Abstract
The nymph of Atopopus tarsalis Eaton, 1881, type species of the genus, is described in detail for the first time. The egg stage is also presented. Endemic to Borneo, A. tarsalis nymphs exhibit a peculiar behaviour, being able to climb boulders and stay out of the water for periods of at least 20 minutes without dehydration. Hypotheses for such behaviour are briefly discussed such as drift and predation avoidance.References
Braasch D. (2005). Neue Arten der Gattung Atopopus und Afronurus aus Südostasien sowie einige Bemerkungen zur Gattung Asionurus von Malaysia (Insecta: Ephemeroptera: Heptageniidae). Entomologische Abhandlungen, 62(2), 165–174.
Brittain J.E. & Eikeland T.J. (1988). Invertebrate drift - A review. Hydrobiologia, 166, 77–93.
Derleth P. (2003). Benthic macroinvertebrates and logging activities: a case study in a lowland tropical forest in East Kalimantan (Indonesian Borneo). School of Architecture, Civil and Environmental Engineering. Lausanne, Swiss Federal Institute of Technology: 174 pp.
Dudgeon D. (1993). The effects of spate-induced disturbance, predation and environmental complexity on macroinvertebrates in a tropical stream. Freshwater Biology, 30(2), 189–197.
Eaton A.E. (1881). An announcement of new genera of the Ephemeridae (continued). Entomologist Monthly Magazine, 18, 21–27.
Harker J.E. (1950). Australian Ephemeroptera Part I. Taxonomy of New South Wales species and evaluation of taxonomic characters. Proceedings of the Linnaean Society of New South Wales, 75(1–2), 1–34.
Hubbard M.D. & Campbell I.C. (1996). Catalogue of the Australian mayflies, recent and fossil (Insecta, Ephemeroptera). Australian Society of Limnology, Special Publication, 11, 1–43.
Huhta A., Muotka T., Juntunen A. & Yrjönen M. (1999). Behavioural interactions in stream food webs: the case of drift-feeding fish, predatory invertebrates and grazing mayflies. Journal of Animal Ecology, 68, 917–927.
Huhta A., Muotka T. & Tikkanen P. (2000). Nocturnal drift of mayfly nymphs as a post-contact antipredator mechanism. Freshwater Biology, 45(1), 33–45.
Kluge N. (2004). The phylogenetic system of Ephemeroptera. Dordrecht, Kluwer Academic Publishers, 442 pp.
Lancaster J. (1992). Diel variations in the effect of spates on mayflies (Ephemeroptera: Baetis). Canadian Journal of Zoology, 70, 1696–1700.
McIntosh A.R., Peckarsky B.L. & Taylor B.W. (2002). The influence of predatory fish on mayfly drift: extrapolating from experiments to nature. Freshwater Biology, 47(8), 1497–1513.
Melo A.S. & Froehlich C.G. (2004). Colonization by macroinvertebrates of experimentally disturbed stones in three tropical streams differing in size. International Review of Hydrobiology, 89(3), 317–325.
Nolte U., Tietbohl R.S. & McCafferty W.P. (1996). A mayfly from tropical Brazil capable of tolerating short-term dehydration. Journal of the North American Benthological Society, 15(1), 87–94.
Ulmer G. (1920). Neue Ephemeropteren. Archiv für Naturgeschichte, Abteilung A, 11, 1–80.
Wang T.-Q. & McCafferty W.P. (1995). First larval descriptions, new species and evaluation of the Southeast Asian genus Atopopus (Ephemeroptera, Heptageniidae). Bulletin de la Société d'Histoire Naturelle de Toulouse, 131, 19–25.