Mayflies

A common hypothesis for the high biodiversity of mountains is the diversification driven by orogeny creating conditions for rapid in situ speciation of resident lineages. The Caucasus is a young mountain system considered as a biodiversity hotspot; however, the origin and evolution of its diversity remain poorly understood. This study focuses on mayflies of the subgenus Caucasiron, one of the most diversified stenotopic mayflies inhabiting various types of streams throughout the Caucasus. Using the time-calibrated phylogeny based on two mi-tochondrial (COI, 16S) and three nuclear (EF-1α, wg, 28S) gene fragments, we tested the role of Caucasian orogeny in biogeography, diversification patterns, and altitudinal diversification of Caucasiron mayflies. We found that orogeny promoted the lineage diversification of Caucasiron in the Miocene. The highest diversification rate corresponding with the uplift of mountains was followed by a significant slowdown towards the present suggesting minor influence of Pleistocene climatic oscillations on the speciation. The Caucasiron lineages cluster into three principal clades originating in the Upper Miocene. We found a strong support that one of the three clades diversified via allopatric speciation in the Greater Caucasus isolated in the Parathetys Sea. The other two clades originating most likely outside the Greater Caucasus diversified towards high and low altitude, respectively , indicating possible role of climatic factors and/or passive uplift on their differentiation. Current high Caucasiron diversity in the Greater Caucasus is a result of in situ speciation and later immigration from adjacent mountain ranges after the Parathetys Sea retreat. Our phylogeny supported the monophyly of Rhithrogeninae, Epeorus s.l., Caucasiron, and Iron. Epeorus subgenus Ironopsis was found paraphyletic, with its European representatives more closely related to Epeorus s.str. than to Iron. Therefore, we rearranged taxa treated within Ironopsis to comply with the phylogeny recovered herein.

Temperature and daily emergence of seven genera of Ephemeroptera (Insecta) in a cloud forest stream of tropical Andes. Daily emergence of mayflies in Neotropical rivers and their causes have been poorly studied. In temperate zones, this process is better known and attributed to several factors. In this work, we studied the daily emergence of subimagines of several Ephemeroptera genera in La Picón River of a Venezuelan Andean cloud forest and its relation with changes of environmental temperature. Four emergence traps were placed along a reach of 50 m of the stream, each one was examined each two hours in a 24 hr cycle to capture the newly emerged subimagos. This procedure was repeated for eight dates between November-2007 and February-2008 for a total of 32 observations in each sampling hour. The subimagos were reared to adults and identified to genus. The relative density of emergence per trap was calculated for each genus and sampling hour. Water and air temperature were measured each hour during the daily cycle of observation, and the averages of temperature and hour-degrees of air and water were calculated for each hour from the eight dates studied. Seven genera were identified: Leptohyphes Eaton, 1882 and Haplohyphes Allen 1966 (Leptohyphidae); Prebaetodes Lugo-Ortiz and McCafferty, 1996, Andesiops Lugo-Ortiz and McCafferty, 1999, Baetodes Needham and Murphy, 1924 and Americabaetis Kluge, 1992 (Baetidae); and Thraulodes Ulmer, 1920 (Leptophlebiidae); being the more abundant Leptohyphes (38.4 %) and Thraulodes (20.5 %). The emergence occurred between 11:00 am and 23:00 pm showing the following: a) an emergence initiated during daylight hours by organisms of Leptohyphes, Prebaetodes and Haplohyphes; b) a nocturnal emergence, in Thraulodes, Andesiops, Baetodes and Americabaetis; and c) two peaks: one diurnal produced by Leptohyphes and other nocturnal with predominance of Thraulodes. These results are the first records on the diurnal daily emergence in Andesiops, Prebaetodes, Americabaetis, Haplohyphes, and Leptohyphes, as well as the nocturnal emergence in Thraulodes. It was evidenced that Leptohyphes, with small nymphs (average head width = 1.05 mm) needed to accumulate less hour-degrees to initiate the emergence than those required by Thraulodes whose nymphs are larger (average head width = 2.01 mm). This disparity in the emergence energy requirements must be consequence of differences between the sizes of mature nymphs of both genera; facts which rely on the constancy of sizes shown by these taxa along an altitudinal-thermal gradient and the little daily and seasonal variability of water temperature in La Picón River. In the daily lapse when the emergence occurred, the air and water average temperatures were higher than those registered in the no-emergence lapse; therefore; it is suggested that during the daily lapse, when this process occurs, the environment is thermally favorable for the emergence of subimagos and their survival out of water. Rev. Biol. Trop. 64 (1): 117-130. Epub 2016 March 01.

The first winged insects underwent profound morphological and functional transformations leading to the most successful animal radiations in the history of earth. Despite this, we still have a very incomplete picture of the changes in their genomes that underlay this radiation. Mayflies (Ephemeroptera) are one of the extant sister groups of all other winged insects and therefore are at a key phylogenetic position to understand this radiation. Here, we describe the genome of the cosmopolitan mayfly Cloeon dipterum and study its expression along development and in specific organs. We discover an expansion of odorant-binding proteins, some expressed specifically in the breathing gills of aquatic nymphs, suggesting a novel sensory role for gills. In contrast, as flying adults, mayflies make use of an enlarged set of opsins and utilise these visual genes in a sexually dimorphic manner, with some opsins expressed only in males. Finally, to illuminate the origin of wings, we identify a cor...

Abrams Creek drainage was surveyed for adult mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) during summer 2001 as part of the All Taxa Biodiversity Inventory in the Great Smoky Mountains National Park (GRSM). Nine reaches were collected, up to five times, using primarily ultraviolet light trapping. Of the 35,710 specimens examined, 164 species resulted. These consisted of 35 species of mayflies, 36 stoneflies, and 93 caddisflies. Eight species are new to Tennessee, while 39 are new GRSM records. Three rarely collected mayflies, Epeorus vitreus (Walker), Leucrocuta thetis (Traver), and Nixe spinosa (Traver), were taken. Rare caddisflies included Ceratopsyche macleodi (Flint), Cheumatopsyche helma Ross, Hydroptila chattanooga Frazer and Harris, H. talladega Harris, and Chimarra augusta Morse. No rare stoneflies were collected. Additional specimens of two undescribed (but known to specialists) species were taken in Goera (Trichoptera) and Isoperla (Plecoptera). Specimens of Hydroptila nr. amoena Ross (Trichoptera) and a Caenis nr. mccafferti Provonsha (Ephemeroptera) are possibly new to science, but require more specimens and study. More effort concentrated in southwestern GRSM and in Ephemeroptera and Trichoptera should yield additional significant records.

Aspectos da biologia e ecologia de Callibaetis guttatus (Baetidae) e Caenis cuniana (Caenidae) foram estudados entre 1986 e 1991 no Brejo-canal de Itaipuaçu, Maricá, RJ. O tempo de duração da subimago de C. guttatus indica que essa fase seja restrita à noite, o que possivelmente representa uma adaptação contra a perda excessiva de água. Quanto à C. cuniana, a reprodução por partenogênese parece constituir uma importante adaptação às condições ambientais da localidade.

Benthic macroinvertebrates are very small organisms living among stones, logs, sediments, and aquatic plants within freshwater systems. Freshwater can be described as water with low salinity that is frequently used for domestic purposes, irrigation and is essential for life on earth. Benthos inhabit various freshwater systems and are comprised of a large diversity of organisms that include; mayflies, stoneflies, caddisflies, beetles, midges, crane flies, dragonflies and others. Non-insect members of the benthic macroinvertebrate community are snails, clams, aquatic worms and crayfish. Freshwater has a salinity between 0.0 to 5.0‰ and only 2.5% of the earth’s water is freshwater. Of the 2.5% freshwater on earth, 0.49% and 20.9% are found in rivers and lakes respectively (Kozminski, 2017).

Collections of macroinvertebrates made between 1976 and 1996 were used to establish distributional records for Ephemeroptera in the upper New River. Fifty species, 28 genera, and 13 families of Ephemeroptera are documented. The dominant species of mayflies were categorized into seasonal groups based on larval development patterns and adult emergence periods.

Mayfly Caenis moesta (syn. Caenis horaria), ecology, depth distribution (max biomass at 2-4m), growth question, temperature dependance, biomass, production, seasonal P/B ratio (8.5-10.2)

Original name: Акопян, С.А., Островский, И.С. 1984. Экoлoгия и пpoдукция пoдeнoк в oзepe Ceвaн. Сборник: Лимнoлoгия гopныx вoдoeмoв. Ереван: 3-4.

This study represents the first combined molecular and morphological analysis for the mayfly family Ephemerellidae (Ephemeroptera), with a focus on the relationships of genera and species groups of the subfamily Ephemerellinae. The phylogeny was constructed based on DNA sequence data from 3 nuclear (18S rDNA, 28S rDNA, histone H3) and 2 mitochondrial (12S rDNA, 16S rDNA) genes, and 23 morphological characters. Taxon sampling for Ephemerellidae included exemplars from all 25 extant genus groups and additional representatives from those genera with the highest diversity. Ephemerellidae appears to consist of three major clades. Ephemerella, the largest genus of Ephemerellidae, and Serratella were not supported as monophyletic, and each had representatives in two of the three major clades. However, the genera Drunella and Cincticostella were supported as monophyletic. Lineages strongly supported as monophyletic include a grouping of the Timpanoginae genera Timpanoga, Dannella, Dentatell...