Effects of metamorphosis on the aquatic escape response of the two-lined salamander (Eurycea bislineata)

2002 ◽  
Vol 205 (6) ◽  
pp. 841-849 ◽  
Author(s):  
Emanuel Azizi ◽  
Tobias Landberg
Keyword(s):  
Aspect Ratio ◽  
Escape Response ◽  
Analysis Of Covariance ◽  
Locomotor Performance ◽  
Escape Performance ◽  
Total Length ◽  
Maximum Curvature ◽  
Escape Responses ◽  
Eurycea Bislineata ◽  
Stage 1

SUMMARYAlthough numerous studies have described the escape kinematics of fishes, little is known about the aquatic escape responses of salamanders. We compare the escape kinematics of larval and adult Eurycea bislineata, the two-lined salamander, to examine the effects of metamorphosis on aquatic escape performance. We hypothesize that shape changes associated with resorption of the larval tail fin at metamorphosis will affect aquatic locomotor performance. Escape responses were recorded using high-speed video, and the effects of life stage and total length on escape kinematics were analyzed statistically using analysis of covariance. Our results show that both larval and adult E. bislineata use a two-stage escape response (similar to the C-starts of fishes) that consists of a preparatory (stage 1) and a propulsive (stage 2) stroke. The duration of both kinematic stages and the distance traveled during stage 2 increased with total length. Both larval and adult E. bislineata had final escape trajectories that were directed away from the stimulus. The main kinematic difference between larvae and adults is that adults exhibit significantly greater maximum curvature during stage 1. Total escape duration and the distance traveled during stage 2 did not differ significantly between larvae and adults. Despite the significantly lower tail aspect ratio of adults, we found no significant decrease in the overall escape performance of adult E. bislineata. Our results suggest that adults may compensate for the decrease in tail aspect ratio by increasing their maximum curvature. These findings do not support the hypothesis that larvae exhibit better locomotor performance than adults as a result of stronger selective pressures on early life stages.Movie available on-line: http://www.biologists.com/JEB/movies/jeb3978.html.

scholarly journals Escaping from multiple visual threats: Modulation of escape responses in Pacific staghorn sculpin (Leptocottus armatus).

2021 ◽  
Author(s):  
Hibiki Kimura ◽  
Tilo Pfalzgraff ◽  
Marie Levet ◽  
Yuuki Kawabata ◽  
John F Steffensen ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Escape Response ◽  
The Body ◽  
Body Motion ◽  
Time Interval ◽  
Time Intervals ◽  
Escape Responses ◽  
Leptocottus Armatus ◽  
Stage 1 ◽  
Staghorn Sculpin

Fish perform rapid escape responses to avoid sudden predatory attacks. During escape responses, fish bend their bodies into a C-shape and quickly turn away from the predator and accelerate. The escape trajectory is determined by the initial turn (Stage 1) and a contralateral bend (Stage 2). Previous studies have used a single threat or model predator as a stimulus. In nature, however, multiple predators may attack from different directions simultaneously or in close succession. It is unknown whether fish are able to change the course of their escape response when startled by multiple stimuli at various time intervals. Pacific staghorn sculpin (Leptocottus armatus) were startled with a left and right visual stimulus in close succession. By varying the timing of the second stimulus, we were able to determine when and how a second stimulus could affect the escape response direction. Four treatments were used: a single visual stimulus (control); or two stimuli coming from opposite sides separated by a 0 ms (simultaneous treatment); a 33 ms; or a 83 ms time interval. The 33 ms and 83 ms time intervals were chosen to occur shortly before and after a predicted 60 ms visual escape latency (i.e. during Stage 1). The 0 ms and 33 ms treatments influenced both the escape trajectory and the Stage 1 turning angle, compared to a single stimulation, whereas the 83 ms treatment had no effect on the escape response. We conclude that Pacific staghorn sculpin can modulate their escape response only between stimulation and the onset of the response, but that escape responses are ballistic after the body motion has started.

scholarly journals Effects of Acupuncture on Lowering Blood Pressure in Postmenopausal Women with Prehypertension or Stage 1 Hypertension: A Propensity Score-Matched Analysis

2021 ◽  
Vol 10 (7) ◽  
pp. 1426
Author(s):  
Bok-Nam Seo ◽  
Ojin Kwon ◽  
Siwoo Lee ◽  
Ho-Seok Kim ◽  
Kyung-Won Kang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Diseases ◽  
Propensity Score ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Postmenopausal Women ◽  
Analysis Of Covariance ◽  
Control Group ◽  
Matched Design ◽  
Stage 1

Postmenopausal women have a higher prevalence of hypertension compared to premenopausal women. Hypertension is a risk factor for cardiovascular diseases, the prevalence of which is ever increasing. This study investigated the effects of long-term acupuncture on lowering the blood pressure of postmenopausal women with prehypertension and stage 1 hypertension. Participants were 122 postmenopausal women aged less than 65 years, diagnosed with prehypertension or stage 1 hypertension (systolic blood pressure 120–159 mmHg or diastolic blood pressure 80–99 mmHg). We used a propensity score-matched design. The experimental group (n = 61) received acupuncture for four weeks every six months over a period of two years. The control group (n = 61) received no intervention. An Analysis of covariance (ANCOVA) was performed for the primary efficacy analysis. Relative risk ratios were used to compare group differences in treatment effects. Acupuncture significantly reduced the participants’ diastolic blood pressure (−9.92 mmHg; p < 0.001) and systolic blood pressure (−10.34 mmHg; p < 0.001) from baseline to follow-up. The results indicate that acupuncture alleviates hypertension in postmenopausal women, reducing their risk of developing cardiovascular diseases and improving their health and quality of life.

The C-start escape response ofPolypterus senegalus: bilateral muscle activity and variation during stage 1 and 2

2002 ◽  
Vol 205 (17) ◽  
pp. 2591-2603 ◽  
Author(s):  
Eric D. Tytell ◽  
George V. Lauder
Keyword(s):  
Muscle Activity ◽  
Escape Response ◽  
High Speed ◽  
Wave Speed ◽  
Activity Patterns ◽  
Motor Pattern ◽  
The Body ◽  
Wide Range ◽  
Fast Start ◽  
Stage 1

SUMMARYThe fast-start escape response is the primary reflexive escape mechanism in a wide phylogenetic range of fishes. To add detail to previously reported novel muscle activity patterns during the escape response of the bichir, Polypterus, we analyzed escape kinematics and muscle activity patterns in Polypterus senegalus using high-speed video and electromyography (EMG). Five fish were filmed at 250 Hz while synchronously recording white muscle activity at five sites on both sides of the body simultaneously (10 sites in total). Body wave speed and center of mass velocity, acceleration and curvature were calculated from digitized outlines. Six EMG variables per channel were also measured to characterize the motor pattern. P. senegalus shows a wide range of activity patterns, from very strong responses, in which the head often touched the tail, to very weak responses. This variation in strength is significantly correlated with the stimulus and is mechanically driven by changes in stage 1 muscle activity duration. Besides these changes in duration, the stage 1 muscle activity is unusual because it has strong bilateral activity, although the observed contralateral activity is significantly weaker and shorter in duration than ipsilateral activity. Bilateral activity may stiffen the body, but it does so by a constant amount over the variation we observed; therefore, P. senegalus does not modulate fast-start wave speed by changing body stiffness. Escape responses almost always have stage 2 contralateral muscle activity, often only in the anterior third of the body. The magnitude of the stage 2 activity is the primary predictor of final escape velocity.

scholarly journals Staging of Schizophrenia With the Use of PANSS: An International Multi-Center Study

2019 ◽  
Vol 22 (11) ◽  
pp. 681-697 ◽  
Author(s):  
Konstantinos N Fountoulakis ◽  
Elena Dragioti ◽  
Antonis T Theofilidis ◽  
Tobias Wikilund ◽  
Xenofon Atmatzidis ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Analysis Of Covariance ◽  
Clinical Staging ◽  
Staging Model ◽  
Multi Center Study ◽  
Stage 1

Abstract Introduction A specific clinically relevant staging model for schizophrenia has not yet been developed. The aim of the current study was to evaluate the factor structure of the PANSS and develop such a staging method. Methods Twenty-nine centers from 25 countries contributed 2358 patients aged 37.21 ± 11.87 years with schizophrenia. Analysis of covariance, Exploratory Factor Analysis, Discriminant Function Analysis, and inspection of resultant plots were performed. Results Exploratory Factor Analysis returned 5 factors explaining 59% of the variance (positive, negative, excitement/hostility, depression/anxiety, and neurocognition). The staging model included 4 main stages with substages that were predominantly characterized by a single domain of symptoms (stage 1: positive; stages 2a and 2b: excitement/hostility; stage 3a and 3b: depression/anxiety; stage 4a and 4b: neurocognition). There were no differences between sexes. The Discriminant Function Analysis developed an algorithm that correctly classified &gt;85% of patients. Discussion This study elaborates a 5-factor solution and a clinical staging method for patients with schizophrenia. It is the largest study to address these issues among patients who are more likely to remain affiliated with mental health services for prolonged periods of time.

The kinematics and performance of escape responses of the knifefish Xenomystus nigri

1993 ◽  
Vol 71 (1) ◽  
pp. 189-195 ◽  
Author(s):  
M. A. Kasapi ◽  
P. Domenici ◽  
R. W. Blake ◽  
D. Harper
Keyword(s):  
High Speed ◽  
Longitudinal Axis ◽  
The Body ◽  
Maximum Acceleration ◽  
Low Speed ◽  
Average Maximum ◽  
Morphological Specialization ◽  
Escape Responses ◽  
And Performance ◽  
Stage 1

The kinematics and performance of the escape responses of the knifefish Xenomystus nigri, a fish specialized for low-speed, undulatory median-fin propulsion, were recorded by means of high-speed cinematography. Two types of escape were observed, one involving the formation of a C-shape along the longitudinal axis of the fish (stage 1), followed by a slow recoil of the body (single bend); the other (double bend) involved stage 1 followed by a contralateral bend (stage 2). The pectoral fins were extended throughout escapes of both types. The average maximum acceleration for double bend escapes was 127.98 m∙s−2; acceleration was usually greatest in stage 1. In double bend escapes, turning angles for stages 1 and 2 were not correlated. Pitch and roll orientations change during escapes. In stage 1, the average roll and average pitch were linearly correlated, suggesting that roll was partly responsible for establishing pitch. Knifefish achieved high maximum acceleration relative to other fish. Therefore, performance was not compromised by morphological specialization for low-speed swimming; however, a negative correlation of pitch with acceleration in stage 1 suggested that escapes involve a trade-off between acceleration and confusing a predator by changing planar orientation.

Escape Performance as a Function of Delay of Reinforcement and Inescapable Us Trials

1973 ◽  
Vol 32 (3_suppl) ◽  
pp. 1255-1261 ◽  
Author(s):  
Gene H. Moffat ◽  
Daniel L. Koch
Keyword(s):  
Delay Interval ◽  
Escape Response ◽  
Lever Press ◽  
Aversive Stimulus ◽  
Delay Group ◽  
Escape Performance ◽  
Response Latencies ◽  
Delay Of Reinforcement

College Ss were given 75 lever-press escape trials with omission of entertaining material constituting the aversive stimulus. Reinstatement of the recording occurred either 0, 3, 6, or 9 sec. after the escape response. One-half of Ss in each delay group received 15 inescapable trials immediately prior to the escape trials. The results indicated that response latencies for the escape trials were directly related to the delay interval employed. Inescapable pretraining did not differentially affect performance.

Escape Behaviour of Juvenile Psammodromus Algirus Lizards: Constraint of or Compensation for Limitations in Body Size?

Behaviour ◽  
1995 ◽  
Vol 132 (3-4) ◽  
pp. 181-192 ◽  
Author(s):  
Pilar López ◽  
José Martín
Keyword(s):  
Body Size ◽  
Escape Response ◽  
Environmental Temperature ◽  
Escape Performance ◽  
Escape Behaviour ◽  
Approach Distance ◽  
Air Temperatures ◽  
Psammodromus Algirus ◽  
Using Data ◽  
Short Flight

AbstractWe compared the escape behaviour of juvenile and adult Psammodromus algirus lizards, by using data of escape performance in the laboratory and field observations of escape behaviour. We specifically examined whether a differential escape response is a constraint of body size, or whether juveniles behave differently in order to maximize their escape possibilities taking into account their size-related speed limitations. In the laboratory, juvenile lizards were slower than adult lizards, and escaped during less time and to shorter distances, even when removing the effect of body size. In the field, juveniles allowed closer approaches and after a short flight usually did not hide immediately, but did so after successive short runs if the attack persists. Approach distance of juveniles was not affected by habitat, but initial and total flight distances were shorter in covered microhabitats. There was no significant effect of environmental temperature on approach and initial flight distances of juveniles. However, the total flight distances were significantly correlated with air temperatures.

scholarly journals Male courtship song drives escape responses that are suppressed for successful mating

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eliane Arez ◽  
Cecilia Mezzera ◽  
Ricardo M. Neto-Silva ◽  
Márcia M. Aranha ◽  
Sophie Dias ◽  
...  
Keyword(s):  
Escape Response ◽  
Walking Speed ◽  
Genetic Manipulation ◽  
Courtship Song ◽  
Male Courtship ◽  
Wild Type ◽  
Crucial Component ◽  
Escape Responses ◽  
Sexually Mature

AbstractPersuasion is a crucial component of the courtship ritual needed to overcome contact aversion. In fruit flies, it is well established that the male courtship song prompts receptivity in female flies, in part by causing sexually mature females to slow down and pause, allowing copulation. Whether the above receptivity behaviours require the suppression of contact avoidance or escape remains unknown. Here we show, through genetic manipulation of neurons we identified as required for female receptivity, that male song induces avoidance/escape responses that are suppressed in wild type flies. First, we show that silencing 70A09 neurons leads to an increase in escape, as females increase their walking speed during courtship together with an increase in jumping and a reduction in pausing. The increase in escape response is specific to courtship, as escape to a looming threat is not intensified. Activation of 70A09 neurons leads to pausing, confirming the role of these neurons in escape modulation. Finally, we show that the escape displays by the female result from the presence of a courting male and more specifically from the song produced by a courting male. Our results suggest that courtship song has a dual role, promoting both escape and pause in females and that escape is suppressed by the activity of 70A09 neurons, allowing mating to occur.

scholarly journals Plasticity of Escape Responses: Prior Predator Experience Enhances Escape Performance in a Coral Reef Fish

PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0132790 ◽  
Author(s):  
Ryan A. Ramasamy ◽  
Bridie J. M. Allan ◽  
Mark I. McCormick
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Escape Performance ◽  
Escape Responses

scholarly journals The effects of familiarity on escape responses in the Trinidadian guppy (Poecilia reticulata)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3899 ◽  
Author(s):  
Hayley L. Wolcott ◽  
Alfredo F. Ojanguren ◽  
Miguel Barbosa
Keyword(s):  
Early Life ◽  
Escape Response ◽  
Poecilia Reticulata ◽  
Test Group ◽  
Life Stages ◽  
Early Life Stages ◽  
Early Stages ◽  
Reactive Distance ◽  
Escape Responses ◽  
Predator Evasion

Predation is the main cause of mortality during early life stages. The ability to avoid and evade potential threats is, therefore, favoured to evolve during the early stages of life. It is also during these early stages that the process of familiarization occurs. It has long been recognized that associating with familiar individuals confers antipredator benefits. Yet gaps in our knowledge remain about how predator evasion is affected by social experience during early stages. In this study, we test the hypothesis that familiarization acquired during early life stages improves escape responses. Using the guppy Poecilia reticulata, we examine the effect of different recent social conditions in the three main components of predator evasion. Using high-speed motion analysis, we compared the number of individuals in each test group that responded to a visual stimulus, their reactive distance and magnitude of their response (maximum speed, maximum acceleration and distance) in groups composed either of familiar or non-familiar individuals. Contrary to the prediction, groups composed of familiar individuals were less responsive than groups of unfamiliar individuals. Reactive distance and magnitude of response were more dependent on individual size rather than on familiarity. Larger individuals reached higher maximum speeds and total distances in their escape response. Our result indicates that familiarity is likely to affect behaviour earlier in a predator-prey interaction, which then affects the behavioural component of the response. Taken together, our study contributes to previous ones by distinguishing which components of an escape response are modulated by familiarity.

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