Corresponding author: Thomas Kaltenbach (
Academic editor: Burgert Muller
A new genus of
Kaltenbach T, Gattolliat J-L (2021) A new genus from Madagascar with strongly enlarged labium (Ephemeroptera, Baetidae). African Invertebrates 62(2): 465–484.
With nearly one third of all mayfly species worldwide (ca. 1,100 species in 114 genera), the family
Madagascar is the fourth-largest island in the world with ca. 581,500 km2, situated ca. 400 km east of Africa in the Indian Ocean. Some 160 million years ago, the supercontinent Gondwana started to break apart and the eastern section of this land mass, incl. today’s Madagascar, drifted eastwards. Approximately 140 million years ago, the landmass composed of Madagascar and the Indian subcontinent was completely separated from the African landmass, without subsequent land connection. Finally, around 80 million years ago, Madagascar split from the Indian subcontinent and stayed isolated until today. This long-term isolation in combination with a high topographic and geological complexity, supporting speciation on the island, is responsible for the outstanding biological richness and the high level of endemism in Madagascar (
Until 1990, the Malagasy mayflies, as other aquatic insects, remained very poorly known. Only a few reports were made based on a limited number of specimens and localities (
The present study is based on two nymphs collected in 2001 and 2003 in two different locations in Madagascar. The type-locality was sampled fourteen times during biodiversity assessments of Malagasy streams between 1993 and 2003 by teams of the French ORSTOM (Office de la recherche scientifique et technique outre-mer) and the Museum of Zoology, Lausanne (
The specimens were collected in 2001 and 2003 from two different locations in the same area of Madagascar. Specimens were preserved in 70%-80% ethanol. Nymphs were dissected in Cellosolve (2-Ethoxyethanol) with subsequent mounting on slides in Euparal medium, using an Olympus SZX7 stereomicroscope.
The DNA of one specimen was extracted using non-destructive methods allowing subsequent morphological analysis (see
Drawings were made using an Olympus BX43 microscope. Photographs of nymphs were taken with a Canon EOS 6D camera and processed with Adobe Photoshop Lightroom (
Distribution maps were generated with SimpleMappr (
The terminology used in the manuscript follows
The new species is established based on morphological characters.
Unknown.
(Fig.
Madagasikara is the Malagasy name of Madagascar.
Both mandibles with lateral margins convex. Basal half laterally with short, fine, simple setae.
(Fig.
Larvae were collected in two pristine streams running in relatively preserved natural tropical rain forests. Environmental parameters of the type-locality: width 2–3m, depth 0.1–0.2m, velocity 0.6–0.8 m/s, temperature 16–18 °C. The riverbed was a mix of sand, gravel and rocks with a few small waterfalls and very limited riparian vegetation. Mayfly fauna is very diversified with around twenty species of
African genera of Protopatellata were previously assigned either to the
The following characters differentiate
Elongated claws with two rows of numerous denticles increasing in length toward the apex are also typical for species of
The legs of
The labrum with straight lateral margins and a largely V-shaped distal margin is also rather unusual among
A remarkable setation on the antennal base is also present in two Neotropical Anteropatellata:
As a conclusion, the relationship of
The description of
The number of localities and different habitats sampled in Madagascar are relatively high, but there are still areas where no collection activities have occurred (especially in the Northeast of the island including the Masoala Peninsula). Taking into account the obvious biological richness of this island, it would be prudent to assume that the number of genera and species of
We sincerely thank Ranalison Oliarinony (Antananarivo, Madagascar), and the participants of the mission in 2003 (Michel Sartori, Olivier Glaizot (