The effects of reduced pH on chemical alarm signalling in ostariophysan fishes

2002 ◽  
Vol 59 (8) ◽  
pp. 1331-1338 ◽  
Author(s):  
Grant E Brown ◽  
James C Adrian, Jr. ◽  
Michael G Lewis ◽  
Jon M Tower
Keyword(s):  
Alarm Pheromone ◽  
Pimephales Promelas ◽  
Chemical Mechanism ◽  
Skin Extract ◽  
Alarm Pheromones ◽  
Loss Of Response ◽  
Ostariophysan Fishes ◽  
Antipredator Responses ◽  
Acidic Conditions ◽  
Ph Conditions

Under laboratory conditions, we examined the effects of acute exposure to weakly acidic conditions (pH 6.0) on the ability of fathead minnows (Pimephales promelas) and finescale dace (Phoxinus neogaeus) to detect and respond to conspecific and artificial alarm pheromones. Initially, minnows and dace exhibited normal antipredator responses when exposed to conspecific alarm pheromones under normal (pH 8.0) conditions. When retested at pH 6.0, we observed no significant antipredator response. However, when returned to normal pH conditions, both exhibited normal antipredator responses. Minnows exposed to the putative ostariophysan alarm pheromone (hypoxanthine-3-N-oxide) exhibited a similar trend in behavioural response. Finally, we manipulated the pH of minnow skin extract and hypoxanthine-3-N-oxide to determine the chemical mechanism responsible for this observed loss of response. Minnows exhibited significant antipredator responses to natural and artificial alarm pheromones at normal pH conditions, but did not respond to either stimulus once they had been buffered to pH 6.0 or acidified and rebuffered to pH 7.5. These data suggest that the ability of minnows and dace to detect and respond to alarm pheromones is impaired under weakly acidic conditions and that this loss of response is due to a nonreversible covalent change to the alarm pheromone molecule itself.

scholarly journals Fathead minnows learn to recognize predator odour when exposed to concentrations of artificial alarm pheromone below their behavioural-response threshold

2001 ◽  
Vol 79 (12) ◽  
pp. 2239-2245 ◽  
Author(s):  
Grant E Brown ◽  
James C Adrian, Jr. ◽  
Todd Patton ◽  
Douglas P Chivers
Keyword(s):  
Yellow Perch ◽  
Alarm Pheromone ◽  
Pimephales Promelas ◽  
Behavioural Response ◽  
Response Threshold ◽  
Antipredator Behaviour ◽  
Distilled Water ◽  
Fathead Minnows ◽  
Water Control ◽  
Ostariophysan Fishes

Hypoxanthine-3-N-oxide (H3NO) has been identified as the putative alarm pheromone of ostariophysan fishes. Previously we demonstrated a population-specific minimum behavioural-response threshold in fathead minnows (Pimephales promelas) to a H3NO concentration of approximately 0.4 nM. Minnows may, however, perceive low concentrations of H3NO as a predation threat, even though they do not exhibit an overt behavioural response. We conducted a series of laboratory trials to test the hypothesis that minnows can detect the alarm pheromone at concentrations below the minimum behavioural-response threshold. We exposed predator-naïve fathead minnows to H3NO at concentrations ranging from 0.4 to 0.05 nM paired with the odour of a novel predator (yellow perch, Perca flavescens) or distilled water paired with perch odour. We observed significant increases in antipredator behaviour (increased shoal cohesion, movement towards the substrate, a reduction in feeding, and an increase in the occurrence of dashing and freezing behaviour) in shoals of minnows exposed to a combined cue of 0.4 nM H3NO and perch odour (compared with a distilled-water control), but not by shoals exposed to lower concentrations of H3NO paired with perch odour or those exposed to distilled water paired with perch odour. When exposed to perch odour alone 4 days later, minnows initially conditioned to H3NO at concentrations of 0.4–0.1 nM exhibited significant increases in antipredator behaviour. These data demonstrate that minnows attend to the alarm pheromone at concentrations below the minimum behavioural-response threshold and are able to acquire the ability to recognize a novel predator even though they do not exhibit an overt behavioural response.

scholarly journals Chemical alarm signals in wild Trinidadian guppies (Poecilia reticulata)

1999 ◽  
Vol 77 (4) ◽  
pp. 562-570 ◽  
Author(s):  
Grant E Brown ◽  
Jean-Guy J Godin
Keyword(s):  
Poecilia Reticulata ◽  
Alarm Pheromone ◽  
Field Experiments ◽  
Antipredator Behaviour ◽  
Skin Extract ◽  
Distilled Water ◽  
Alarm Signals ◽  
Alarm Pheromones ◽  
Chemical Alarm Signals ◽  
High Predation

We investigated the presence and possible function of chemical alarm signals (alarm pheromones) in wild Trinidadian guppies (Poecilia reticulata) using laboratory, trapping, and direct field observational methods. In laboratory experiments, female guppies from a population exposed to high predation significantly increased their shoaling, dashing, and freezing behaviours and significantly reduced area use when exposed to the skin extract of sympatric female guppies. When exposed to the skin extract of females from a low-predation population, female guppies from a high-predation population exhibited significant, though smaller, increases in antipredator behaviour. No significant differences in antipredator behaviours were noted when females were exposed to swordtail (Xiphophorus helleri) skin extract, which lacks any known alarm pheromone. We conducted two field experiments to confirm these laboratory results. In a trapping experiment, significantly more guppies were caught in funnel traps labelled with distilled water than in paired traps labelled with sympatric guppy skin extract. In a final experiment, a realistic model of a natural predator (pike cichlid, Crenicichla alta), paired with either sympatric guppy skin extract or distilled water, was presented to groups of free-ranging guppies in pools of a high-predation river. Significantly fewer guppies were observed within a 50-cm radius of the predator model and significantly fewer guppies inspected the model when it was paired with guppy skin extract versus distilled water. Taken together, our results strongly suggest the presence of a chemical alarm signal (alarm pheromone) in the Trinidadian guppy, establish the validity of laboratory and trapping studies in the investigation of chemical alarm signalling, and demonstrate that alarm pheromones may function to mediate predation risk under natural conditions in the guppy.

Anti-Predator Responses To Conspecific and Heterospecific Skin Extracts By Threespine Sticklebacks: Alarm Pheromones Revisited

Behaviour ◽  
1997 ◽  
Vol 134 (15-16) ◽  
pp. 1123-1134 ◽  
Author(s):  
Grant E. Brown ◽  
JEAN-GUY J. Godin
Keyword(s):  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Skin Extract ◽  
Alarm Signals ◽  
Alarm Pheromones ◽  
Ostariophysan Fishes ◽  
Exposed Individual ◽  
Chemical Alarm Signals ◽  
Apeltes Quadracus ◽  
Threespine Sticklebacks

AbstractUnder laboratory conditions, we investigated the presence of chemical alarm signals in the threespine stickleback (Gasterosteus aculeatus). We exposed individual threespine sticklebacks to skin extract of conspecifics originating from either the same or a different population, fourspine sticklebacks (Apeltes quadracus; a member of the same prey guild as the threespine stickleback) or swordtails (Xiphophorus helleri), a species not known to possess alarm pheromones and which is phylogenetically distant and allopatric from the threespine stickleback. Threespine sticklebacks exhibited significant increases in anti-predator behaviour patterns when presented with skin extract from both populations of conspecifics and from fourspine sticklebacks, but not to swordtail skin extract. These results suggest, contrary to previous reports, that threespine sticklebacks possess chemical alarm signals, which appear to be similar to those of Ostariophysan fishes.

scholarly journals Antipredator responses to alarm pheromone in groups of young and/or old thrips larvae

Ethology ◽  
2017 ◽  
Vol 125 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Paulien J. A. de Bruijn ◽  
Maurice W. Sabelis ◽  
Martijn Egas
Keyword(s):  
Alarm Pheromone ◽  
Antipredator Responses

scholarly journals A New pH-Dependent Macrocyclic Rhodamine B-Based Fluorescent Probe for Copper Detection in White Wine

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4514 ◽  
Author(s):  
Nour Doumani ◽  
Elias Bou-Maroun ◽  
Jacqueline Maalouly ◽  
Maya Tueni ◽  
Adrien Dubois ◽  
...  
Keyword(s):  
Rhodamine B ◽  
White Wine ◽  
Green Solvent ◽  
Acidic Media ◽  
One Pot ◽  
Acidic Conditions ◽  
Ph Conditions ◽  
Ph Dependent ◽  
Copper Detection ◽  
Color Emission

For efficiently measuring copper (II) ions in the acidic media of white wine, a new chemosensor based on rhodamine B coupled to a tetraazamacrocyclic ring (13aneN4CH2NH2) was designed and synthesized by a one-pot reaction using ethanol as a green solvent. The obtained chemosensor was characterized via NMR, UV and fluorescent spectra. It was marked with no color emission under neutral pH conditions, with a pink color emission under acidic conditions, and a magenta color emission under acidic conditions where copper (II) ions were present. The sensitivity towards copper (II) ions was tested and verified over Ca2+, Ag+, Zn2+, Mg2+, Co2+, Ni2+, Fe2+, Pb2+, Cd2+, Fe3+, and Mn2+, with a detection limit of 4.38 × 10−8 M in the fluorescence spectrum.

scholarly journals In utero behavioral imprinting to predation risk in pups of the bank vole

2020 ◽  
Vol 74 (2) ◽  
Author(s):  
Thorbjörn Sievert ◽  
Arjane Kerkhoven ◽  
Marko Haapakoski ◽  
Kevin D. Matson ◽  
Olga Ylönen ◽  
...  
Keyword(s):  
Predation Risk ◽  
Open Field ◽  
Bank Vole ◽  
Alarm Pheromone ◽  
Predator Odor ◽  
Myodes Glareolus ◽  
Alarm Pheromones ◽  
Mustela Nivalis ◽  
Wide Range ◽  
Generational Effects

Abstract In the predator–prey arms race, survival-enhancing adaptive behaviors are essential. Prey can perceive predator presence directly from visual, auditory, or chemical cues. Non-lethal encounters with a predator may trigger prey to produce special body odors, alarm pheromones, informing conspecifics about predation risks. Recent studies suggest that parental exposure to predation risk during reproduction affects offspring behavior cross-generationally. We compared behaviors of bank vole (Myodes glareolus) pups produced by parents exposed to one of three treatments: predator scent from the least weasel (Mustela nivalis nivalis); scent from weasel-exposed voles, i.e., alarm pheromones; or a control treatment without added scents. Parents were treated in semi-natural field enclosures, but pups were born in the lab and assayed in an open-field arena. Before each behavioral test, one of the three scent treatments was spread throughout the test arena. The tests followed a full factorial design (3 parental treatments × 3 area treatments). Regardless of the parents’ treatment, pups exposed to predator odor in the arena moved more. Additionally, pups spend more time in the center of the arena when presented with predator odor or alarm pheromone compared with the control. Pups from predator odor–exposed parents avoided the center of the arena under control conditions, but they spent more time in the center when either predator odor or alarm pheromone was present. Our experiment shows that cross-generational effects are context-sensitive, depending on the perceived risk. Future studies should examine cross-generational behavioral effects in ecologically meaningful environments instead of only neutral ones. Significance statement We exposed bank voles to odors signaling predation risk to assess the effects parental predation exposure on the behavior of their offspring. Besides predator odor, we also assessed the role of a conspecific alarm cue as a novel way of spreading the predation risk information. Pup behaviors were assessed in the open-field arena, a standard way of assessing animal behavior in a wide range of contexts. We found that also alarm pheromone increased the time pups spend in the center of the arena similarly to predator odor. While previous studies suggested that offspring would be more fearful, our results indicate that the cross-generational effects are very context-dependent; i.e., they differ significantly depending on which scent cue is presented in the open-field arena. This shows the need for better tools or measurements to translate laboratory results into ecologically meaningful frameworks.

scholarly journals Preparation and Characterization of Alginate and Psyllium Beads ContainingLactobacillus acidophilus

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Farzaneh Lotfipour ◽  
Shahla Mirzaeei ◽  
Maryam Maghsoodi
Keyword(s):  
Lactobacillus Acidophilus ◽  
Encapsulation Efficiency ◽  
Alginate Beads ◽  
Probiotic Bacteria ◽  
Partial Substitution ◽  
Narrow Size Distribution ◽  
Acidic Conditions ◽  
Ph Conditions

This paper describes preparation and characterization of beads of alginate and psyllium containing probiotic bacteria ofLactobacillus acidophilusDMSZ20079. Twelve different formulations containing alginate (ALG) and alginate-psyllium (ALG-PSL) were prepared using extrusion technique. The prepared beads were characterized in terms of size, morphology and surface properties, encapsulation efficiency, viabilities in acid (pH 1.8, 2 hours) and bile (0.5% w/v, 2 hours) conditions, and release in simulated colon pH conditions. The results showed that spherical beads with narrow size distribution ranging from1.59±0.04to1.67±0.09 mm for ALG and from1.61±0.06to1.80±0.07mm for ALG-PSL with encapsulation efficiency higher than 98% were achieved. Furthermore, addition of PSL into ALG enhanced the integrity of prepared beads in comparison with ALG formulations. The results indicated that incorporation of PSL into alginate beads improved viability of the bacteria in acidic conditions as well as bile conditions. Also, stimulating effect of PSL on the probiotic bacteria was observed through 20-hour incubation in simulated colonic pH solution. According to ourin vitrostudies, PSL can be a suitable polymer candidate for partial substitution with ALG for probiotic coating.

Does habitat complexity influence the ability of fathead minnows to learn heterospecific chemical alarm cues?

2003 ◽  
Vol 81 (5) ◽  
pp. 923-927 ◽  
Author(s):  
M S Pollock ◽  
D P Chivers
Keyword(s):  
Habitat Complexity ◽  
Complex Structure ◽  
Pimephales Promelas ◽  
Ecological Factors ◽  
Habitat Characteristics ◽  
Predatory Fish ◽  
Skin Extract ◽  
Alarm Cues ◽  
Fathead Minnows ◽  
Chemical Alarm Cues

Numerous aquatic animals release chemical cues when attacked by a predator. These cues "warn" other individuals of danger and have been termed alarm cues. Cross-species responses to alarm cues are common and in some cases result from learned recognition. However, little is known about the ecological factors that could influence this learned recognition. The current study focuses on the role of habitat complexity in the learning of heterospecific alarm cues. We introduced brook stickleback (Culaea inconstans) into outdoor pools containing fathead minnows (Pimephales promelas) naïve to stickleback. The pools all contained a predatory fish (northern pike, Esox lucius) but varied in habitat characteristics. Pools representing high-complexity habitats had a large amount of structure to obscure the visual environment, while pools representing low-complexity habitats had minimal structure. After 8 days, fish were removed from the pools and behavioural assays were conducted in the laboratory. We tested the minnows for a response to either stickleback skin extract (experimental) or swordtail (Xiphophorus helleri) skin extract (control) and found that minnows conditioned in pools with little structure had learned to recognize stickleback alarm cues, while those from pools with complex structure did not recognize stickleback alarm cues.

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