База резюме и ссылок по экологии бентоса

Поденки: 3 вида, Альпы

Title: Abundance, Growth and Production of 3 Mayfly Species (Ephemeroptera, Insecta) from the Swiss Pre-Alps

Source: ARCHIV FUR HYDROBIOLOGIE 1990, Vol 120, Iss 2, pp 211-228

Addresses:

UNIV-FRIBOURG, INST ZOOL, DEPT ENTOMOL, CH-1700 FRIBOURG,

SWITZERLAND

A comparative study of three common mayfly species from the

Swiss Prealps was carried out at two stations. Both localities

exhibited quite similar temperature regimes but differences were

recorded in the structure of substrate and in chemical

characteristics of water. The first station was situated near a

small lake and was influenced by the release of allochthonous

nutrients due to local human activities. Significant

differences in abundance between the two populations were

recorded for Rhithrogena semicolorata (CURTIS) and

Habroleptoides confusa SARTORI & JACOB but not for Ephemerella

ignita PODA. These density differences were attributed mainly

to the geomorphological nature of the substrate. Estimations of

mean daily productions per m2 for the three species were always

higher at station near the lake and could be related to the high

nutrients content of the station. The spatial distributions,

the elimination rates and the growth rates of the species were

not significantly different in the two populations.

Поденки: дрифт личинок.

Volume 45 Issue 1 Page 33 - September 2000

Nocturnal drift of mayfly nymphs as a post-contact antipredator mechanism

Arto Huhta* Timo Muotka Pertti Tikkanen*

1.The predominantly nocturnal constrained drift of stream invertebrates is

commonly regarded as a behaviour that avoids encounters with visually foraging

fish in the water column. The alternative explanation, that drift peaks are caused by

bottom-feeding, nocturnal predators, has rarely been tested.

2.We examined these hypotheses by collecting invertebrate drift in five streams in

northern Finland: one with brown trout (Salmotrutta, a drift-feeding fish), one with

alpine bullhead (Cottuspoecilopus, a benthic fish), one with both species, and two

fishless streams.

3.Drift by Baetis mayflies was aperiodic or slightly diurnal in both fishless streams

on all sampling occasions. In contrast, drift was nocturnal in streams with trout and,

to a lesser extent, in the stream with bullhead. Non-dipteran prey drifted mainly

nocturnally in all streams with fish, whereas Diptera larvae were less responsive to

the presence of fish.

4.In laboratory experiments, bullheads were night-active, causing a much higher

frequency of drift by touching Baetis at night than during the day. Thus, increased

nocturnal drift may serve to avoid both visual predators (a pre-contact response)

and benthic fish (a post-contact response). In streams with bottom-feeding fish,

nocturnal drift should be caused by increased drift by night rather than by reduced

drift by day.

Поденки

FRESHWATER BIOLOGY 1995, Vol 34, Iss 2, pp 297-302

Abstract:

1. The spatial niche shifts of the nymphs of two mayfly

species (Rhithrogena semicolorata and Ecdyonurus sp. gr.

venosus) in relation to their growth were investigated in two

lowland springs of northern Italy where they are dominant

species.

species revealed a canonical trend related to season and bottom

roughness.

3. Larger nymphs of both species colonized rougher

substrata. Differences between species in the roughness of areas

colonized by small nymphs, which were very numerous, may have

been due to competition for space.

Поденки Baetidae: распределение.

ARCHIV FUR HYDROBIOLOGIE 1994, Vol 131, Iss 4, pp 465-476

В р.Ниандан очень высокое разнообразие Baetidae - собрано 22 вида, из которых 11 обильны в каждой пробе. Обсуждается сосуществование такого количества болизких видов в ограниченном местообитании. Многие виды обнаружили различия в улавливаемости разными методами сбора (бентометром или сбором с поверхности камней). Биотопные предпочтения варьируют по степени заиления и скорости течения, но сильно перекрываются. На каменистых субстратах плотность поденок была выше на прямых стеблях Podostemaceae. Во время периода съемок (с февраля по апрель) плотность 2 видов (Afroptilum christinae, Dicentroptilum papillosum) уменьшалась, а плотность Pseudopannota bertrandi и Pseudopannota muganinani возрастала.

Abstract:

The specific richness of Baetidae (Insecta: Ephemeroptera) was very high at a station on the River Niandan (Guinea): 22 species were collected, of which 11 were abundant in at least one microhabitat. The coexistence of numerous morphologically similar species within a limited area is discussed. Most species showed a difference in vulnerability according to the sampling method (benthometre or sampling the lower surface of stones). Biotope preferences were varied (according to the degree of silting and the velocity of the current) and overlapped strongly. On rocky substrates, larval densities were higher in the erect stems of Podostemaceae. During the sampling period (February to April), the larval densities of Afroptilum christinae and Dicentroptilum papillosum decreased while those of Pseudopannota bertrandi and Pseudopannota muganinani increased.

Поденки: дрифт личинок Baetis.

Title: Stable Isotopes Resolve the Drift Paradox for Baetis

Mayflies in an Arctic River

Source: ECOLOGY

1993, Vol 74, Iss 8, pp 2315-2325

UNIV-MINNESOTA, DEPT BIOL, DULUTH, MN 55812, USA

Abstract:

The colonization cycle hypothesis states that stream

ecosystems would become depleted of insects if flying adults did

not compensate for drifting immatures. Using long-term drift and

benthic abundance data, we show that a Baetis mayfly nymph

population moves downstream during development in the Kuparuk

River in arctic Alaska. Baetis relative benthic abundance

decreased from early to late season in an upstream unfertilized

river section, while simultaneously increasing in the downstream

fertilized section. Baetis nymphs drifted significantly more in

the upstream unfertilized section, compared to the downstream

fertilized section where food was more abundant. Approximately

one-third to one-half of the nymph population drifted at least

2.1 km downstream during the arctic summer. A stable isotope

tracer experiment and mathematical models show that about one-

third to one-half of the adult Baetis population flew 1.6-1.9 km

upstream from where they emerged.

These results provide a quantitative test of the

colonization cycle for the dominant grazer/collector in the

Kuparuk River. Quantifying the colonization cycle is essential

to understanding stream ecosystem function because offspring of

downstream insects are needed for nutrient cycling and carbon

processing upstream. Since downstream drift and upstream flight

are important components in recovery of streams from

disturbances, our results provide a quantitative method for

predicting recolonization rates from downstream, essential to

estimating recovery.

Поденки: вертикальные миграции.

Volume 24 Issue 4 Page 443-449 - November 1999

TimO. Muotka, ArtO. Huhta* and Pertti Tikkanen*

1. The diel foraging periodicities of two grazing mayfly (Ephemeroptera) nymphs, Heptagenia dalecarlica and Baetis rhodani, under variable fish (European minnow) predation risk were examined in a series of laboratory experiments.

2. Heptagenia dalecarlica were almost exclusively nocturnal in their use of feeding areas on stone tops. There was a sharp increase in the proportion of nymphs out of refuge at nightfall, both in the control and fish-odour treatments. In a treatment with freely moving fish, H. dalecarlica decreased their activity during both the day and night. In feeding trials with three freely foraging minnows, nymphs were completely safe when they had access to refuges beneath stones, whereas almost half the nymphs were consumed when no refuges were available.

3. Baetis rhodani nymphs reduced their use of stone tops when exposed to four caged minnows or a freely moving fish, but this occurred both day and night. In feeding trials, B. rhodani were captured only while in the water column, and their mortality risk was independent of refuge availability.

4. It is suggested that because H. dalecarlica lack efficient post-encounter defences, they must rely on pre-encounter mechanisms to reduce the threat of fish predation. It appears that in order to dwell sympatrically with fish, H. dalecarlica have evolved a coexistence by hiding strategy. In contrast, Baetis are vulnerable to fish attacks only if they enter drift in daylight, and are thus able to remain on stone tops both during the day and at night.

Поденки: распределение. Кислые водотоки, Канада.

Authors: Giberson-DJ Mackay-RJ

Life-History and Distribution of Mayflies (Ephemeroptera) in Some Acid Streams in South Central Ontario, Canada

Source: CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE

1991, Vol 69, Iss 4, pp 899-910

Abstract:

Life histories and distribution of mayflies

(Insecta:Ephemeroptera) were investigated in 11 streams in south

central Ontario that ranged from highly acidic to circumneutral.

At least 29 mayfly species were recorded from the streams, with

16 common enough for life history analysis. Mayfly distribution

and diversity were correlated with pH regime and stream size.

No mayflies were found in the smallest, most acid stream, and

numbers of mayfly species and their relative abundances

generally increased with both increasing stream size and stream

pH. Incorporation of life cycle information with distributional

data enabled us to determine the precise stream-water pH range

encountered by different mayfly life stages in the study

streams. Generally, during the period of greatest acid stress

in the streams (pH depressions associated with spring snowmelt)

the mayflies were present in large or dormant stages, which are

believed to be more tolerant of lowered pH.

Поденки: реакция на хищников. Покров темноты.

Authors: Culp-JM Glozier-NE Scrimgeour-GJ

Уменьшение риска выедания под покровом темноты: реакция поденок на выедание рыбами.

Title: Reduction of Predation Risk Under the Cover of Darkness - Avoidance Responses of Mayfly Larvae to a Benthic Fish

Source: OECOLOGIA 1991, Vol 86, Iss 2, pp 163-169

Mayfly larvae of Paraleptophlebia heteronea (McDunnough)

had two antipredator responses to a nocturnal fish predator

(Rhinichthys cataractae (Valenciennes)): flight into the drift

and retreat into interstitial crevices. Drift rates of

Paraleptophelbia abruptly increased by 30 fold when fish were

actively foraging in the laboratory streams but, even before

fish were removed, drift began returning to control levels

because larvae settled to the substrate and moved to areas of

low risk beneath stones. This drifting response was used as an

immediate escape behaviour which likely decreases risk of

capture from predators which forage actively at night.

Surprisingly, drift most often occurred before contact between

predator and prey, and we suggest that in darkness this mayfly

may use hydrodynamic pressure waves for predator detection,

rather than chemical cues, since fish forage in an upstream

direction. Although drifting may represent a cost to mayfly

larvae in terms of relocation to a new foraging area with

unknown food resources, the immediate mortality risk probably

out-weighs the importance of staying within a profitable food

patch because larvae can survive starvation for at least 2 d.

In addition to drifting, mayflies retreated from upper, exposed

substrate surfaces to concealed interstitial crevices

immediately after a predator encounter, or subsequent to

resettlement on the substrate after predator-induced drift. A

latency period was associated with this response and mayflies

remained in these concealed locations for at least 3 h after

dace foraging ceased. Because this mayfly feeds at night and

food levels are significantly lower in field refugia under

stones, relative to exposed stone surfaces, predator avoidance

activity may limit foraging time and, ultimately, reduce the

food intake of this stream mayfly.

Поденки: разделение местообитаний.

Authors: Hearnden-MN Pearson-RG

Title: Habitat Partitioning Among the Mayfly Species (Ephemeroptera) of Yuccabine Creek, a Tropical Australian Stream

Source: OECOLOGIA 1991, Vol 87, Iss 1, pp 91-101

This study examines the distributions among microhabitats

of 12 detritivorous species of mayfly in Yuccabine Creek, an

upland tropical rainforest stream. Analysis of data from

regular benthic sampling and from in situ experiments using

implanted substrata showed that although all species occurred in

all the microhabitats examined, different species had

significantly different peaks of abundance in different

microhabitats, leading to distinct partitioning of the available

habitat. The observed patterns of distribution were closely

associated with the distribution of fine detritus deposits

(FPOM). In the absence of FPOM in fast-flowing regions of the

stream, leaf litter was the prime determinant of species

distribution. Current velocity and substratum particle size

influenced the distribution of the detritus and leaf litter.

Abundance of mayflies was greatest in the pool habitat for all

except two of the species.

Поденки: дрифт и его причины.

Authors: Poff-NL Decino-RD Ward-JV

Title: Size-Dependent Drift Responses of Mayflies to

Experimental Hydrologic Variation - Active Predator

Avoidance or Passive Hydrodynamic Displacement

Source: OECOLOGIA 1991, Vol 88, Iss 4, pp 577-586

Larger nymphs within aquatic insect taxa have been

frequently observed to be transported downstream in the stream

drift only at night. Others have hypothesized this pattern

results primarily from large nymphs' behavioural avoidance of

entering drift during daylight, when size-selective, visually-

feeding fish predators are most active. This hypothesis assumes

that animals can actively control their entry into the drift,

which may not be the case under all flow conditions. We

experimentally induced streamflow increases and decreases in

adjacent riffles in a hydrologically-stable stream during the

daytime to examine whether changes in diel patterns of drift

abundance and size-distribution of mayflies were consistent with

the hypothesis of active avoidance of diurnal drift. We assessed

the likelihood of active vs. passive mechanisms of diurnal drift

entry and transport for four taxa that differ with respect to

body size, morpho-behavioural attributes, microhabitat use, and

general propensity to drift. In each of three seasons, diurnal

and nocturnal drift samples were collected in three riffles over

two diel cycles. Background drift patterns were established on

the first day (no flow manipulation). Six h before sunset on the

second day, flow was experimentally increased in one riffle,

decreased in the second, and not altered in the third (control).

Between-day differences in diurnal and nocturnal drift rate and

size composition were then compared among the treatment and

reference riffles. Responses of two taxa were consistent with

active control over drift entry, transport, or both. For Baetis

spp., drift-prone mayflies typically preyed upon by fish,

diurnal drift rates immediately increased following both flow

reduction and flow elevation in all seasons, but only small

individuals comprised the drift. Drift by large individuals was

delayed until night-time. Epeorus longimanus also exhibited

significant increases in drift rates following flow reduction

and elevation, but responses of this large-bodied species were

restricted to nighttime. Drift responses for these two taxa were

largely independent of direction of hydrologic change. thus

indicating a strong behavioural control over drift. By contrast,

numbers and sizes of drifting Paraleptophlebia heteronea and

Ephemerella infrequens depended strongly on direction of flow

change. Drift rates for both species generally declined after

flow reduction and increased after flow elevation. Moreover,

after flow elevation, larger individuals often drifted

diurnally, a finding consistent with expectations under a

passive hydrodynamic model. These experiments indicate that size-

dependent mayfly drift reflects not only presumed risk from

visual fish predators, but also functional attributes of species

such as morphology, behaviour, and microhabitat affiliation,

which influence aspects of drift entry and transport under

variable hydrologic conditions.

Поденки: Caenis

Gonzalez-JM Basaguren-A Pozo-J

Life-History and Production of Caenis-Luctuosa (Burmeister) (Ephemeroptera, Caenidae) in 2 Nearby Reaches Along a Small Stream

Source: HYDROBIOLOGIA 2001, Vol 452, Iss 1-3, pp 209-215

Population dynamics and production of C. luctuosa were

compared in two reaches of the Aguera stream (northern Spain).

This species showed univoltine winter life history in both

sites. However, the start of the recruitment period, and the

cohort production interval differed in 1 month between reaches.

Secondary production of C. luctuosa ranged from 76 mg m(-2)

year(-1) (upper site) to 93 mg m(-2) year(-1) (lower site).

Although annual production seemed to be mainly influenced by the

biomass found at each site, changes in life history may have

also been important. The need to have accurate information about

life history of the analysed species at the study sites when

assessing secondary production is highlighted.

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