scholarly journals Effects of group size on the threat-sensitive response to varying concentrations of chemical alarm cues by juvenile convict cichlids

2006 ◽  
Vol 84 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Grant E Brown ◽  
Tony Bongiorno ◽  
Daniel M DiCapua ◽  
Laura I Ivan ◽  
Ellie Roh
Keyword(s):  
Group Size ◽  
Predator Avoidance ◽  
Response Pattern ◽  
Distilled Water ◽  
Alarm Cues ◽  
Response Patterns ◽  
Alarm Cue ◽  
Convict Cichlids ◽  
Graded Response ◽  
Chemical Alarm Cues

The threat-sensitive predator avoidance model predicts that prey should balance the intensity of antipredator responses against perceived predation risk, resulting in a graded response pattern. Recent studies have demonstrated considerable interspecific variation in the intensity of threat-sensitive response patterns, ranging from strongly graded to relatively nongraded or "hypersensitive" threat-sensitive response patterns. Here, we test for intraspecific plasticity in threat-sensitive responses by varying group size. We exposed juvenile convict cichlids, Archocentrus nigrofasciatus (Günther, 1867), as individuals or in small (groups of three) or large (groups of six) shoals to a series of dilutions of conspecific chemical alarm cues and a distilled water control. Singleton cichlids exhibited significant reductions in time spent moving and in frequency of foraging attempts (relative to distilled water controls) when exposed to a 12.5% dilution of conspecific alarm cue, with no difference in response intensity at higher stimulus concentrations, suggesting a nongraded (hypersensitive) response pattern. Small shoals exhibited a similar response pattern, but at a higher response threshold (25% dilution of stock alarm cue solution). Large shoals, however, exhibited a graded response pattern. These results suggest that group size influences the trade-off between predator avoidance and other fitness related activities, resulting in flexible threat-sensitive response patterns.

Antipredator response to injury-released chemical alarm cues by convict cichlid young before and after independence from parental protection

Behaviour ◽  
2002 ◽  
Vol 139 (5) ◽  
pp. 603-611 ◽  
Author(s):  
Shireen Alemadi ◽  
Brian Wisenden
Keyword(s):  
Size Range ◽  
Antipredator Behavior ◽  
Alarm System ◽  
Alarm Cues ◽  
Convict Cichlid ◽  
Antipredator Response ◽  
Convict Cichlids ◽  
Ostariophysan Fishes ◽  
Chemical Alarm Cues ◽  
Before And After

AbstractInjury-released chemical alarm cues are released when predators attack aquatic prey. These cues are generally released only in this context and as such, conspecific alarm cues form an important component of risk assessment. Minnows (Ostariophysi, Cyprinidae) possess a well-developed chemical alarm system. However, minnows do not respond to conspecific injury-released alarm cues until 30 to 50 d post-hatch. Non-ostariophysan fishes respond to chemical alarm cues with antipredator behavior but the ontogeny of this behavior is not known for any species. Here, we test convict cichlids (Acanthopterygii: Cichlidae), a species known to respond to alarm cues as adults. Convict cichlid parents care for their eggs and defend their developing young from predators for 4 to 6 weeks. In our experiment, we tested the ontogeny of antipredator response to chemical alarm cues in young convict cichlids well within and just beyond the size range typically defended by parents. We found that small convict cichlid young of a size typically defended by parents engaged in area avoidance and grouping behaviors in response to alarm cues and did so as effectively as young that would typically be independent of parental care.

Behavioural responses to alarm cues by free-ranging rainbow darters (Etheostoma caeruleum)

Behaviour ◽  
2009 ◽  
Vol 146 (11) ◽  
pp. 1565-1572 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
The Other ◽  
Antipredator Behaviour ◽  
Alarm Cues ◽  
Natural Conditions ◽  
Natural Habitats ◽  
Behavioural Responses ◽  
Alarm Cue ◽  
Chemical Alarm Cues ◽  
Free Ranging ◽  
Etheostoma Caeruleum

AbstractResponses of fishes to chemical alarm cues have been well-documented in the laboratory, but relatively few taxa have been tested under free-ranging conditions in natural habitats. While snorkeling in a stream, we exposed rainbow darters (Etheostoma caeruleum) to skin extracts from conspecifics (alarm cue), skin extracts from heterospecifics (no alarm cue) and a blank control. Darters showed a significantly longer latency to move ('freezing') in the presence of the alarm cue relative to the other two stimuli. These results indicate that rainbow darters can detect chemical alarm cues under natural conditions and respond with appropriate antipredator behaviour.

Quality or quantity? the role of donor condition in the production of chemical alarm cues in juvenile convict cichlids

Behaviour ◽  
2004 ◽  
Vol 141 (10) ◽  
pp. 1235-1248 ◽  
Author(s):  
Reehan Mirza ◽  
Grant Brown ◽  
Ellie Roh
Keyword(s):  
Threshold Concentration ◽  
Response Threshold ◽  
Antipredator Behaviour ◽  
Alarm Cues ◽  
Water Control ◽  
Antipredator Response ◽  
Condition Versus ◽  
Convict Cichlids ◽  
Chemical Alarm Cues ◽  
High Condition

AbstractMuch study has been devoted to the function of chemical alarm cues in predator-prey relationships in aquatic environments, but little is known about the production of these valuable sources of chemosensory information. Recent studies have demonstrated that donor (cue sender) condition may play an important role in the production of chemical alarm cues in juvenile convict cichlids (Archocentrus nigrofasciatus). In laboratory experiments, we conducted trials to test for the effect of donor body condition on the minimum behavioural response threshold and/or intensity of antipredator response to conspecific chemical alarm cues. Chemical alarm cue donors were sampled from high or low condition populations. Pairs of juvenile cichlids were exposed to the skin extracts of high condition versus low condition donors, across a range of relative concentrations (200, 100, 50, 25, and 12.5%), and a distilled water control. We found that cichlids exhibited overt antipredator behaviour beginning at a concentration of 25% for the high condition cue, while a minimum response threshold concentration of 50% was seen for low condition cue. The intensity of antipredator response was greater following exposure to the alarm cues of high condition stimulus versus low condition donors. Taken together, these findings suggest that the damage-released chemical alarm cues from high condition donors are qualitatively and quantitatively greater than those of low condition donors.

LEARNED RECOGNITION OF HETEROSPECIFIC ALARM CUES ENHANCES SURVIVAL DURING ENCOUNTERS WITH PREDATORS

Behaviour ◽  
2002 ◽  
Vol 139 (7) ◽  
pp. 929-938 ◽  
Author(s):  
Douglas Chivers ◽  
Reehan Mirza ◽  
Jeffery Johnston
Keyword(s):  
Yellow Perch ◽  
Pimephales Promelas ◽  
Mixed Diet ◽  
Alarm Cues ◽  
Fathead Minnows ◽  
Culaea Inconstans ◽  
Alarm Cue ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Chemical Alarm Cues ◽  
Chemical Stimuli

AbstractNumerous species of aquatic animals release chemical cues when attacked by a predator. These chemicals serve to warn other conspecifics, and in some cases heterospecifics, of danger, and hence have been termed alarm cues. Responses of animals to alarm cues produced by other species often need to be learned, yet mechanisms of learned recognition of heterospecific cues are not well understood. In this study, we tested whether fathead minnows (Pimephales promelas) could learn to recognize a heterospecific alarm cue when it was combined with conspecific alarm cue in the diet of a predator. We exposed fathead minnows to chemical stimuli collected from rainbow trout, Oncorhynchus mykiss, fed a mixed diet of minnows and brook stickleback, Culaea inconstans, or trout fed a mixed diet of swordtails, Xiphophorous helleri, and stickleback. To test if the minnows had acquired recognition of the heterospecific alarm cues, we exposed them to stickleback alarm cues and introduced an unknown predator, yellow perch (Perca flavescens) or northern pike (Esox lucius). Both perch and pike took longer to initiate an attack on minnows that were previously exposed to trout fed minnows and stickleback than those previously exposed to trout fed swordtails and stickleback. These results demonstrate that minnows can learn to recognize heterospecific alarm cues based on detecting the heterospecific cue in combination with minnow alarm cues in the diet of the predator. Ours is the first study to demonstrate that behavioural responses to heterospecific chemical alarm cues decreases the probability that the prey will be attacked and captured during an encounter with a predator.

scholarly journals Response of pumpkinseed sunfish to conspecific chemical alarm cues: an interaction between ontogeny and stimulus concentration

2003 ◽  
Vol 81 (10) ◽  
pp. 1671-1677 ◽  
Author(s):  
Jason P Marcus ◽  
Grant E Brown
Keyword(s):  
Standard Length ◽  
Relative Concentration ◽  
Lepomis Gibbosus ◽  
Skin Extract ◽  
Distilled Water ◽  
Alarm Cues ◽  
Pumpkinseed Sunfish ◽  
Trade Offs ◽  
Chemical Alarm Cues ◽  
Antipredator Responses

Recent studies have shown that juvenile centrachids undergo ontogenetic shifts in their behavioural response towards conspecific and heterospecific chemical alarm cues based on threat-sensitive trade-offs between the benefits associated with predator avoidance and foraging. We conducted laboratory studies to test the hypothesis that the relative concentration of conspecific alarm cues provides relevant information, allowing individuals to maximize these trade-offs. Juvenile (<40 mm standard length) and subadult (>95 mm standard length) pumpkinseed sunfish (Lepomis gibbosus) were exposed to conspecific skin extracts at stock (undiluted) concentration or diluted 1:1 (50%), 1:3 (25%), or 1:7 (12.5%) with distilled water. Juvenile sunfish exhibited significant antipredator responses (relative to the distilled water controls) when exposed to conspecific skin extracts at a concentration as low as 25%. Juveniles exposed to 12.5% skin extract were not significantly different from the distilled water controls. Subadult sunfish exhibited significant antipredator responses only to the two highest concentrations. In response to the two lowest concentrations (25% and 12.5%), however, subadult sunfish exhibited significant foraging responses. These data demonstrate that the relative concentration of chemical alarm cues provides reliable information and allows individuals to accurately assess local predation risk and hence maximize potential trade-offs.

ONTOGENETIC CHANGES IN RESPONSE TO HETEROSPECIFIC ALARM CUES BY JUVENILE LARGEMOUTH BASS ARE PHENOTYPICALLY PLASTIC

Behaviour ◽  
2002 ◽  
Vol 139 (7) ◽  
pp. 913-927 ◽  
Author(s):  
Devon Gershaneck ◽  
Justin Golub ◽  
Grant Brown ◽  
Desiree Plata
Keyword(s):  
Largemouth Bass ◽  
Standard Length ◽  
Micropterus Salmoides ◽  
Alarm Cues ◽  
Ontogenetic Changes ◽  
Body Type ◽  
Chemical Alarm Cue ◽  
Alarm Cue ◽  
Information Cues ◽  
Chemical Alarm Cues

AbstractJuvenile largemouth bass (Micropterus salmoides) undergo an ontogenetic change in their response to chemical alarm cues of a heterospecific prey guild member (finescale dace, Phoxinus neogaeus), shifting from an antipredator to a foraging response at a standard length of 50 to 55 mm. We conducted a laboratory study to determine if: (1) this shift is fixed or phenotypically plastic, and (2) juvenile bass respond to the alarm cues of a non-Ostariophysan prey guild member. Juvenile bass were reared on high versus low food diets for 10 weeks prior to the experiment, and then exposed to heterospecific skin extracts (the source of chemical alarm cues). When exposed to the skin extracts of finescale dace or green sunfish (Lepomis cyanellus), juvenile bass exhibited a significant positive relationship between standard length and horizontal and vertical area use and time spent moving. In addition, there was a significant effect of body type, with bass with deeper body morphs shifting from antipredator to foraging responses earlier than those with shallower body morphs. Bass exhibited no change in behaviour to swordtail (Xiphophorus helleri) skin extracts, which lack a chemical alarm cue recognized by bass. These data strongly suggest that the developmental point at which bass switch from an antipredator to a foraging response is phenotypically plastic and dependant upon body morphology, and that bass are capable of using the chemical alarm cue of at least two, taxonomically diverse, heterospecific prey guild members as social information cues.

scholarly journals Do juvenile Atlantic salmon (Salmo salar) use chemosensory cues to detect and avoid risky habitats in the wild?

2011 ◽  
Vol 68 (4) ◽  
pp. 655-662 ◽  
Author(s):  
Jae-Woo Kim ◽  
James W.A. Grant ◽  
Grant E. Brown
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Stream Water ◽  
Alarm Cues ◽  
Alarm Cue ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Chemical Alarm Cues ◽  
In The Wild ◽  
Experimental Treatments

We examined whether juvenile Atlantic salmon ( Salmo salar ) in the wild adjust their behaviour in response to chemical cues of predator activity during a 4-week period after emergence from gravel nests. In each of seven 75 m2 sites in Catamaran Brook, New Brunswick, Canada, we established three contiguous sections differing in perceived predator activity by releasing stream water in control sections, conspecific alarm cues in risky sections, and nothing in buffer sections in both 2006 and 2007. As predicted, the density of young-of-the-year (YOY) salmon tended to decrease in alarm cue sections, while it increased in control and buffer sections. After the 2-week manipulation in 2006, we switched treatments so that buffer sections became alarm cue sections and alarm cue sections became buffer sections for an additional 2-week period. After the switch, the number of YOY increased least in the new alarm cue sections and most in control and new buffer sections. In contrast with YOY, the density of age 1+ parr was not affected by the experimental treatments. Our results suggest that YOY salmon can use chemical alarm cues to assess the predator activity of habitats in the wild.

Role for Raphe Magnus Neuronal Responses in the Behavioral Reactions to Colorectal Distension

2004 ◽  
Vol 92 (4) ◽  
pp. 2302-2311 ◽  
Author(s):  
Thaddeus S. Brink ◽  
Peggy Mason
Keyword(s):  
Response Pattern ◽  
Response Magnitude ◽  
Response Patterns ◽  
Neuronal Responses ◽  
Behavioral Reactions ◽  
Colorectal Distension ◽  
Graded Response ◽  
Raphe Magnus ◽  
Switch Type ◽  
Pressor Reaction

The brain stem is necessary for the expression of behavioral reactions to noxious visceral inputs. Neurons in raphe magnus (RM) and the adjacent nucleus reticularis magnocellularis (NRMC) respond to visceral stimuli and can facilitate the behavioral reaction to visceral stimulation. To determine which RM and NRMC cells could play a role in generating the reaction to colorectal distension (CRD), the responses of RM and NRMC cells to multiple intensities of CRD were compared with simultaneously evoked cardiovascular and visceromotor reactions in halothane-anesthetized rats. Most neurons (89%) responded to CRD with one of three basic response patterns. For cells with a graded response pattern, the response magnitude increased with increasing stimulation intensity. For flat responding cells, the response magnitude was not different across suprathreshold stimulation intensities. Finally, neurons with a switch response pattern responded to low- and high-intensity CRD in opposing directions. Cells were either inhibited or excited by CRD in each of these categories. Responses of cells with both graded and switch response patterns were significantly correlated with CRD-evoked tachycardia, pressor reaction, and hunching. The activity of graded-responding cells have the greatest predictive value for CRD-evoked reactions. Flat-responding cells have nonlinear responses that may augment reactions to stimuli above the noxious threshold. Cells with switch type response patterns may contribute to differential reactions evoked by CRD stimuli within the noxious range. In sum, RM and NRMC neurons respond to CRD with a variety of patterns, each of which may contribute to the sculpting of CRD reactions in different ways.

Active space of chemical alarm cue in natural fish populations

Behaviour ◽  
2008 ◽  
Vol 145 (3) ◽  
pp. 391-407 ◽  
Author(s):  
Brian Wisenden
Keyword(s):  
Skin Extract ◽  
Alarm Cues ◽  
Fathead Minnows ◽  
Water Control ◽  
Active Space ◽  
Chemical Alarm Cue ◽  
Alarm Cue ◽  
Predator Attack ◽  
Water Traps ◽  
Chemical Alarm Cues

AbstractChemical cues released from injured fish skin during a predator attack provide reliable information about the presence of predation risk. Here, I report estimates of the area avoided by littoral fishes after experimental release of chemical alarm cues in two small lakes in northern Minnesota. Minnow traps were labeled chemically with either water (control) or skin extract (chemical alarm cue) made from 2 cm2 of cyprinid skin (redbelly dace in experiment 1, fathead minnows in experiment 2). Traps labeled with water were placed 1, 2, or 8 m from traps labeled with alarm cue. After 2 h, water-traps that were either 1 or 2 m distant from an alarm-trap caught significantly fewer fish than water-traps 8 m distant from alarm-traps. Conspecific and heterospecific skin extract produced similar area avoidance by fathead minnows. Redbelly dace showed a larger active space in response to conspecific than heterospecific alarm cues. Brook stickleback showed reduced catches within 2 m of skin extract of fathead minnows. Overall, the radius of active space was between 2 and 8 m under lake conditions with average subsurface currents of 0.82 cm/s. These data are the first field estimates of active space of ostariophysan chemical alarm cues.

Stimulus Ratio Effects on Speech Discrimination by Children and Adults

1991 ◽  
Vol 34 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Joan E. Sussman
Keyword(s):  
Discrimination Task ◽  
Response Pattern ◽  
Response Patterns ◽  
Speech Discrimination ◽  
Adult Group ◽  
Discrimination Accuracy ◽  
Formant Frequency ◽  
Response Strategies ◽  
Place Of Articulation ◽  
Adults And Children

This investigation examined the response strategies and discrimination accuracy of adults and children aged 5–10 as the ratio of same to different trials was varied across three conditions of a “change/no-change” discrimination task. The conditions varied as follows: (a) a ratio of one-third same to two-thirds different trials (33% same), (b) an equal ratio of same to different trials (50% same), and (c) a ratio of two-thirds same to one-third different trials (67% same). Stimuli were synthetic consonant-vowel syllables that changed along a place of articulation dimension by formant frequency transition. Results showed that all subjects changed their response strategies depending on the ratio of same-to-different trials. The most lax response pattern was observed for the 50% same condition, and the most conservative pattern was observed for the 67% same condition. Adult response patterns were most conservative across condition. Differences in discrimination accuracy as measured by P(C) were found, with the largest difference in the 5- to 6-year-old group and the smallest change in the adult group. These findings suggest that children’s response strategies, like those of adults, can be manipulated by changing the ratio of same-to-different trials. Furthermore, interpretation of sensitivity measures must be referenced to task variables such as the ratio of same-to-different trials.

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