Behavioral Responses of Drunella coloradensis (Ephemeroptera) Nymphs to Short-Term pH Reductions

1993 ◽  
Vol 50 (12) ◽  
pp. 2692-2697 ◽  
Author(s):  
Christopher M. Pennuto ◽  
Frank deNoyelies Jr.
Keyword(s):  
Acute Stress ◽  
Aquatic Insect ◽  
Behavioral Responses ◽  
Activity Levels ◽  
Stream Channels ◽  
Insect Communities ◽  
Stream Insects ◽  
Community Monitoring ◽  
Behavior Frequency ◽  
Passive Drift

Behavioral responses of Drunella coloradensis nymphs were examined in outdoor experimental stream channels after pH reductions of 1 and 2 pH units below ambient. The severity of pH decline below the ambient of 7.8 influenced the behavior patterns displayed by nymphs. At pH 7.01 (an intermediate pH decline) nymphs sat less frequently and burrowed more than controls. Burrowing behavior frequency returned to control levels and drifting and crawling behaviors increased relative to controls at pH 6.02. Ventilatory behaviors increased with pH decline, but were independent of the severity of acidity increases. These results suggest that individual behaviors may offer a more sensitive indicator of sub-acute stress in aquatic insect communities than population or community monitoring. Behaviors leading to increased activity levels in stream insects may have community-level effects via changes in predator–prey encounter rates or increased susceptibility to passive drift. These potential changes are discussed in reference to monitoring for acidification effects.

scholarly journals Effects of experimental multi-season drought on abundance, richness, and beta diversity patterns in perennially flowing stream insect communities

Hydrobiologia ◽  
2021 ◽  
Author(s):  
P. Saffarinia ◽  
K. E. Anderson ◽  
D. B. Herbst
Keyword(s):  
Beta Diversity ◽  
Aquatic Insect ◽  
Flow Regimes ◽  
Surface Flow ◽  
Insect Community ◽  
Stream Channels ◽  
Insect Communities ◽  
Threshold Response ◽  
Small Streams ◽  
Flow Loss

AbstractFreshwater systems are projected to experience increased hydrologic extremes under climate change. To determine how small streams may be impacted by shifts in flow regimes, we experimentally simulated flow loss over the span of three summers in nine 50 m naturally fed stream channels. The aquatic insect community of these streams was sampled before, during, and after experimental drought treatments as well as following one unforeseen flood event. Abundance, richness, and beta diversity were measured as indicators of biotic effects of altered flow regimes. Abundance declined in proportion to flow loss. In contrast, we observed a threshold response in richness where richness did not decrease except in channels where losses of surface flow occurred and disconnected pools remained. The flood reset this pattern, but communities continued their prior trajectories shortly thereafter. Beta diversity partitions suggested no strong compositional shifts, and that the effect of drought was largely experienced uniformly across taxa until flow cessation. Pools served as a refuge, maintaining stable abundance gradients and higher richness longer than riffles. Upon flow resumption, abundance and richness returned to pre-treatment levels within one year. Our results suggest that many taxa present were resistant to drought conditions until loss in surface flow occurred.

Cave benthic invertebrates in south-eastern Brazil: are there 'key' factors structuring such communities?

2018 ◽  
Vol 69 (11) ◽  
pp. 1762 ◽  
Author(s):  
T. G. Pellegrini ◽  
P. S. Pompeu ◽  
R. L. Ferreira
Keyword(s):  
Aquatic Insect ◽  
Physicochemical Characteristics ◽  
Hydraulic Characteristics ◽  
Key Factors ◽  
Stream Channels ◽  
Insect Communities ◽  
Eastern Brazil ◽  
Physical Features ◽  
Local Variability ◽  
Insect Assemblage

The aim of this study was to determine the effects of microhabitat traits related to water quality and physical features of stream channels (substrate, channel morphology and hydraulic characteristics) on the richness and structure of the aquatic insect assemblage in cave streams. Sampling was conducted in three subterranean streams in Brazil. Aquatic insect richness was significantly and positively related to water depth and the presence of shelters for invertebrates. These shelters are directly related to channel heterogeneity, a factor that determined the surface area of habitats suitable for colonisation, refuges and the amount and variety of nutrients in streams where resources are extremely limited. Furthermore, analyses of community composition revealed that aquatic insect assemblages in each cave were structured by distinct factors (including physicochemical characteristics of the water or hydraulic features of the channel). Together, these findings highlight that different factors are responsible for structuring the assemblages in each cave, which may reflect their local variability, and that silting of cave streams would likely have deleterious effects on aquatic insect communities through reductions in overall habitat heterogeneity.

Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

2019 ◽  
Vol 70 (4) ◽  
pp. 541 ◽  
Author(s):  
Martha J. Zapata ◽  
S. Mažeika P. Sullivan
Keyword(s):  
Aquatic Insects ◽  
High Salinity ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Dispersal Ability ◽  
Insect Community ◽  
Insect Communities ◽  
Low Salinity ◽  
Subtropical Estuary ◽  
Adult Aquatic Insects

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

Trait patterns of aquatic insects across gradients of flow-related factors: a multivariate analysis of Canadian national data

2008 ◽  
Vol 65 (4) ◽  
pp. 670-680 ◽  
Author(s):  
Nelli Horrigan ◽  
Donald J Baird
Keyword(s):  
Dissolved Oxygen ◽  
Large Scale ◽  
Aquatic Insect ◽  
Adult Life ◽  
Taxonomic Composition ◽  
Medium Size ◽  
Insect Communities ◽  
Related Factors ◽  
Adult Life Span ◽  
Consistent Manner

Large-scale comparisons of aquatic bioassessment metrics based on taxonomic composition are currently constrained by the biogeographic limitations of taxon occurrence. The use of species trait patterns offers a possibility to overcome this constraint. We examine the assertion that the trait composition of aquatic insect communities changes in a consistent manner along similar environmental disturbance gradients by evaluating relationships between traits and three flow-related variables (velocity, water temperature, and dissolved oxygen) in 13 independently collected Canadian data sets. Certain trait states such as low crawling rate, common occurrence in drift, short adult life span, erosional rheophily, medium size at maturity, and cold or cool thermal preference were consistently sensitive to all three flow-related factors, velocity in particular, despite biogeographic differences in faunal composition. Trait modalities exhibiting the highest mean correlation with velocity, temperature, and dissolved oxygen were identified, and the potential confounding effect of trait “syndromes” was addressed by restricting the selection of flow-sensitive traits to those with high evolutionary lability. The results of the study provide a basis for the future development of flow bioassessment metrics at the national Canadian scale and potentially at the international scale.

scholarly journals Long-term stress levels are synchronized in dogs and their owners

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ann-Sofie Sundman ◽  
Enya Van Poucke ◽  
Ann-Charlotte Svensson Holm ◽  
Åshild Faresjö ◽  
Elvar Theodorsson ◽  
...  
Keyword(s):  
Personality Traits ◽  
Acute Stress ◽  
Seasonal Effect ◽  
Activity Levels ◽  
Stress Levels ◽  
Interspecific Synchronization ◽  
General Physical ◽  
First Time ◽  
Previous Summer

Abstract This study reveals, for the first time, an interspecific synchronization in long-term stress levels. Previously, acute stress, has been shown to be highly contagious both among humans and between individuals of other species. Here, long-term stress synchronization in dogs and their owners was investigated. We studied 58 dog-human dyads and analyzed their hair cortisol concentrations (HCC) at two separate occasions, reflecting levels during previous summer and winter months. The personality traits of both dogs and their owners were determined through owner-completed Dog Personality Questionnaire (DPQ) and human Big Five Inventory (BFI) surveys. In addition, the dogs’ activity levels were continuously monitored with a remote cloud-based activity collar for one week. Shetland sheepdogs (N = 33) and border collies (N = 25), balanced for sex, participated, and both pet dogs and actively competing dogs (agility and obedience) were included to represent different lifestyles. The results showed significant interspecies correlations in long-term stress where human HCC from both summer and winter samplings correlated strongly with dog HCC (summer: N = 57, χ2 = 23.697, P < 0.001, β = 0.235; winter: N = 55, χ2 = 13.796, P < 0.001, β = 0.027). Interestingly, the dogs’ activity levels did not affect HCC, nor did the amount of training sessions per week, showing that the HCC levels were not related to general physical activity. Additionally, there was a seasonal effect in HCC. However, although dogs’ personalities had little effects on their HCC, the human personality traits neuroticism, conscientiousness, and openness significantly affected dog HCC. Hence, we suggest that dogs, to a great extent, mirror the stress level of their owners.

Young Burned Children: The Course of Acute Stress and Physiological and Behavioral Responses

2006 ◽  
Vol 163 (6) ◽  
pp. 1084-1090 ◽  
Author(s):  
Frederick J. Stoddard ◽  
Heidi Ronfeldt ◽  
Jerome Kagan ◽  
Jennifer E. Drake ◽  
Nancy Snidman ◽  
...  
Keyword(s):  
Acute Stress ◽  
Behavioral Responses

Phytotelmata: Terrestrial Plants as Hosts for Aquatic Insect Communities

10.2307/4551 ◽  
1984 ◽  
Vol 53 (2) ◽  
pp. 698 ◽  
Author(s):  
B. J. Finlay ◽  
J. H. Frank ◽  
L. P. Lounibos
Keyword(s):  
Aquatic Insect ◽  
Terrestrial Plants ◽  
Insect Communities
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