Population divergence in aggregation and sheltering behaviour in surface and cave-adapted Asellus aquaticus (Crustacea: Isopoda)

Aggregation (gathering together) and sheltering (hiding in cover) are basic behaviours that might reduce the risk of predation. However, both behaviours have costs, like increased competition over resources and high prevalence of contact-spread parasites (aggregation) or lost opportunities for foraging and mating (sheltering). Therefore, adaptive variation in these behaviours is expected between populations with varying levels of predation risk. We compared aggregation and sheltering in surface- (various predators) and cave-adapted (no predator) populations of the Isopod Asellus aquaticus in a common garden experiment. Since the cave environment is constantly dark, we also tested for population variation in light-induced behavioural plasticity by applying light treatments. Variation in sheltering was explained by habitat type: cave individuals sheltered less than surface individuals. We found high between-population variation in aggregation with or without shelters and their light-induced plasticity, which were unexplained by habitat type. Cave individuals habituated (decreased sheltering), while surface individuals showed sensitization (increased sheltering). We suggest that population variation in sheltering is driven by predation, while variation in aggregation must be driven by other, unaccounted environmental factors, similarly to light-induced behavioural plasticity. Based on habituation/sensitization patterns, we suggest that predation-adapted populations are more sensitive to disturbance related to standard laboratory procedures.

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Do changes in reef habitats influence relative predation risk on the juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875)?

Crustaceana ◽

10.1163/15685403-00003447 ◽

2015 ◽

Vol 88 (7-8) ◽

pp. 839-856 ◽

Cited By ~ 4

Author(s):

J. Hesse ◽

J. A. Stanley ◽

A. G. Jeffs

Keyword(s):

Predation Risk ◽

Spatial Scales ◽

Spiny Lobster ◽

Habitat Type ◽

Small Spatial Scale ◽

Important Species ◽

Early Juvenile ◽

Risk Of Predation ◽

Jasus Edwardsii ◽

Commercially Important

Kelp habitats are in decline in many temperate coastal regions of the world due to climate change and expansion of populations of grazing urchins. The loss of kelp habitat may influence the vulnerability to predators of the juveniles of commercially important species. In this study relative predation rates for kelp versus barren reef habitat were measured for early juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875), on the northeastern coast of New Zealand using tethering methods. Variation in assemblages of predators over small spatial scales appeared to be more important for determining the relative predation of lobsters, regardless of habitat type. Therefore, the assessment of relative predation risk to early juvenile lobsters between kelp and barren habitats will require more extensive sampling at a small spatial scale, as well as a specific focus on sampling during crepuscular and nocturnal periods when these lobsters are most at risk of predation.

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Seasonal Habitat Use by Nubian Ibex (Capra Nubiana) Evaluated with Behavioral Indicators

Israel Journal of Ecology and Evolution ◽

10.1560/ijee.57.3.223 ◽

2011 ◽

Vol 57 (3) ◽

pp. 223-246 ◽

Cited By ~ 10

Author(s):

Solomon A. Tadesse ◽

Burt P. Kotler

Keyword(s):

Group Size ◽

Age Structure ◽

Time Allocation ◽

Environmental Variables ◽

Time Budget ◽

Habitat Type ◽

Time Budgets ◽

Behavioral Models ◽

Risk Of Predation ◽

Focal Observation

Nubian ibex (Capra nubiana) prefer steep terrain in their landscape to reduce risks of predation and human nuisance disturbances. They also use vigilance and time allocation to manage risk of predation. We studied time budgets and habitat selection of Nubian ibex to: (1) identify the habitat variables to which Nubian ibex were behaviorally responsive; (2) investigate how time budget responses of Nubian ibex were related to season, slope condition, group size, and sex-age structure; and (3) develop behavioral-based models that account for the variations in the behaviors of Nubian ibex across the landscape and seasons.To quantify time budgets, we took regular field observations on focal individuals of Nubian ibex classified according to their habitat, group size, sex, and age. For each focal observation, we quantified environmental variables that were thought to influence the behavioral responses of ibex. Then, we developed behavioral models by correlating the proportion of behaviors measured in focal animal observations to the influential environmental variables. The behaviors of Nubian ibex significantly varied with sex and age structure, season, habitat type, and slope conditions. Adult females are more vigilant than adult male ibex, especially in the spring. This correlates with breeding and nursing activities. Based on the characteristics of the habitat, ibex behave to minimize risks of predation and human nuisance disturbances while maximizing their food intake.

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The coevolution of adult body mass and excretion rate between genetically size-divergent brook trout populations

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2017-0508 ◽

2019 ◽

Vol 76 (3) ◽

pp. 438-446 ◽

Cited By ~ 1

Author(s):

Stéphanie Guernon ◽

Matthew C. Yates ◽

Dylan J. Fraser ◽

Alison M. Derry

Keyword(s):

Body Mass ◽

Brook Trout ◽

Excretion Rate ◽

Common Garden ◽

Population Divergence ◽

Mass Energy ◽

Maternal Factors ◽

Mass Distributions ◽

Adult Body Mass ◽

Adult Body

We tested if there was a difference in mass-specific excretion rate between two genetically size-divergent brook trout (Salvelinus fontinalis) populations that can be accounted for by genetic/maternal factors. We conducted laboratory-based common garden experimentation using F1 generation fish, with five to seven families per population at two ages (0.5 year juveniles and 1.5 years adults). We found that genetic/maternal differences in excretion rate on a per gram basis coevolve with genetic divergence in adult body mass between the populations. However, this coevolution has also resulted in no net difference in excretion rate between populations when differences in adult body mass were accounted for. Uncertainty in census estimates and variation in body mass distributions created substantial variation in extrapolated whole-population excretion estimates. No other studies to our knowledge have tested for genetic/maternal divergence in excretion rate between genetically size-divergent fish populations. Genetically based population divergence in body mass, energy allocation in reproduction, and mass-specific excretion rate in the brook trout was likely a result of selection associated with differences in the availability of overwintering habitat between streams.

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Testing Whether Camera Presence Influences Habitat Specific Predation Pressure on Artificial Shorebird Nests in the Arctic

ARCTIC ◽

10.14430/arctic72057 ◽

2021 ◽

Vol 74 (1) ◽

pp. 22-29

Author(s):

Kevin G. Young ◽

Lisa V. Kennedy ◽

Paul A. Smith ◽

Erica Nol

Keyword(s):

Predation Risk ◽

Proportional Hazards Model ◽

Habitat Type ◽

Cox Proportional Hazards Model ◽

The Arctic ◽

Arctic Fox ◽

Artificial Nests ◽

Predator Species ◽

Risk Of Predation ◽

The Impact

When monitoring the breeding ecology of birds, the causes and times of nest failure can be difficult to determine. Cameras placed near nests allow for accurate monitoring of nest fate, but their presence may increase the risk of predation by attracting predators, leading to biased results. The relative influence of cameras on nest predation risk may also depend on habitat because predator numbers or behaviour can change in response to the availability or accessibility of nests. We evaluated the impact of camera presence on the predation rate of artificial nests placed within mesic tundra habitats used by Arctic-breeding shorebirds. We deployed 94 artificial nests, half with cameras and half without, during the shorebird-nesting season of 2015 in the East Bay Migratory Bird Sanctuary, Nunavut. Artificial nests were distributed evenly across sedge meadow and supratidal habitats typically used by nesting shorebirds. We used the Cox proportional hazards model to assess differential nest survival in relation to camera presence, habitat type, placement date, and all potential interactions. Artificial nests with cameras did not experience higher predation risk than those without cameras. Predation risk of artificial nests was related to an interaction between habitat type and placement date. Nests deployed in sedge meadows and in supratidal habitats later in the season were subject to a higher risk of predation than those deployed in supratidal habitats early in the season. These differences in predation risk are likely driven by the foraging behaviour of Arctic fox (Vulpes lagopus), a species that accounted for 81% of observed predation events in this study. Arctic fox prey primarily on Arvicoline prey and goose eggs at this site and take shorebird nests opportunistically, perhaps more often later in the season when their preferred prey becomes scarcer. This study demonstrates that, at this site, cameras used for nest monitoring do not influence predation risk. Evaluating the impact of cameras on predation risk is critical prior to their use, as individual study areas may differ in terms of predator species and behaviour.

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Climate-driven divergent selection in a foundation tree species: QST-FST evidence from multiple common gardens

10.22541/au.161273878.82956729/v1 ◽

2021 ◽

Author(s):

Hillary Cooper ◽

Gerard Allan ◽

Lela Andrews ◽

Rebecca Best ◽

Kevin Grady ◽

...

Keyword(s):

Local Adaptation ◽

Tree Species ◽

Divergent Selection ◽

Population Variation ◽

Population Divergence ◽

Phenotypic Traits ◽

Local Conditions ◽

Basal Diameter ◽

Common Gardens ◽

Fremont Cottonwood

Widespread tree species span large climatic gradients that often lead to high levels of local adaptation and phenotypic divergence across their range. To evaluate the relative roles of selection and drift in driving divergence in phenotypic traits, we compared molecular and quantitative genetic variation in Populus fremontii (Fremont cottonwood), using data from > 9000 SNPs and genotypes from 16 populations reciprocally planted in three common gardens that span the species’ climatic range. We present three major findings: 1) There is significant within- and among-population variation in functional traits expressed in each of the common gardens. 2) There is evidence from all three gardens that population divergence in leaf phenology and specific leaf area has been driven by divergent selection (QST > FST). In contrast, QST-FST comparisons for performance traits like height and basal diameter were highly dependent on growing environment, indicating divergent, stabilizing, or no selection across the three gardens. We show this is likely due to local adaptation of source populations to contrasting growing environments. 3) Climate is a primary selective force driving trait divergence, where the traits showing the strongest correlations with a genotype’s provenance climate also had the highest QST values. We conclude that climatic gradients have contributed to significant phenotypic differences and local adaptation in Fremont cottonwood. These results are important because as climate is changing much more rapidly, traits such as phenology that are finely tuned to local conditions may now be subject to intense selection or quickly become maladaptive.

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Occurrence of Methicillin-Resistant Staphylococcus aureus in Ready-to-Eat Raw Fish from Japanese Cuisine Restaurants in Salvador, Brazil

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-375 ◽

2020 ◽

Vol 83 (6) ◽

pp. 991-995

Author(s):

JOELZA SILVA CARVALHO ◽

ANTENOR FERREIRA LEAL NETO ◽

ISABELA MACIEL MELO ◽

LUANA MILEN VARJÃO ◽

CARLOS ALBERTO DAS NEVES ANDRADE ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistant ◽

Antimicrobial Resistance Profile ◽

Fish Samples ◽

High Prevalence ◽

Disk Diffusion Assay ◽

Laboratory Procedures ◽

Mrsa Strains

ABSTRACT The presence of methicillin-resistant Staphylococcus aureus (MRSA) strains in food products is a major issue for food safety. The present study was conducted to evaluate the occurrence and antimicrobial resistance profile of S. aureus, focusing on MRSA isolates, in ready-to-eat sashimi from Japanese restaurants in Salvador, Brazil. A total of 127 sashimi samples were collected directly from the take-out service in 16 restaurants. The staphylococcal isolates were identified morphologically and biochemically with standard laboratory procedures. S. aureus isolates were tested with a disk diffusion assay against seven antibiotics, and the cefoxitin and oxacillin were used to identify MRSA strains. Isolates with the MRSA phenotype were confirmed with a PCR assay. S. aureus was found in 73% of the sashimi samples, including sashimi from tuna (75.5% of samples) and salmon (72.5% of samples). Among those positive samples, 37% were contaminated with MRSA strains, found among 38.8% of salmon sashimi and 34.0% of tuna sashimi. Penicillin resistance was the most common type of antimicrobial resistance, found in 65.5% of the sashimi samples, followed by resistance to tetracycline (22.5%), erythromycin (16.0%), and ciprofloxacin (3.2%). Only two S. aureus isolates collected from different fish samples and restaurants had presumed resistance to vancomycin. The high prevalence of S. aureus and MRSA in these sashimi samples indicates a potential risk for foodborne disease, especially MRSA, spreading in the community. HIGHLIGHTS

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Perkinsus beihaiensis (Perkinsozoa) in oysters of Bahia State, Brazil

Brazilian Journal of Biology ◽

10.1590/1519-6984.07016 ◽

2017 ◽

Vol 78 (2) ◽

pp. 289-295 ◽

Cited By ~ 1

Author(s):

M. S. A. Luz ◽

F. S. Carvalho ◽

H. C. Oliveira ◽

G. Boehs

Keyword(s):

Infection Intensity ◽

Severe Infection ◽

Gastric Epithelium ◽

Genetic Identification ◽

Chain Reaction ◽

High Prevalence ◽

Laboratory Procedures ◽

Polymerase Chain ◽

Crassostrea Rhizophorae ◽

Macroscopic Analysis

Abstract This study reports the pathogen Perkinsus beihaiensis in oysters of the genus Crassostrea on the coast of the State of Bahia (Brazil), its prevalence, infection intensity and correlation with salinity. Oysters (n = 240) were collected between October and December 2014 at eight sampling stations between latitudes 13°55'S and 15°42'S. The laboratory procedures included macroscopic analysis, histology, culture in Ray's fluid thioglycollate medium (RFTM), Polymerase Chain Reaction (PCR) and DNA sequencing. PCR and sequencing have been used for the genetic identification of oysters as well. Two species of oysters have been identified: Crassostrea rhizophorae and C. brasiliana. In both oyster species P. beihaiensis was the only Perkinsus species detected. In C. rhizophorae, the average prevalence was 82.8% by histology and 65.2% by RFTM. In C. brasiliana, the prevalences were 70.5% and 35.7%, respectively. The higher prevalence of P. beihaiensis in C. rhizophorae was probably influenced by salinity, with which was positively correlated (r> 0.8). In both oysters, P. beihaiensis was located mainly in the gastric epithelium. The infection was generally mild or moderate, without apparent harm to the hosts, but in cases of severe infection, there was hemocytical reaction and tissue disorganization. The generally high prevalence in the region suggests that oysters should be monitored with respect to this pathogen, especially in growing areas.

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Contrasted habitats and individual plasticity drive the fine scale movements of juvenile green turtles in coastal ecosystems

Movement Ecology ◽

10.1186/s40462-019-0184-2 ◽

2020 ◽

Vol 8 (1) ◽

Cited By ~ 1

Author(s):

Philippine Chambault ◽

Mayeul Dalleau ◽

Jean-Benoît Nicet ◽

Pascal Mouquet ◽

Katia Ballorain ◽

...

Keyword(s):

Indian Ocean ◽

Habitat Type ◽

West Indian ◽

Behavioural Plasticity ◽

The South ◽

Green Turtles ◽

South West Indian Ocean ◽

South West ◽

West Indian Ocean ◽

Feeding Grounds

Abstract Background A strong behavioural plasticity is commonly evidenced in the movements of marine megafauna species, and it might be related to an adaptation to local conditions of the habitat. One way to investigate such behavioural plasticity is to satellite track a large number of individuals from contrasting foraging grounds, but despite recent advances in satellite telemetry techniques, such studies are still very limited in sea turtles. Methods From 2010 to 2018, 49 juvenile green turtles were satellite tracked from five contrasting feeding grounds located in the South-West Indian Ocean in order to (1) assess the diel patterns in their movements, (2) investigate the inter-individual and inter-site variability, and (3) explore the drivers of their daily movements using both static (habitat type and bathymetry) and dynamic variables (daily and tidal cycles). Results Despite similarities observed in four feeding grounds (a diel pattern with a decreased distance to shore and smaller home ranges at night), contrasted habitats (e.g. mangrove, reef flat, fore-reef, terrace) associated with different resources (coral, seagrass, algae) were used in each island. Conclusions Juvenile green turtles in the South-West Indian Ocean show different responses to contrasting environmental conditions - both natural (habitat type and tidal cycle) and anthropogenic (urbanised vs. uninhabited island) demonstrating the ability to adapt to modification of habitat.

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Plasticity of parental care under the risk of predation: how much should parents reduce care?

Biology Letters ◽

10.1098/rsbl.2013.0154 ◽

2013 ◽

Vol 9 (4) ◽

pp. 20130154 ◽

Cited By ~ 67

Author(s):

Cameron K. Ghalambor ◽

Susana I. Peluc ◽

Thomas E. Martin

Keyword(s):

Parental Care ◽

Predation Risk ◽

Perceived Risk ◽

Nest Predation ◽

Behavioural Plasticity ◽

Risk Of Predation ◽

Theoretical Predictions ◽

The Mean ◽

Parental Provisioning ◽

Nest Predator

Predation can be an important agent of natural selection shaping parental care behaviours, and can also favour behavioural plasticity. Parent birds often decrease the rate that they visit the nest to provision offspring when perceived risk is high. Yet, the plasticity of such responses may differ among species as a function of either their relative risk of predation, or the mean rate of provisioning. Here, we report parental provisioning responses to experimental increases in the perceived risk of predation. We tested responses of 10 species of bird in north temperate Arizona and subtropical Argentina that differed in their ambient risk of predation. All species decreased provisioning rates in response to the nest predator but not to a control. However, provisioning rates decreased more in species that had greater ambient risk of predation on natural nests. These results support theoretical predictions that the extent of plasticity of a trait that is sensitive to nest predation risk should vary among species in accordance with predation risk.

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Full-genome evolutionary histories of selfing, splitting and selection in Caenorhabditis

10.1101/011502 ◽

2014 ◽

Author(s):

Cristel G. Thomas ◽

Wei Wang ◽

Richard Jovelin ◽

Rajarshi Ghosh ◽

Tatiana Lomasko ◽

...

Keyword(s):

Population History ◽

Population Variation ◽

Population Divergence ◽

Genomic Context ◽

Size Change ◽

High Coverage ◽

C Elegans ◽

Developmental Evolution ◽

History Of ◽

Rare Gene

The nematode Caenorhabditis briggsae is a model for comparative developmental evolution with C. elegans. Worldwide collections of C. briggsae have implicated an intriguing history of divergence among genetic groups separated by latitude, or by restricted geography, that is being exploited to dissect the genetic basis to adaptive evolution and reproductive incompatibility. And yet, the genomic scope and timing of population divergence is unclear. We performed high-coverage whole-genome sequencing of 37 wild isolates of the nematode C. briggsae and applied a pairwise sequentially Markovian coalescent (PSMC) model to 703 combinations of genomic haplotypes to draw inferences about population history, the genomic scope of natural selection, and to compare with 40 wild isolates of C. elegans. We estimate that a diaspora of at least 6 distinct C. briggsae lineages separated from one another approximately 200 thousand generations ago, including the ???Temperate??? and ???Tropical??? phylogeographic groups that dominate most samples from around the world. Moreover, an ancient population split in its history 2 million generations ago, coupled with only rare gene flow among lineage groups, validates this system as a model for incipient speciation. Low versus high recombination regions of the genome give distinct signatures of population size change through time, indicative of widespread effects of selection on highly linked portions of the genome owing to extreme inbreeding by self-fertilization. Analysis of functional mutations indicates that genomic context, owing to selection that acts on long linkage blocks, is a more important driver of population variation than are the functional attributes of the individually encoded genes.

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