Species Of Ephemeroptera Research Articles

Assessment of the Impact of Heavy Metals on Benthic Communities at the Clinch River (Virginia): Evaluation of an Index of Community Sensitivity

Benthic communities (sampled once annually from 1986 to 1989) at stations impacted by copper and zinc were characterized by reduced species richness, reduced abundance, and a shift in community composition from sensitive to tolerant taxa. Benthic community structure varied annually due to fluctuations in stream discharge and improvements in water quality. Sensitivity of 13 dominant taxa to Cu was measured in outdoor experimental streams by exposing organisms to Cu (25 μg/L) for 10 d. Sensitivities (si), defined as proportioned reduction in abundance in treated streams relative to controls, ranged from 1.00 for several species of Ephemeroptera that were completely eliminated to −0.14 for taxa that increased in treated streams (Chironomidae: Orthocladiini). An index of community sensitivity (ICS) based on siand relative abundance of dominant taxa (pi) was developed for the Clinch River. The ICS was highly sensitive to heavy metals and useful for distinguishing reference and impacted stations. There was good agreement between the ICS and other community-level approaches in identifying impacted stations. We suggest that specific ICS values, based on siestimates of dominant taxa within a region, may be employed to predict the degree of metal impact in other streams within that region.

The effects of stream acidity on benthic invertebrate communities in the south‐eastern United States

SUMMARY1. Patterns in invertebrate community structure were determined from analysis of benthic samples taken quarterly for 1 year from four sites in the Great Smoky Mountains National Park (GSMNP). Sites ranged in baseflow pH from 4.5 to 6.8, with a corresponding range in inorganic monomeric aluminium concentrations from 3 to 197 μgl−1.2. Total invertebrate density (excluding Chironomidae) was correlated with pH (R2= 0.90, P<0.05). Density of Ephemeroptera was more highly correlated with pH than density of invertebrates in other taxonomic orders. Invertebrate density (total and density of different orders) was generally more strongly correlated with pH than to inorganic monomeric aluminium concentrations.3. Species richness declined from sixty‐nine species at the highest pH site to thirty‐three species at the lowest pH site. Richness of Ephemeroptera and Trichoptera was positively correlated with pH (R2= 0.96 in both cases). Trichopteran richness was also negatively correlated with inorganic monomeric Al concentrations (R2= 0.96, P< 0.05). Plecopteran richness was not related to stream acidity.4. Not all species of Ephemeroptera were negatively affected by low stream water pH. At low pH sites, Ameletus lineatus Traver (Family: Siphonoluridae) was relatively more abundant compared to other species of Ephemeroptera, and had greater biomass and greater weight per individual length than at higher pH sites.5. Differences in invertebrate community parameters among sites were not based on changes in food abundance. Although grazer densities were positively correlated with pH (R2= 0.93, P < 0.05), differences in density were not related to differences in food. To the contrary, lower grazer densities occurred at the lowest pH site where measured food abundance (algae) was highest. Likewise, shredder density increased with increasing pH but was correlated with standing stocks of benthic organic matter (BOM), which had generally higher standing stocks at lower pH sites.6. Transplants of two species of Ephemeroptera between sites differing in pH (6.4 v 5.0) resulted in increased mortality of organisms placed at lower pH sites. In another transplant experiment, differences in mortality were not observed, although surviving invertebrates at low pH sites had ×10 higher body burdens of aluminium following the transplant than invertebrates from the reference site.7. These results indicate that direct effects of pH and Al (affecting survival) were more important than indirect effects of food availability in determining changes in invertebrate community structure between the study sites.

The relationship between pH and community structure of invertebrates in streams of the Shenandoah National Park, Virginia, U.S.A.

SUMMARY1. A replicated natural experiment was used to assess the influence of pH and low alkalinity on abundance and richness of invertebrate families in streams draining catchments that receive acid deposition. Individual streams were used as the unit of replication, allowing conclusions to refer to a class of streams rather than to particular streams.2. We also controlled for several factors other than pH and alkalinity, including flow and temperature, that are recognized as determinants of invertebrate distribution. Samples were from indigenous rocks, standardized for size, surface area, and geology.3. Repeated measures analyses of variance (ANOVA) revealed that invertebrate abundance and richness were significantly lower at pH 5.8 than at pH 7.1 for the total community. Thirty per cent of the forty‐seven families exhibited significantly lower abundance at pH 5.8; thirteen families were absent at pH 5.8. Differences were greatest for Ephemeroptera: species richness was significantly lower at pH 5.8, and 71% of the twenty‐four species were either absent (seven) or found in reduced abundance (ten) in the acidic streams.4. Stream alkalinity is projected to continue to decrease with continued acid deposition in the Shenandoah National Park. Concurrent decreases in pH may lead to the absence or continued numerical decline of certain Ephemeroptera species in streams that acidify to less than pH 6.0 and/or 50μEql−1 alkalinity.

Distributions of Ephemeroptera, Plecoptera, and Trichoptera of three maritime catchments differing in pH

SUMMARY1. Two broad‐scale environmental influences affecting species of Ephemeroptera, Trichoptera and Plecoptera inhabiting riffle habitat of three study catchments in New Brunswick and Nova Scotia were stream size‐temperature‐related variables and acidity‐related variables.2. Species richness was most affected by acidity in tributaries of intermediate size <0.001<0.1m3s−1).3. Of the three insect orders investigated, mayfly species richness was affected most by acidity, and stonefly species richness affected least by this factor.4. Zoogeographical isolation of the Nova Scotian catchments resulted in absence of some species of low general abundance, but these species had little influence on the site classification by TWINSPAN analysis.5. Predaceous stoneflies were collected in greater numbers from circumneutral sites and predaceous caddisflies in greater numbers from the Nova Scotian sites.6. Although the Nova Scotian catchments have probably been historically acidic, due to high concentrations of organic acids, pH currently limits the distributions of many indigenous invertebrate species. These species may be vulnerable to the more recent, additional, anthropogenic acidification of these catchments.

Recovery of acid-sensitive species of ephemeroptera, plecoptera and trichoptera in river audna after liming

River Audna has been continuously limed on a full scale basis since 1985. Monitoring of benthic invertebrates of the river showed that the fauna was dominated by acid-tolerant species before liming and during the first year after the start of the treatment. Moderately acid-sensitive species, like Diura nanseni, Isoperla grammatica and Hydropsyche siltalia were found only in small numbers in a few localities in this period. In autumn 1987, the first appearance of the highly acid-sensitive mayfly Baetis rhodani was recorded at two stations in the main river. During the following years, this species colonized other localities and several other sensitive invertebrates, such as Heptagenia sulphurea, Caenis horaria, Hydropsyche pellucidula and Lepidostoma hirtum were also recorded. The change in faunal composition was highly significant compared to unlimed reference stations.

Aflagellate sperm in three species of leptophlebiidae (Ephemeroptera)

Immotile spermatozoa of 3 species of Ephemeroptera, Habroleptoides umbratilis, Habrophlebia eldae and Choroterpes picteti (Leptophlebiidae) are described. In all 3 species, sperm present a coccoidal shape and lack flagella or microtubule systems. Habrophlebia eldae shows very atypical sperm with a roundish nucleus and scarce cytoplasm, including an apical acrosome. By contrast, a fibrillar perforatorium and a mitochondrion are present in the sperm of H. umbratilis and C. picteti. This latter species also shows electron-dense bodies located in the space between the nucleus and the cell membrane. Our findings suggest that sperm/egg interaction should depend in leptophlebiids on the contraction of the genital duct muscles.

Size allometry in some Australian Mayfly Nymphs (Insecta: Ephemeroptera)

The relationship between total length and four other dimensions was investigated for seven southeastern Australian species of Ephemeroptera belonging to the families Siphlonuridae, Ameletopsidae Oniscigastridae and Coloburiscidae. Of the twenty‐eight relationships investigated, only nine cases of isometry were found. In most cases, there was a change in the allometric relationship late in nymphal life. However, within a given species, this change did not occur at the same total body length for all of the dimensions investigated, indicating that it was not associated with nymphs passing from an immature to a mature stage as suggested by Clifford (1970). In the case of Mirawara aapta the relationship between pro/mesonotum length and total length was more accurately described by an exponential function than a power function.

Effects of aerial spraying of insecticides on nontarget macrobenthos in a mountain stream

The effects of aerial spraying of an insecticide were investigated in a mountain stream using a drift net. The concentration of fenitrothion (organophosphorus insecticide) in the river water increased to ca. 20 μg liter −1 3 hr after the spraying and decreased exponentially to half the peak value after 2 hr. A large number of aquatic insects were found drifting after the spraying. The total number of individuals which drifted in the daytime after spraying reached nine times the number found the previous night. The total number of species which drifted during the 24 hr following the spray increased to 43 from 17 on the previous day. Before the insecticide spraying, the drifting benthos were almost entirely made up of three species of Baetis (Ephemeroptera). However, many individuals of several species of Heptageniidae (Ephemeroptera), Apsilochorema sutshanum (Trichoptera), and Chironomidae (Diptera) drifted in addition to Baetis after the spray. A large number of young Baetis, which had not been seen in the natural night drift samples, were found drifting due to the insecticide. Natural night drift almost disappeared from the day folowing insecticide spraying. At the second insecticide spraying, conducted 20 days after the first, the number of individuals which drifted during the 24 hr following spraying decreased to only 0.85% of that in the first spraying although changes in insecticide concentration showed a similar pattern. Several species of Ephemeroptera were dominant among the fauna in the studied stream, and the causal relationships of this are discussed.

Impact of a massive crude oil spill on the invertebrate fauna of a Missouri Ozark stream.

The benthic macroinvertebrate fauna of Asher Creek, a 4th order stream with a base flow of 0.03 m(3)/s, was monitored on 11 occasions for 532 days following a 1.5 million liter domestic crude oil spill. Aquatic insects, crustaceans, segmented worms, roundworms, flatworms, snails, freshwater mussels and other benthic organisms in the oil impacted area were reduced to less than 0.1% of expected numbers at the first sampling period 25 days after the spill. Species diversity indices and the number of mayfly and stonefly taxa were less than the minimum values established for unpolluted Missouri streams for 11 months. The initial post-spill community was dominated by Chironomidae (midges), Simuliidae (blackflies) and Oligochaeta (segmented worms). Some species of Plecoptera (stoneflies), Ephemeroptera (mayflies) and Trichoptera (caddisflies) were absent from the fauna for as long as 9 months. The functional feeding groups of scrapers, filterers, gatherers, and predators initially decreased in relative abundance. Predators later increased in response to a rapidly expanding prey base. Shredders did not change in relative abundance throughout the recovery period. Oil was visually present in the stream riffle substrate for 453 days following the spill. Dissolved oxygen, pH and conductivity were not affected. The visible appearance of oil in the stream substrate was a simple predictor of the status of the benthic invertebrate community. Areas protected with surface skimming siphon dams were less severely impacted and recovered more rapidly than areas where the stream substrate was inundated with oil. The most apparent factors controlling the recovery were the total volume of water passing through the contaminated area and the occurrence of scouring flood.

DRIFT OF AQUATIC INSECTS FOLLOWING METHOXYCHLOR TREATMENT OF THE SASKATCHEWAN RIVER SYSTEM

AbstractDrift of aquatic insects was compared at three sites downstream (21, 38, and 107 km) from methoxychlor treatment (0.3 mg. L−1 for 15 min) of the North Saskatchewan River, relative to an upstream untreated site. Species of Diptera (Simuliidae), Ephemeroptera (Baetidae, Heptageniidae, Ephemerellidae, Ametropodidae, Metretopodidae, and Tricorythidae), Plecoptera (Perlodidae and Chloroperlidae), Trichoptera (Hydropsychidae and Hydroptilidae), and Hemiptera (Corixidae) were studied. Drift responses differed depending on species, distance from the injection site, and time after methoxychlor injection. Exposure to methoxychlor initiated catastrophic drift of aquatic insects at all downstream sites. Of 22 species compared before treatment and following methoxychlor injection, post-treatment drift of 17, 21, and 13 species significantly exceeded pre-treatment drift at the km 21, 38, and 107 sites, respectively. Methoxychlor treatment initiated or increased drift of several normally non-drifting species. Similar drift patterns were observed among closely related taxa during the catastrophic phase. For all species studied, comparisons of 24-h drift densities between days preceding and following the catastrophic phase of treatment indicated significant post-treatment drift density increases or decreases at one or more of the downstream sites, but not at the untreated site. Species were classified according to their drift responses to methoxychlor treatment. Factors that may have caused different drift responses among species are discussed.

Trichoptera and ephemeroptera as indicators of environmental changes of the Rhone river at lyons over the last twenty‐five years

AbstractSystematic light trapping was carried out in Lyon on the banks of the Rhǒne river from 1958 to 1982, mainly in the months of June and July. The changes in the type and abundance of the adult Trichoptera and Ephemeroptera species captured over the last 25 years were studied in relation to the perturbations sustained by the river‐and thus by the larval instars.A Correspondence Analysis carried out on the monthly samples defined a first factorial axis which could represent a ‘biological time’ scale characterized by phases of rapid (1959‐1974) or slower (1974‐1982) change of the faunal communities.Five ‘successive’ faunal groups were defined according to the length of historical presence of each of the 88 species along this axis. The most stenoecic species (faunal groups 1, 2 and then 3) seem to disappear and gradually only a small number of species whose ecological requirements are less demanding (faunal groups 4 and 5) subsist.This faunal impoverishment is a consequence of the increasing uniformity of the biotope caused by continuous environmental changes mainly in flow regulation. This has led to reduction in diversity of the substratum and possible food sources. Regular flush‐outs of upstream reservoirs release sediments which clog interstitial spaces over long periods and this effect has been aggravated since 1966 by the bringing into service of a dam situated just downstream from the station.It seems that a new but delicate equilibrium has been reached since 1974; this situation probably corresponds to a less stenoecic biotic community.

Life histories, abundance and distribution of some macroinvertebrates from a South Carolina, USA coastal plain stream

The life histories, densities and distribution patterns of the most abundant macroinvertebrates, exclusive of chironomids and oligochaetes, are reported for a low-gradient, second-order, blackwater stream on the Coastal Plain of South Carolina, USA. Univoltine life histories were found for all species of Coleoptera (Ancyronyx variegata, Macronychus glabratus, Dubiraphia quadrinotata and Hydroporus clypealis) and most species of Ephemeroptera (Eurylophella temporalis, Paraleptophlebia volitans and Hexagenia munda), although the mayfly Stenonema modestum was at least bivoltine. Both univoltinism (Macrostemum carolina and Pycnopsyche luculenta), partial bivoltinism (Nyctiophylax affinis) and complete bivoltinism (Hydropsyche decalda, Cheumatopsyche sp., Phylocentropus placidus and probably Chimarra florida) were found among the Trichoptera. Odonate species were both univoltine (Calopteryx dimidiata, Enallagma divagans and Epitheca cynosura) and semivoltine (Boyeria vinosa, Gomphus lividus and Macromia georgina). The alderfly Sialis aequalis and the isopod Asellus laticaudatus were univoltine, while the blackfly Simulium taxodium produced at least 6 generations per year. Groups of functionally-related species within the orders Odonata, Trichoptera and Coleoptera each exhibited possible temporal and/or spatial segregation.

Food resources and ingestion patterns of insects along a west coast, South Island, river system∗

Abstract Food utilisation by benthic insect larvae at 6 sites along a West Coast, South Island river system (Devils Creek and the Inangahua River) was studied by gut content and stable carbon isotope analyses. At forested and open sites the dominant materials ingested by all species of Ephemeroptera, Plecoptera, and Trichoptera examined were fine detrital particles in the 0.45–75 urn size range. Diatoms and filamentous algae were eaten in varying amounts by some species. Larvae of Deleatidium (Ephemeroptera) and Chironomidae were the numerically dominant prey of the stonefly, Stenoperla prasina at all sites. Stable carbon analyses indicated that most species were dependent largely on carbon of terrestrial origin at forested sites, whereas autochthonous material was used increasingly further down Devils Creek. However, in the large, open Inangahuajliver 13C/12C ratios of insects were similar to those found in the forested tributaries and indicated a return to allochthonous dependence by the fauna. Although...

New Ephemeroptera (Insecta) records from Turkey

Thirty‐five species of Ephemeroptera are recorded from Anatolia, Turkey. Twenty‐four of these species are recorded from Turkey for the first time.

Growth and production of five species of Ephemeroptera larvae from an experimental recirculating stream

SUMMARY. The production and growth of the larvae of five species of Ephemeroptera in an experimental recirculating stream‐channel are described. The most abundant species were Baetis rhodani, which achieved a maximum population density of c. 29,000 m‐2 in August, and Ephemerella ignita which reached a density of c. 13,000 m‐2 in the spring. Three other common speeies, Paraleptophlebia submarginata, Centroptilum luteolum and Caenis rivulorum were present at lower densities (< 1000 m‐2). B. rhodani had five cohorts in a year whilst C. luteolum had two or possibly three. E. ignita, C. rivulorum and P. submarginata were univoltine. Mean speeifie growth rates were calculated for each species, the maximum being 3.26±0.49% length day‐1 for E. ignita (3 April—15 May). Production of each of these five species of Ephemeroptera was calculated giving a total annual production of 10.2 g dry wt m‐2 (computational method).

Modification of benthic insect communities in polluted streams: combined effects of sedimentation and nutrient enrichment

Responses of the benthic insect community of a southern Appalachian trout stream to inorganic sedimentation and nutrient enrichment were monitored over a period of eight months. Entry of pollutants from point sources established differentially polluted zones, allowing an assessment of impacts due to sedimentation alone and in association with elevated nutrient levels. Input of sediment resulted in a significant increase in bed load and decrease of pH at the substrate-water interface (P < 0.05). The zone receiving nutrient runoff from livestock pasture exhibited elevated levels of nitrate and phosphate, but available data indicated such concentrations to be quite low. Species richness, diversity, and total biomass of filter feeding Trichoptera and Diptera, predaceous Plecoptera, and certain Ephemeroptera were significantly reduced in the polluted zones. Inorganic sedimentation, operating indirectly through disruption of feeding and filling of interstitial spaces, was considered to be the primary factor affecting filter feeding taxa. Decomposition of compounds associated with materials in the bed load may depress pH and eliminate acid sensitive species of Plecoptera and Ephemeroptera. Such processes of acidification may be particularly important to Appalachian streams since the pH of regional surface waters is characteristically acidic prior to sedimentation. Accumulation of particles on body surfaces and respiratory structures, perhaps as a function of wax and mucous secretion or surface electrical properties, appears to be the major direct effect of inorganic sedimentation on stream insects. Growths of the filamentous bacterium Sphaerotilus natans were also frequently associated with silted individuals in the zone receiving nutrient addition. Distribution of the bacterium suggested that silted substrates, perhaps as related to the presence of iron compounds, are required for colonization in dilute nutrient solutions. The primary effect of Sphaerotilus colonies appears to be augmentation of particle accumulation through net formation by bacterial filaments. Data indicate that inorganic sedimentation and nutrient addition operate synergistically, eliminating a significantly greater number of taxa than exposure to one pollutant alone.

THE ADULT OF DRUNELLA ALLEGHENIENSIS (EPHEMEROPTERA: EPHEMERELLIDAE) WITH BIOLOGICAL NOTES

AbstractThe adult stage of Drunella allegheniensis (Traver) is described for the first time. Characters separating it from the closely related D. tuberculata (Morgan) are summarized, and the existing taxonomic key to the group is modified to include D. allegheniensis. Other species of Ephemeroptera associated with D. allegheniensis are reported along with observations on its biology.

The growth of some Ephemeropteran nymphs during winter in a North Swedish River

Abstract The growth of the Ephemeroptera species Heptagenia fuscogrisea Retzius, Leptophlebia marginata L. and Ephemerella mucronata Bengtsson was studied from the middle of September 1967 to the middle of May 1968 in the River Ricklean in northern Sweden. Sampling was performed also during periods with ice cover. Growth was estimated from four different body measures and proceeded fairly steady through all the winter for the three species. There were no indications of changed body proportions during the investigation period.

The occurrence ofBaetis rhodani(Ephemeroptera) in the river Lune

Abstract After a long course over a stony substratum, the River Lune, England, runs over flat rock covered with moss. Larvae of four species of Ephemeroptera are abundant in this moss‐covered area from spring to autumn. They overwinter in the egg stage. Baetis rhodani abundant in much of the river at all times of year, is numerous in this stretch in winter but absent from most summer collections. This absence is tentatively attributed to exclusion by the summer species.

Oberservations on the life histories and biology of Ephemeroptera and Plecoptera in northeastern Alberta

Abstract During studies of the environmental effects of oil sands development in northeastern Alberta in 1976–1977, 36 species of Ephemeroptera and 21 of Plecoptera were collected using various techniques. Individuals of 18 mayflies and 17 stoneflies were taken in numbers sufficient to determine their basic life histories and habitat preferences. Among the mayflies, 8 (possibly 10) species exhibited fast seasonal development, 8 slow seasonal, and 2 non‐seasonal. Among the Plecoptera, these patterns were exhibited by 5, 7 and 5 species, respectively. Nymphs of most fast seasonal mayflies developed in pools and silty backwaters, often in association with aquatic macrophytes. Slow seasonal mayflies and most stoneflies were found in riffles, or on bedrock and debris in the Athabasca River. The fauna included a mixture of Eastern, northern and cordilleran species. Eastern species probably reached the Athabasca River drainage via glacial Lake Agassiz.