family Prosopistomatidae were described from the Afrotropical realm; one from Madagascar, and three from sub-Saharan Africa. Recent studies have revealed the family to be more diverse, with a further five species from Madagascar, one from the Comores archipelago and seven from sub-Saharan Africa, which are currently in the process of being formally described. This brings the total number of known species globally to 34. Phylogenetic analysis of morphological features of the larvae reveals that the type species, Prosopistoma variegatum Latreille, 1883, a Madagascan species, along with two other Madagascan species, belongs to a clade which is different to the majority of other Afrotropical species. It is more closely related to the European species, the species from the Middle East and several of the species from the Oriental and Australasian regions. One possible explanation is diversification of this ‘P. variegatum’ clade after Madagascar and India separated from Africa. The precursors of this clade may have been carried northwards on the Indian Plate, and subsequently dispersed to Europe, and to Australia via the Indo-Pacific islands. A concurrent dispersal of the now predominantly mainland African clade may have occurred and, in Madagascar and the Oriental realm, members of this group occur sympatrically with, or in close geographic proximity to, members of the ‘P. variegatum’ clade.

Keywords:

• Ephemeroptera
• Prosopistomatidae
• phylogeny
• Gondwana
• distribution
• dispersal
• vicariance

Acknowledgements

My grateful thanks to the following people: for hosting me and providing material: W. Patrick McCafferty (Purdue University, West Lafayette); Michel Sartori (Museum of Zoology, Lausanne). Jean-Marc Elouard, for additional material from West Africa and help with localities, both in West Africa and Madagascar. Mark Graham, Bonani (Diks) Madikizela, Pumza Maseti, Rob Palmer and Nick Rivers-Moore for providing me with material from new localities in Africa. Roger Bills and Ferdy de Moor for trying to help me find the ‘extinct’ species in the Olifants Rivers (W. Cape). Elaine de Coninck (Musée Royal de l'Afrique Centrale, Turveren) for the loan of Paulian's material from the Democratic Republic of the Congo (DRC). Janice Peters (Florida A and M University, Tallahassee) for the loan of the species from Anjouan, Comores. David Goodger (the Natural History Museum, London) for use of material and office space. Michel Sartori and Jean-Luc Gattolliat for help with French translations. Gillian McGregor (Rhodes University Geography Department, Grahamstown) and Willem Coetzer (South African Institute for Aquatic Biodiversity, Grahamstown) for guidance with ArcView GIS, and to Willem for helping with the final maps. Michael Hubbard for providing several obscure references. Rebecca Tharme (then of the Freshwater Research Unit, University of Cape Town) for information about the western Cape species; Santiago Robles and Manuel Toro (Centre for Hydrographic Studies, Madrid, Spain) for material from Spain. The National Research Foundation (South Africa) for providing funding for this project. The Albany Museum (under the Department of Sports, Recreation, Arts and Culture) for giving me time to work on this project. The Willi Hennig Society for making the program TNT available freely. My supervisors, Ferdy de Moor and Martin Villet, for advice during the project. The editor for refereeing this paper and pointing out important misconceptions. My family and friends for their patience and encouragement.