scholarly journals Predator recognition and anti-predatory behaviour in a recent aquatic invader, the killer shrimp (Dikerogammarus villosus)

2019 ◽  
Author(s):  
Matteo Rolla ◽  
Sonia Consuegra ◽  
Carlos Garcia de Leaniz
Keyword(s):  
Predator Recognition ◽  
Test Arena ◽  
Predatory Behaviour ◽  
Dikerogammarus Villosus ◽  
Fish Kairomones ◽  
Aggregation Behaviour ◽  
Significant Difference ◽  
Fish Predators ◽  
Open Test ◽  
Predator Threat

AbstractThe killer shrimp (Dikerogammarus villosus) is one of the most recent, but also most damaging, aquatic invasive species in Europe, but information on how the species responds to novel predation pressures in recently invaded areas is very limited. We employed an open test arena to examine predator recognition and anti-predatory behaviour in killer shrimp exposed to either blank water or water conditioned with fish kairomones to simulate a predator threat. Within five years after their introduction, killer shrimp spent much more time hiding in the presence of fish kairomones than when they were exposed to blank water. However, no significant difference was found in aggregation behaviour, and killer shrimp were strongly attracted to the scent of conspecifics regardless of predator threat. Given the strong selective pressures that fish predators can exert on native and invasive gammarids, our findings highlight the need to consider prey-predator interactions to better predict the dispersal and likely impact of killer shrimp into invaded ecosystems.

A comparison of the behaviour and performance of sows and piglets in crates and oval pens

1999 ◽  
Vol 69 (2) ◽  
pp. 327-333 ◽  
Author(s):  
R.H. Bradshaw ◽  
D.M. Broom
Keyword(s):  
Litter Size ◽  
Time Lapse ◽  
Production Data ◽  
Aggregation Behaviour ◽  
Significant Difference ◽  
The Mean ◽  
Two Indices ◽  
Time Of Year ◽  
And Performance ◽  
Size At Birth

AbstractA comparison was made of sow lying behaviour, piglet aggregation behaviour and performance in crates (no. = 10) and oval pens (no. = 8). Twenty-four hour time-lapse video tapes were made and a farrowing day defined for each sow by noting the 24-h period during which the sow gave birth (09:00 to 09:00 h). Each sow and litter, balanced for parity and time of year, was analysed from 12:00 to 20:00 h during the 24 h immediately following this day. The following analyses were conducted: (1) the number and type of lying behaviour; (2) each litter was scanned every 10 min and at each lying event the number of piglets within 0·3 m of the sow noted; two indices were then calculated, based on the mean of the 10-min scans and the mean for the lying events, for each sow expressed as a proportion of the total litter size. Any dead piglets were removed and cause of mortality established by post-mortem examination. Production data showed that there was no significant difference between litter size at birth and at weaning but overall level of mortality was higher in the pen compared with the crate due to crushing. The majority of crushing events occurred in the first 3 days after farrowing (crate 75%; oval pen 64%). The total number of lying events and related posture changes did not differ between systems; only ‘roll-over’ events (movement from lateral on one side to the other within 10 s) were higher in the oval pen. There was no difference in the proportion of aggregating piglets at the 10-min scans or the lying events. Increased crushing mortality in the pen does not appear to be due to the aggregation behaviour of piglets but to the increased number of sow roll-over behaviours.

scholarly journals Predatory impact of the freshwater invader Dikerogammarus villosus (Crustacea: Amphipoda)

2002 ◽  
Vol 59 (6) ◽  
pp. 1078-1084 ◽  
Author(s):  
Jaimie T.A Dick ◽  
Dirk Platvoet ◽  
David W Kelly
Keyword(s):  
Great Lakes ◽  
North American ◽  
Field Studies ◽  
Freshwater Ecosystems ◽  
Predatory Behaviour ◽  
Dikerogammarus Villosus ◽  
The North ◽  
North American Great Lakes ◽  
Body Sizes ◽  
Predatory Impact

To assess the increasing threats to aquatic ecosystems from invasive species, we need to elucidate the mechanisms of impacts of current and predicted future invaders. Dikerogammarus villosus, a Ponto–Caspian amphipod crustacean, is invading throughout Europe and predicted to invade the North American Great Lakes. European field studies show that populations of macroinvertebrates decline after D. villosus invasion. The mechanism of such impacts has not been addressed empirically; however, D. villosus is known to prey upon and replace other amphipods. Therefore, in this study, we used microcosm and mesocosm laboratory experiments, with both single and mixed prey species scenarios, to assess any predatory impact of D. villosus on a range of macroinvertebrate taxa, trophic groups, and body sizes. Dikerogammarus villosus predatory behaviour included shredding of prey and infliction of "bite" injuries on multiple victims. Dikerogammarus villosus killed significantly greater numbers of macroinvertebrates than did the native Gammarus duebeni, which is currently being replaced by D. villosus. This invader thus appears to impact on freshwater ecosystems through its exceptional predatory capabilities. We predict that future invasions by D. villosus will have serious direct and indirect effects on freshwaters, with its invasion facilitated in a larger "invasional meltdown" in regions like the North American Great Lakes.

scholarly journals Influence of Food Resource Size on the Foraging Behavior of Nasutitermes corniger (Motschulsky)

Sociobiology ◽  
2018 ◽  
Vol 65 (2) ◽  
pp. 291 ◽  
Author(s):  
Thiago Sampaio de Souza ◽  
Vinícius Siqueira Gazal ◽  
Vinicius José Fernandes ◽  
Ana Carolina Campos de Oliveira ◽  
Elen De Lima Aguiar-Menezes
Keyword(s):  
Rectangular Cross Section ◽  
Food Resource ◽  
Eucalyptus Grandis ◽  
Test Arena ◽  
Nasutitermes Corniger ◽  
Significant Difference ◽  
Influence Of Food ◽  
Chemical Factors ◽  
Mass Recruitment ◽  
Physical And Chemical

In general, termite foraging can be affected by physical and chemical factors linked to food. This study investigated if the wood length of Eucalyptus grandis W. Hill ex Maiden, as a food resource, influences the behavior of foraging events of Nasutitermes corniger (Motschulsky). Nests with mature and active colonies were collected in the field and transferred to glass cubes connected to a test arena under laboratory conditions. Wooden blocks of E. grandis, with a 2.5 x 2.0 cm rectangular cross section, were offered to termites in three different lengths: 5, 10 and 15 cm. Each test was repeated with 20 nests and lasted 60 minutes, when the following behavioral events and their duration were observed: initial exploration, initial recruitment and mass recruitment. At the end of each test, the quantities of termites (total, workers and soldiers) and gnawing workers were determined. The results show that longer blocks favored a higher occurrence of exploration and initial recruitment. However, the highest mass recruitment occurred with the 10 cm blocks. The length of the wood influenced the total number of termites recruited and gnawing workers; both were highest for the 10 cm blocks. There was no significant difference in relation to exploration time of the blocks and number of workers and soldiers recruited. Therefore, we conclude that wood length is a factor that can affect N. corniger foraging.

Effects of Chlorpromazine and Amytal on Hoarding in “Shy” and “Nonshy” Rats

1964 ◽  
Vol 14 (2) ◽  
pp. 359-365 ◽  
Author(s):  
Aurelio A. Torres
Keyword(s):  
Saline Control ◽  
Significant Difference ◽  
Open Test ◽  
Do So

Ss were classified into shy and nonshy groups by means of the cage-emergence technique. A series of trials in either open or closed alleys were given, the last 2 serving as saline control trials for the drug stage. An equal number of shy and nonshy Ss were randomly assigned to sodium amytal or chlorpromazine and 3 open test trials were given. Shy animals hoarded less in the open than in the closed alleys, but there was no significant difference between the two groups in the closed alleys. Sodium amytal effectively increased hoarding in the shy Ss, but chlorpromazine failed to do so. Neither drug had a significant effect upon hoarding of nonshy Ss. The significance of these results was discussed in connection with hoarding levels of shy and nonshy Ss and the effects of the drugs on fear.

Is the reaction to chemical cues of predators affected by age or experience in fire salamanders (Salamandra salamandra)?

2014 ◽  
Vol 35 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Alejandro Ibáñez ◽  
Barbara A. Caspers ◽  
Pilar López ◽  
José Martín ◽  
E. Tobias Krause
Keyword(s):  
Chemical Cues ◽  
Predator Recognition ◽  
Test Arena ◽  
Potential Predator ◽  
Predator Prey ◽  
Chemical Recognition ◽  
Behavioural Reaction ◽  
Salamandra Salamandra ◽  
In Fire

Predation is one of the strongest forces driving natural selection. Predator success reduces future prey fitness to zero. Thus, recognition and avoidance of a potential predator is an essential fitness-relevant skill for prey. Being well equipped in the predator-prey arms race is highly adaptive. In this context we tested whether age and/or potential experience of fire salamanders (Salamandra salamandra) affected their behaviour towards the chemical signature of a potential predator. We evaluated the space use of salamanders in a test arena with a shelter containing chemical cues from a predator (i.e., a rat) and a clean shelter. Our results demonstrate that naïve subadult fire salamanders do show a significant behavioural reaction towards rat odour. However, they do not avoid the chemical cues of the potential predator, but instead have a significant preference for the shelter with rat faeces. In contrast to this, both the naïve adult and wild-caught adult fire salamanders showed neither a preference nor an avoidance of rat scent. These results could suggest a role of age in odour-based predator recognition in salamanders. Similarly, predator recognition through chemical cues could be more important early in life when the young fire salamanders are more vulnerable to predatory attacks and less important in other life stages when salamanders are less subjected to predation. In conclusion, future studies considering wild-caught subadults should disentangle the importance of previous experience for predator chemical recognition.

A co-invasive microsporidian parasite that reduces the predatory behaviour of its host Dikerogammarus villosus (Crustacea, Amphipoda)

Parasitology ◽  
2013 ◽  
Vol 141 (2) ◽  
pp. 254-258 ◽  
Author(s):  
K. BACELA-SPYCHALSKA ◽  
T. RIGAUD ◽  
R. A. WATTIER
Keyword(s):  
Biological Invasions ◽  
Host Population ◽  
Intracellular Parasite ◽  
Healthy Individuals ◽  
Microsporidian Parasite ◽  
Predatory Behaviour ◽  
Dikerogammarus Villosus ◽  
High Position ◽  
Cucumispora Dikerogammari ◽  
Predatory Pressure

SUMMARYParasites are known to affect the predatory behaviour or diet of their hosts. In relation to biological invasions, parasites may significantly influence the invasiveness of the host population and/or mediate the relationships between the invader and the invaded community. Dikerogammarus villosus, a recently introduced species, has had a major impact in European rivers. Notably, its high position in trophic web and high predatory behaviour, have both facilitated its invasive success, and affected other macroinvertebrate taxa in colonized habitats. The intracellular parasite Cucumispora dikerogammari, specific to D. villosus, has successfully dispersed together with this amphipod. Data presented here have shown that D. villosus infected by this parasite have a reduced predatory behaviour compared with healthy individuals, and are much more active suggesting that the co-invasive parasite may diminish the predatory pressure of D. villosus on newly colonized communities.

scholarly journals The Influence of the eyespots of peacock butterfly (Aglais io) and caterpillar on predator recognition

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
JunSung Park ◽  
Dongwan Heo
Keyword(s):  
Survival Rate ◽  
Natural Enemy ◽  
Treated Group ◽  
Predator Recognition ◽  
Control Group ◽  
Significant Difference ◽  
The One

The main purpose of this study is to verify or refute the famous existing theory that the eyespots found on the wings of various insects are a kind of imitation which triggers birds, the predator of insects, to have a sense of avoidance by making them recognize the insects as their predator. The first experiment was conducted on the peacock butterfly using models with eyespots and those without eyespots. A single butterfly model without eyespots was used as the control group, and a pair of a butterfly models with eyespots and another without eyespots was used as the treated group. The butterfly models were attached to trees and the survival rate of the models without eyespots was checked every hour. According to the results of the experiment, it is difficult to conclude that the eyespots of peacock butterfly trigger a sense of avoidance for birds as there was no significant difference in the numbers of the attacked peacock butterfly models without eyespots between the control group and the treated group. The second experiment was conducted using caterpillar models with eyespots and those without eyespots arranged in the same way as the first experiment. However, there was no statistically significant difference in the numbers of attacked caterpillar models between the control group of a caterpillar model without eyespots only and the treated group composed of a pair of caterpillar models without eyespots and the one with eyespots. Thus, the second experiment shows that the caterpillar with eyespots does not imitate the eyes of the predator and it indirectly supports the findings of the first experiment. Through the results of the two experiments, it is possible to refute the existing theory that the eyespots actually imitate the eyes of the natural enemy of the predator.

scholarly journals Effect of ants on Mus musculus Linnaeus, 1758 (Rodentia: Muridae) carcasses decomposition: a preliminary study in the in an Atlantic Forest fragment

2018 ◽  
Vol 19 (3) ◽  
Author(s):  
Laila Fieto Ribeiro ◽  
Tércia Vargas ◽  
Juliane Floriano Lopes
Keyword(s):  
Mus Musculus ◽  
Neotropical Region ◽  
Decomposition Process ◽  
Forest Fragment ◽  
Predatory Behaviour ◽  
Significant Difference ◽  
Average Abundance ◽  
The Common ◽  
Preliminary Study

Different ant species are frequently associated with carcasses during decomposition and they are present from the early until the late postmortem phase. Despite the common presence of Formicidae on carcasses, their role in the decomposition process is generally neglected. Here, we evaluate the effect of ants on Mus musculus decomposition pattern and abundance of associated dipteran fauna in the Neotropical region. We also discussed the role of different ant species in the decomposition process, emphasizing their predatory or necrophagous behaviour. Six carcasses of M. musculus were placed in the field and distributed equally in two treatments: “with ants” and “without ants”. Only in the “without ants” treatment, ants were not allowed to access the carcasses. A total of six ant species were registered on carcasses. The most abundant ant species were Linepithema neotropicum and Pheidole sp., which exhibited an intense predatory behaviour on dipteran larvae, resulting in a delay in the decomposition process. In contrast, Camponotus rufipes workers were observed acting exclusively as necrophagous and their behaviour clearly accelerated the decomposition process on one carcass. Considering the entire decomposition process, the average abundance of adult flies was not different between the two treatments. However, we found a significant difference in the abundance of dipteran larvae between them. Our findings provide a preliminary study about the effect of Neotropical ant species presence on the decomposition pattern. We highlight the contradictory role that different ant species may exhibit on carcasses and how these presented findings could be applied in medico legal reports.

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