Daily Activity Rhythms Research Articles

Daily rhythms of intestinal cholecystokinin and pancreatic proteases activity in Senegalese sole juveniles with diurnal and nocturnal feeding

The influence of diurnal and nocturnal feeding on daily rhythms of gut levels of cholecystokinin (CCK) and the activity of two key pancreatic proteases, trypsin and chymotrypsin, were examined in juveniles of Senegalese sole (Solea senegalensis), a species with nocturnal habits. Four feeding protocols were performed: P1) One morning meal; P2) Six meals during the light period; P3) Six meals during the dark period; and P4) 12 meals during 24 h. Daily activity patterns of both proteases were remarkably similar and showed a high correlation in all the experimental protocols. In P1, daily patterns of CCK and digestive enzymes showed a single maximum. In P2, CCK levels exhibited two peaks. Digestive enzymes activities showed slightly delayed peaks compared to CCK, although their daily fluctuations were not significant. In P3, intestinal CCK concentration exhibited two peaks at the end of light and dark periods, but only the second one was significant. The first maximum level of chymotrypsin activity occurred 4 h after the first CCK peak, while the second one coincided with the second CCK peak. Fluctuations of trypsin activity were not significant. In P4, CCK concentration showed three small peaks. Digestive enzymes daily fluctuations were not significant, although they showed an inverted trend with respect to CCK. The daily pattern of the gut CCK content in our study is in agreement with the anorexigenic function of this hormone. Our results support the existence of a negative feedback regulatory loop between CCK and pancreatic proteolytic enzymes in Senegalese sole juveniles.

Art Therapy for Treating Anxiety in Adolescents with Psychosomatic Diseases

The purpose of our study was to develop and test a program for treating anxiety and hostility in adolescents with psychosomatic diseases (PSDs) by means of art therapy. Methods and Results: This study included 20 patients with PSDs aged between 15 years and 17 years. The patients’ examination included clinical data analysis, using standard records, and testing, using a questionnaire to reveal the severity of psychopathological symptoms (SCL–90–R, adapted by Tarabrina et al. 1997) and the Bekhterev Institute Personality Questionnaire (BIPQ, 1980). Art therapy sessions were conducted from 11:00 a.m. till 1:00 p.m., which coincides with the transition in the daily rhythm of autonomic nervous system activity and is more suitable for the reserve capabilities of the body. The course consisted of 10 daily 1.5-hour procedures. The controlled study duration was 10±2 days. The examination showed that adolescents with PSDs had an above-normal "Anxiety" (ANX) indicator, according to the SCL-90-R method, and a high score for the "Anxious" type (AT) of attitude toward the disease, according to the Bekhterev Institute Personality Questionnaire (BIPQ). Conclusion: Art therapy for treatment of adolescents with PSD contributed to a normalization of their emotional state, helped them gain new experience in solving problems, and improved the quality of life.

Estimation of spatial and temporal overlap in three ungulate species in a Mediterranean environment

Interspecific interactions are key drivers in structuring animal communities. Sympatric animals may show such behavioural patterns as the differential use of space and/or time to avoid competitive encounters. We took advantage of the ecological conditions of our study area, inhabited by different ungulate species, to investigate the spatial and temporal distribution of Capreolus capreolus, Dama dama and Sus scrofa. We estimated intraspecific interaction arising from the concomitant use of resources by using camera trapping. We collected 2741 videos with the three ungulates, which showed peculiar activity patterns. The three species were observed in all the habitat types of the study area over the four seasons, thus highlighting an evident spatial overlap. Moreover, our analysis demonstrated that the three species did not avoid each other through temporal segregation of their activities, rather showing a high overlap of daily activity rhythms, though with differences among the species and the seasons. Despite the high spatial and temporal overlap, the three species seemed to adopt segregation through fine-scale spatial avoidance: at an hourly level, the proportion of sites where the species were observed together was relatively low. This spatio-temporal segregation revealed complex and alternative behavioural strategies, which likely facilitated intra-guild sympatry among the studied species. Both temporal and spatio-temporal overlap reached the highest values in summer, when environmental conditions were more demanding. Given these results, we may presume that different drivers (e.g. temperature, human disturbance), which are likely stronger than interspecific interactions, affected activity rhythms and fine-scale spatial use of the studied species.

Ethology of Proctacanthus gracilis Bromley, 1928 (Diptera: Asilidae) in Northeastern Florida, U.S.A.

Proctacanthus gracilis Bromley, 1928 forages primarily from vegetation, capturing prey in flight, and immobilizing them in flight or on the ground. Identified prey is in eight insect orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Odonata, and Orthoptera), with Othoptera making up 63.0%. Mating occurs in the tail-to-tail position and oviposition is in the ground. This species exhibits a distinct daily rhythm of activity for feeding and mating. Grooming behavior resembles that described for other species of robber flies. Morphology, habitats and distribution in Florida, resting behavior, and predators and parasites also are discussed.

Intrapopulation genetic variation in the level and rhythm of daily activity in Drosophila immigrans.

Genetic diversity within a population, such as polymorphisms and personality, is considered to improve population performance because such intraspecific variations have the potential to alleviate the competition for a limited resource or the risk of predation and sexual harassment at a population level. Variation in the level and rhythm of daily activity in a population could also affect population performance by directly altering ecological, social, and sexual interactions among individuals. However, it remains to be elucidated whether such intra‐population variation in the level and rhythms of daily activity exists in a natural population. Here, we investigated the genetic variation in daily activity within a single natural population of Drosophila immigrans. We established 21 isofemale lines from a single natural population and measured larval activity level and the level and daily pattern of adult activity over a 24 hr period. Larval activity level significantly varied among isofemale lines. Likewise, the activity level in the adult stage significantly varied among lines. The significant variation was also found in the daily pattern of adult activity; some lines showed greater activity level in the daytime, and others showed greater activity level in the night. Our results consistently suggest that there is a genetic variation in behavioral activity in a natural population, probably contributing to shaping the population performance.

Exploitation of Outgoing and Incoming Telephone Calls in the Context of Circadian Rhythms of Social Activity Among Elderly People: Observational Descriptive Study.

BackgroundIn the elderly population, analysis of the circadian rhythms of social activity may help in supervising homebound disabled and chronically ill populations. Circadian rhythms are monitored over time to determine, for example, the stability of the organization of daily social activity rhythms and the occurrence of particular desynchronizations in the way older adults act and react socially during the day. Recently, analysis of telephone call detail records has led to the possibility of determining circadian rhythms of social activity in an objective unobtrusive way for young patients from their outgoing telephone calls. At this stage, however, the analysis of incoming call rhythms and the comparison of their organization with respect to outgoing calls remains to be performed in underinvestigated populations (in particular, older populations).ObjectiveThis study investigated the persistence and synchronization of circadian rhythms in telephone communication by older adults.MethodsThe study used a longitudinal 12-month data set combining call detail records and questionnaire data from 26 volunteers aged 70 years or more to determine the existence of persistent and synchronized circadian rhythms in their telephone communications. The study worked with the following four specific telecommunication parameters: (1) recipient of the telephone call (alter), (2) time at which the call began, (3) duration of the call, and (4) direction of the call. We focused on the following two issues: (1) the existence of persistent circadian rhythms of outgoing and incoming telephone calls in the older population and (2) synchronization with circadian rhythms in the way the older population places and responds to telephone calls.ResultsThe results showed that older adults have their own specific circadian rhythms for placing telephone calls and receiving telephone calls. These rhythms are partly structured by the way in which older adults allocate their communication time over the day. In addition, despite minor differences between circadian rhythms for outgoing and incoming calls, our analysis suggests the two rhythms could be synchronized.ConclusionsThese results suggest the existence of potential persistent and synchronized circadian rhythms in the outgoing and incoming telephone activities of older adults.

One out of ten: low sampling efficiency of cloth dragging challenges abundance estimates of questing ticks

Hard ticks (Acari: Ixodidae) act as important vectors of zoonotic pathogens. For instance, Borrelia burgdorferi s.l. spirochetes pose a severe health risk as aetiological agents of Lyme borreliosis. Commonly, to study the abundance of questing (host-seeking) ticks, a 1 m2 piece of cloth is dragged over vegetation for a determined distance. Here, we designed a tick-sampling study to estimate the sampling efficiency of this standard method. We established 10 m dragging transects in a hemiboreal mixed forest patch in SW Finland for a 5-day monitoring period. Five of the transects were cloth-dragged 3× a day, whereas another five transects were dragged 6× a day in a manner that after each morning, midday and afternoon dragging, a second dragging was conducted on the same transect immediately. Captured Ixodes ricinus ticks were subsequently analysed for tick-borne pathogens. The initial population size of nymphal ticks on a transect was approximated by the accumulated nymph catch from the dragging sessions. The sampling efficiency of the cloth dragging was low, as a single dragging in a previously untouched vegetation strip always caught less than 12% (mean 6%) of the estimated population of active nymphs that were assumed to be questing during the study. Clear results were not found for daily activity rhythm, as ticks were caught in all daily dragging sessions. Approximately every third nymph and every second adult carried a pathogen, but nothing indicated that the occurrence of a pathogen affected the likelihood of the tick being caught by cloth dragging. Our results suggest that only a minority of active ticks can be caught by a single cloth dragging. The abundance estimates in many tick investigations might thus be downward biased.

Wheel-Running Behavior Is Negatively Impacted by Zinc Administration in a Novel Dual Transgenic Mouse Model of AD.

Alzheimer’s disease (AD) is a neurocognitive disorder that impacts both the brain and behavior. Metal ions, including zinc (Zn), have been seen to play an important role in AD-related pathology. In this study, we show alterations in wheel-running behavior both early and late in disease progression in a novel dual Tg mouse model of AD. This mouse includes both amyloid and tau pathology through its cross with the J20 (hAPP) and P301L (Tau) parentage. Animals were given either lab water or water that had been supplemented with 10 ppm Zn. Wheel running was assessed through individually housing mice and measuring wheel-running activity in both the light and dark cycles. Dual Tg mice showed significantly less activity in the first part of the dark cycle than WT mice at both 3.5 and 7 months of age (p < 0.05). Dual Tg mice given Zn water showed less activity compared to dual Tg mice on lab water, tau mice on Zn water, or WT mice given either lab or Zn water (p < 0.05) at 7 months. Female mice in this study consistently showed higher activity compared to male mice in all groups whereas Zn led to reduced activity. Daily activity rhythm was altered in both the tau and dual Tg mice, and Zn impacted this alteration through effects on amyloid, tau, and through circadian pathways.

A Robust and Self-Sustained Peripheral Circadian Oscillator Reveals Differences in Temperature Compensation Properties with Central Brain Clocks.

SummaryCircadian clocks are characterized by three properties: they run in constant conditions with a period of ∼24 h, synchronize to the environmental cycles of light and temperature, and are temperature compensated, meaning they do not speed up with temperature. Central brain clocks regulate daily activity rhythms, whereas peripheral clocks are dispersed throughout the body of insects and vertebrates. Using a set of luciferase reporter genes, we show that Drosophila peripheral clocks are self-sustained but over-compensated, i.e., they slow down with increasing temperature. In contrast, central clock neurons in the fly brain, both in intact flies and in cultured brains, show accurate temperature compensation. Although this suggests that neural network properties contribute to temperature compensation, the circadian neuropeptide Pigment Dispersing Factor (PDF) is not required for temperature-compensated oscillations in brain clock neurons. Our findings reveal a fundamental difference between central and peripheral clocks, which likely also applies for vertebrate clocks.

Does social thermal regulation constrain individual thermal tolerance in an ant species?

In ants, social thermal regulation is the collective maintenance of a nest temperature that is optimal for individual colony members. In the thermophilic ant Aphaenogaster iberica, two key behaviours regulate nest temperature: seasonal nest relocation and variable nest depth. Outside the nest, foragers must adapt their activity to avoid temperatures that exceed their thermal limits. It has been suggested that social thermal regulation constrains physiological and morphological thermal adaptations at the individual level. We tested this hypothesis by examining the foraging rhythms of six populations of A. iberica, which were found at different elevations (from 100 to 2,000m) in the Sierra Nevada mountain range of southern Spain. We tested the thermal resistance of individuals from these populations under controlled conditions. Janzen's climatic variability hypothesis (CVH) states that greater climatic variability should select for organisms with broader temperature tolerances. We found that the A. iberica population at 1,300m experienced the most extreme temperatures and that ants from this population had the highest heat tolerance (LT50=57.55°C). These results support CVH's validity at microclimatic scales, such as the one represented by the elevational gradient in this study. Aphaenogaster iberica maintains colony food intake levels across different elevations and mean daily temperatures by shifting its rhythm of activity. This efficient colony-level thermal regulation and the significant differences in individual heat tolerance that we observed among the populations suggest that behaviourally controlled thermal regulation does not constrain individual physiological adaptations for coping with extreme temperatures.

Lower activity of salivary alpha-amylase in youths with depression

Measurement of basal and stress-induced salivary alpha-amylase activity may help to understand autonomic nervous system disturbance in mental disorders. The potential sympathetic nervous system dysregulation in children and adolescent psychopathologies is mostly unknown. The present study was aimed to test the hypothesis that salivary alpha-amylase activity is higher in youths diagnosed with depression than in healthy subjects considering a part of the daily rhythm of enzyme activity and its morning to midday slope. A total of 30 children aged 15 ± 0.46 years (15 patients with depression, 4 boys, 11 girls, and 15 sex- and age-matched healthy controls) participated in the study. Two saliva samples were collected from each subject to measure activity of alpha-amylase in the morning and midday. The results of the present study revealed that the midday but not morning alpha-amylase activity was lower in patients with depression than in healthy controls. The diurnal increase in enzyme activity present in healthy subjects was absent in patients. The children and adolescents with depression exhibited flatter morning to midday slopes of alpha-amylase activity. In conclusion, the present results indicate a disturbance of alpha-amylase daily rhythm in youths with depression and motivate further studies on the relationship between sympathetic activation and mood disorders.

Misadjustment of diurnal expression of core temperature and locomotor activity in lactating rabbits associated with maternal over-nutrition before and during pregnancy.

Metabolic parameters ranging from circulating nutrient levels and substrate utilization to energy expenditure and thermogenesis are temporally modulated by the circadian timing system. During critical embryonic developmental periods, maternal over-nutrition could alter key elements in different tissues associated with the generation of circadian rhythmicity, compromising normal rhythmicity development. To address this issue, we determine whether maternal over-nutrition leads to alterations in the development of circadian rhythmicity at physiological and behavioral levels in the offspring. For this, female rabbits were fed a standard diet (SD) or high-fat and carbohydrate diet (HFCD) before mating and during gestation. Core body temperature and gross locomotor activity were continuously recorded in newborn rabbits, daily measurements of body weight and the amount of milk ingested was carried out. At the end of lactation, tissue samples, including brown adipose tissue (BAT) and white adipose tissue (WAT), were obtained for determining the expression of uncoupling protein-1 (UCP1) and cell death-inducing DNA fragmentation factor-like effector A (CIDEA) genes. HFCD pups exhibited conspicuous differences in the development of the daily rhythm of temperature and locomotor activity compared to the SD pups, including a significant increase in the daily mean core temperature, changes in the time when temperature or activity remains above the average, shifts in the acrophase, decrease in the duration and intensity of the anticipatory rise previous to nursing, and changes in frequency of the rhythms. HFCD pups exhibited a significant increase in BAT thermogenesis markers, and a decrease of these markers in WAT, indicating more heat generation by brown adipocytes and alterations in the browning process. These results indicate that maternal over-nutrition alters offspring homeostatic and chronostatic regulation at the physiological and behavioral levels. Further studies are needed to determine whether these alterations are associated with the changes in the organization of the circadian system of the progeny.

Behavioral rhythms of an opportunistic predator living in anthropogenic landscapes

BackgroundHuman activities have profoundly altered the spatio-temporal availability of food resources. Yet, there is a clear lack of knowledge on how opportunistic species adapt to these new circumstances by scheduling their daily rhythms and adjust their foraging decisions to predicable patterns of anthropic food subsidies. Here, we used nearly continuous GPS tracking data to investigate the adaptability of daily foraging activity in an opportunistic predator, the yellow-legged gull (Larus michahellis), in response to human schedules.MethodsBy using waveform analysis, we compared timing and magnitude of peaks in daily activity of different GPS-tracked individuals in eleven different habitat types, in relation to type of day (i.e., weekday vs. weekend).ResultsDaily activity rhythms varied greatly depending on whether it was a weekday or weekend, thus suggesting that gulls’ activity peaks matched the routines of human activity in each habitat type. We observed for the first time two types of activity as modelled by waveforms analysis: marine habitats showed unimodal patterns with prolonged activity and terrestrial habitats showed bimodal patterns with two shorter and variable activity peaks.ConclusionsOur results suggest that gulls are able to fine-tune their daily activity rhythms to habitat-specific human schedules, since these likely provide feeding opportunities. Behavioral plasticity may thus be an important driver of expansive population dynamics. Information on predictable relationships between daily activity patterns of gulls and human activities is therefore relevant to their population management.

Motor Transitions’ Peculiarity of Heterozygous DAT Rats When Offspring of an Unconventional KOxWT Mating

Causal factors of psychiatric diseases are unclear, due to gene × environment interactions. Evaluation of consequences, after a dopamine-transporter (DAT) gene knock-out (DAT-KO), has enhanced our understanding into the pathological dynamics of several brain disorders, such as Attention-Deficit/Hyperactivity and Bipolar-Affective disorders. Recently, our attention has shifted to DAT hypo-functional (heterozygous, HET) rodents: HET dams display less maternal care and HET females display marked hypo-locomotion if cared by HET dams (Mariano et al., 2019). We assessed phenotypes of male DAT-heterozygous rats as a function of their parents: we compared “maternal” origin (MAT-HET, obtained by breeding KO-male rats with WT-female dams) to “mixed” origin (MIX-HET, obtained by classical breeding, both heterozygous parents) of the allele. MAT-HET subjects had significantly longer rhythms of daily locomotor activity than MIX-HET and WT-control subjects. Furthermore, acute methylphenidate (MPH: 0, 1, 2 mg/kg) revealed elevated threshold for locomotor stimulation in MAT-HETs, with no response to the lower dose. Finally, by Porsolt-Test, MAT-HETs showed enhanced escape-seeking (diving) with more transitions towards behavioral despair (floating). When comparing both MAT- and MIX-HET to WT-control rats, decreased levels of DAT and HDAC4 were evident in the ventral-striatum; moreover, with respect to MIX-HET subjects, MAT-HET ones displayed increased DAT density in dorsal-striatum. MAT-HET rats displayed region-specific changes in DAT expression, compared to “classical” MIX-HET subjects: greater DAT availability may elevate threshold for dopamine action. Further behavioral and epigenetic characterizations of MAT-HETs, together with deeper characterization of maternal roles, could help to explore parent-of-origin mechanisms for such a peculiar phenotype.

The locomotory activity patterns of the arid-dwelling desert hedgehog, Paraechinus aethiopicus, from Saudi Arabia

The animal-environment interaction is complex, and the ability to temporally organise locomotor activity provides adaptive and survival advantages. The daily and circadian rhythms of locomotor activity in the Desert hedgehog, Paraechinus aethiopicus, from the central deserts of Saudi Arabia were investigated under controlled laboratory conditions. Twelve individuals were subjected to different light cycles of approximately 3 weeks each: light/dark (12:12LD) cycle; a period of constant darkness (DD); an inverse of the LD (12:12 DL) cycle; a short day cycle (8:16LD); and a long day cycle (16:8LD). All the animals exhibited entrainment of their activity to the LD and DL lighting regimes. Locomotor activity of the Desert hedgehog occurred mostly during the dark phases of the LD, DL, long day and short day cycles. All entraining hedgehogs showed daily rhythmicity, with the periods of the rhythms very close to 24 h. Entrained hedgehogs, additionally, inversed their activity patterns when the light cycle was inversed. The Desert hedgehog, therefore, can be described as genuinely nocturnal with an endogenous rhythm of locomotor activity.

Impact of Urban Environment on Students’ Daily Rhythms and Sleep Patterns

This article presents the results of a research of the sleep patterns of 200 students living in dormitories in Moscow. The average duration of night sleep in the surveyed group was 6h 37min. The proportion of students satisfied with the duration of night sleep was 36.5 %. Daily activity rhythms, in particular, the going to sleep and awakening time at the same time, are compiled by 47.5 % of the surveyed students. 86.5 % of students go to bed after midnight. The most late going to sleep time is observed among students of the 1st and 4th years. 37 % of students suffer from insomnia, which is most often caused by stress and work in extracurricular time. It was found that the best indicators of well-being and learning ability were observed at night sleep duration from 6 to 8 hours. When the duration of night sleep is less than 6 hours, there was a deterioration in the state of students’ health, wellbeing and learning ability. It was revealed that 92.2 % of students who fall ill three or more times a year have a night sleep duration of less than 6 hours.

Analysis of the activity rhythm of the predatory bug Orius sauteri (Poppius) (Heteroptera: Anthocoridae) for optimizing its selective light attraction

The minute pirate bug Orius sauteri (Poppius) (Heteroptera: Anthocoridae) is a major natural enemy of micro-pests and is expected to be an effective pest-control agent in Asia. Recently, the violet wavelength has been found to attract several natural enemies, and we proved that violet illumination can increase the O. sauteri population and decrease the pest populations on crops. To optimize this attraction strategy for natural enemies, knowledge of their daily activity rhythm is indispensable. In this study, we examined the daily distribution of O. sauteri activity and determined the lighting time appropriate for selective attraction. Under artificial light–dark cycles, O. sauteri displayed a typical diurnal rhythm that peaked from 9 to 12 h after light-on and declined after light-off, regardless of the photoperiod. A similar activity rhythm was confirmed under natural light. Importantly, the activity remained for around 2 h after sunset, even in complete darkness. Considering the diurnality of micro-pests, we conclude that the most efficient lighting time for the selective attraction of this natural enemy to crops is during the 2 h after sunset.

Activity Rhythms of Coexisting Red Serow and Chinese Serow at Mt. Gaoligong as Identified by Camera Traps.

Simple SummaryHow congeneric species with similar realized niches manage to coexist is a central question in the study of biodiversity. Here, we examined the daily activity rhythm of two coexisting serow species in a mid-mountain humid evergreen broadleaf forest. We used camera traps in a five-year survey at Mt. Gaoligong, western Yunnan, China. We compared the daily activity rhythm of the rare red serow (Capricornis rubidus), a medium-sized solitary ungulate, with the coexisting Chinese serow (C. milneedwardsii milneedwardsii). Although their overall daily activity rhythms were similar, the rare red serow tended to range, feed, and stay vigilant from afternoon through midnight throughout the year. By contrast, Chinese serows preferred to be active from sunrise to noon in the wet season, but shifted their activities and behaviors to afternoon and midnight in the dry season. Interestingly, we found red serows sometimes ranging together with Chinese serows. When they encountered each other, red serows altered their activity patterns more notably, while Chinese serows significantly increased their activity level. These findings are understandable given their similar resource requirements. Although exploitative competitors, red and Chinese serow coexist by avoiding interference competition by altering their respective activity patterns in time.Surveying the activity rhythms of sympatric herbivorous mammals is essential for understanding their niche ecology, especially for how they partition resources and their mechanisms of coexistence. Over a five-year period, we conducted infrared camera-trapping to monitor the activity rhythms of coexisting red serow (Capricornis rubidus) and Chinese serow (C. milneedwardsii milneedwardsii) in the remote mountainous region of Pianma, Mt. Gaoligong, Yunnan, China. Cameras captured images of red serow and Chinese serow on 157 and 179 occasions, respectively. We used circular kernel density models to analyze daily activity rhythms and how temporal variations in activity ensure their co-existence. Although their overall activity levels and patterns were similar, temporal activity and behavior partitioning among the two species occurred during the wet season. Compared with Chinese serows, red serows exhibited less variable daily activity levels, patterns, as well as feeding and vigilance behaviors between seasons. When the two species occasionally ranged together, red serows tended to alter their activity pattern while Chinese serows significantly increased their activity level. Red serow and Chinese serow are exploitative competitors but coexist by altering their daily activity rhythms when in contact and changing activity patterns during the wet season, enabling their coexistence.

Microplastics induce transcriptional changes, immune response and behavioral alterations in adult zebrafish

Microplastics have become pervasive environmental pollutants in both freshwater and marine ecosystems. The presence of microplastics have been recorded in the tissues of many wild fish species, and laboratory studies have demonstrated that microplastics can exert adverse health effects. To further investigate the biological mechanisms underlying microplastics toxicity we applied an integrated approach, analyzing the effects of microplastics at transcriptomic, histological and behavioral level. Adult zebrafish have been exposed to two concentrations of high-density polyethylene and polystyrene microplastics for twenty days. Transcriptomic results indicate alterations in the expression of immune system genes and the down-regulation of genes correlated with epithelium integrity and lipid metabolism. The transcriptomic findings are supported by tissue alterations and higher occurrence of neutrophils observed in gills and intestinal epithelium. Even the daily rhythm of activity of zebrafish appears to be affected, although the regular pattern of activity is recovered over time. Considering the transcriptomic and histological findings reported, we hypothesize that the effects on mucosal epithelium integrity and immune response could potentially reduce the organism defense against pathogens, and lead to a different utilization of energy stores.

A Study of Population Size and Activity Patterns and Their Relationship to the Prey Species of the Eurasian Lynx Using a Camera Trapping Approach.

Simple SummaryThe Eurasian lynx has a wide distribution range in China, but lynx field studies in China are rare compared to those for European populations. Using camera trapping data, this paper reports the lynx population size, activity patterns, and variation within the prey community at a nature reserve in Inner Mongolia. The results found that there were at least 20 lynx in this reserve, and the population has increased steadily over years. There is a seasonal difference in the daily activity rhythms of lynx. The total activity rhythm of lynx is synchronous with five mammal species: hare, red deer, wild boar, raccoon dog, and badger. Red fox and roe deer showed a timed avoidance of lynx to some extent. The present study sets an example for biodiversity conservation; the recovery of prey communities through habitat management should be a priority in determining the restoration of large carnivore populations in China.Revealing the behavioral relationships between predators and their prey is fundamental in understanding the community structure and ecosystem functions of such animals. This study aimed at detecting the population size and activity patterns of Eurasian lynx (Lynx lynx) (along with its prey) by camera trapping monitoring from 2014 to 2017 at the Saihanwula nature reserve in central Inner Mongolia. The total effective trapping days were 29,892 and 20 lynx were identified from 343 trapping photos based on the inner side patterns of their forelimbs. The daily activity rhythms of the lynx overlapped with those of different prey in different seasons. The yearly activity pattern of the lynx was influenced by its main prey’s biology. In conclusion, this study reveals that the activity patterns of the top predator matched those of its prey in different time periods. Habitat management strategies promoting the restoration of prey communities would benefit the lynx in maintaining a stable community structure.