Comment on "Predator classification by the sea pen Ptilosarcus gurneyi (Cnidaria): role of waterborne chemical cues and physical contact with predatory sea stars"

2003 ◽  
Vol 81 (3) ◽  
pp. 556-558 ◽  
Author(s):  
James E Dalby Jr ◽  
Joel K Elliott
Keyword(s):  
Chemical Cues ◽  
Predator Recognition ◽  
Physical Contact ◽  
Sea Stars ◽  
Behavioural Responses ◽  
The 1960S

In their study of behavioural responses of pennatulaceans to physical contact with asteroids in 2002, Weightman and Arsenault claim to be the first to demonstrate that cnidarians have the ability to distinguish predators from nonpredators. In fact, it has been known since at least the 1960s that cnidarians are capable of predator recognition. We briefly describe some of the abundant literature on this topic, especially studies on anthozoans.

Reply to the comment by Dalby and Elliott on "Predator classification by the sea pen Ptilosarcus gurneyi (Cnidaria): role of waterborne chemical cues and physical contact with predatory sea stars"

2003 ◽  
Vol 81 (3) ◽  
pp. 559-561
Author(s):  
Janice O Weightman ◽  
David J Arsenault
Keyword(s):  
Literature Search ◽  
Chemical Cues ◽  
Review Paper ◽  
High Variability ◽  
Physical Contact ◽  
Extensive Literature ◽  
Sea Stars ◽  
Extensive Literature Search ◽  
Made In

The comment of Dalby and Elliott was triggered by a statement we made in a research note to the effect that our study provided the first experimental evidence of predator-classification abilities in cnidarians. Based on an extensive literature search and the appreciation of our manuscript by the reviewers, at the time of publication we believed that this statement was correct. After reviewing the research articles highlighted by Dalby and Elliott, we concur that the statement is incorrect. We discuss some possible reasons why the articles cited by the authors were not found during our literature search, including the use of technical "jargon". In formulating their comment, the authors make several incorrect assumptions, including (i) that our literature search was limited to a single broad review paper and (ii) that we overlooked key information in at least two of the papers we cited. Also, the authors appear to confound predator recognition and predator classification, as some of the articles they cite do not examine predator-classification abilities. Finally, they give the impression that predator-classification abilities are ubiquitous in cnidarians. This appears to be an overstatement, since a number of published studies clearly indicate high variability in the ability of cnidarians to (i) recognize predators and (ii) respond "correctly" according to the relative threat they represent.

Predator classification by the sea pen Ptilosarcus gurneyi (Cnidaria): role of waterborne chemical cues and physical contact with predatory sea stars

2002 ◽  
Vol 80 (1) ◽  
pp. 185-190 ◽  
Author(s):  
Janice O Weightman ◽  
David J Arsenault
Keyword(s):  
Chemical Cues ◽  
Field Experiments ◽  
Physical Contact ◽  
Generalist Predator ◽  
Sea Stars ◽  
Pisaster Ochraceus ◽  
Defensive Responses ◽  
Defensive Behaviours ◽  
Laboratory Bioassays

Using laboratory and field experiments we examined the defensive behaviour of the sea pen Ptilosarcus gurneyi (Gray) towards three species of sea stars representing three levels of predatory threat. In the laboratory we first quantified the behaviour of P. gurneyi following physical contact with the sea stars Dermasterias imbricata (specialist predator), Pycnopodia helianthoides (generalist predator), and Pisaster ochraceus (nonpredator). Whereas the majority (73%) of the sea pens rapidly burrowed into the sediment following contact with D. imbricata, their response to P. helianthoides was highly variable and only 23% exhibited burrowing. In contrast, the response of P. gurneyi to P. ochraceus was weak and similar to that elicited by contact with a glass rod (control). Also, whereas the majority of sea pens displayed colony-wide bioluminescent flashes towards D. imbricata and P. helianthoides, their responses to P. ochraceus and the control were weaker and more localized. We subsequently examined whether waterborne predator chemical cues alone could trigger the defensive responses of P. gurneyi to D. imbricata and P. helianthoides, using laboratory bioassays of varying stimulus intensity. Interestingly, although exposure to chemical cues from predatory sea stars did not elicit any defensive response in P. gurneyi, subsequent physical contact with these predators triggered complete burrowing. Field bioassays using SCUBA yielded similar results, as P. gurneyi did not respond to the proximity of predators but rather delayed its response until physical contact occurred. Our study thus provides the first experimental evidence of predator-classification abilities in cnidarians and suggests that physical contact with predatory sea stars is required to trigger defensive behaviours in P. gurneyi.

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.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

State-run celebration of Liberation Day in Czechoslovakia (based on audiovisual sources)

2019 ◽  
pp. 251-268
Author(s):  
Timur Gimadeev
Keyword(s):  
Political Development ◽  
Communist Regime ◽  
Political Regime ◽  
The Political ◽  
Historical Experience ◽  
History Of ◽  
Post War ◽  
The 1960S ◽  
The Military

The article deals with the history of celebrating the Liberation Day in Czechoslovakia organised by the state. Various aspects of the history of the holiday have been considered with the extensive use of audiovisual documents (materials from Czechoslovak newsreels and TV archives), which allowed for a detailed analysis of the propaganda representation of the holiday. As a result, it has been possible to identify the main stages of the historical evolution of the celebrations of Liberation Day, to discover the close interdependence between these stages and the country’s political development. The establishment of the holiday itself — its concept and the military parade as the main ritual — took place in the first post-war years, simultaneously with the consolidation of the Communist regime in Czechoslovakia. Later, until the end of the 1960s, the celebrations gradually evolved along the political regime, acquiring new ritual forms (ceremonial meetings, and “guards of memory”). In 1968, at the same time as there was an attempt to rethink the entire socialist regime and the historical experience connected with it, an attempt was made to reconstruct Liberation Day. However, political “normalisation” led to the normalisation of the celebration itself, which played an important role in legitimising the Soviet presence in the country. At this stage, the role of ceremonial meetings and “guards of memory” increased, while inventions released in time for 9 May appeared and “May TV” was specially produced. The fall of the Communist regime in 1989 led to the fall of the concept of Liberation Day on 9 May, resulting in changes of the title, date and paradigm of the holiday, which became Victory Day and has been since celebrated on 8 May.

Preliminary testing of the role of exercise and predator recognition for bonytail and razorback sucker

2007 ◽  
Author(s):  
Gordon A. Mueller ◽  
Jeanette Carpenter ◽  
Robert Krapfel ◽  
Chester Figiel
Keyword(s):  
Predator Recognition ◽  
Preliminary Testing

Healing Touch: Clothed Images of the Virgin in Early Modern Portugal

2020 ◽  
pp. 51-78
Author(s):  
Diana Pereira
Keyword(s):  
Early Modern ◽  
Reciprocal Relationship ◽  
Physical Contact ◽  
Religious Art ◽  
Healing Touch ◽  
Devotional Art ◽  
Healing Power ◽  
The Many ◽  
Santa Maria

Over the last decades there was a growing interest in religious materiality, miraculous images, votive practices, and how the faithful engaged with devotional art, as well as a renewed impetus to discuss the long-recognized association between sculpture and touch, after the predominance of the visuality approach. Additionally, the neglected phenomenon of clothing statues has also been increasingly explored. Based on the reading of Santuario Mariano (1707–1723), written by Friar Agostinho de Santa Maria (1642–1728), this paper will closely examine those topics. Besides producing a monumental catalogue of Marian shrines and pilgrimage sites, this source offers a unique insight into the religious experience and the reciprocal relationship between image and devotee in Early Modern Portugal, and is a particularly rich source when describing the believers’ pursuit of physical contact with sculptures. This yearning for proximity is partly explained by the belief in the healing power of Marian sculptures, which in turn seemed to be conveniently transferred to a myriad of objects. When contact with the images themselves was not possible, devotees sought out their clothes, crowns, rosary beads, metric relics, and so forth. Items of clothing such as mantles and veils were particularly used and so it seems obvious they were not mere adornments or donations, but also mediums and extensions of the sculptures’ presence and power. By focusing on the thaumaturgic role of the statues’ clothes and jewels, I will argue how the practice of dressing sculptures was due to much more than stylistic desires or processional needs and draw attention to the many ways believers engaged with religious art in Early Modern Portugal.

scholarly journals The role of adult fiddler crab environmental acoustic cues and chemical cues in stimulating molting of field-caught megalopae

2021 ◽  
Vol 537 ◽  
pp. 151516
Author(s):  
Emily E. Waddell ◽  
Wendy E.D. Piniak ◽  
Kathleen A. Reinsel ◽  
James M. Welch
Keyword(s):  
Chemical Cues ◽  
Fiddler Crab ◽  
Acoustic Cues

scholarly journals Interactions of ants with native and invasive lady beetles and the role of chemical cues in intraguild interference

Chemoecology ◽  
2021 ◽  
Author(s):  
Roman Bucher ◽  
Laura M. Japke ◽  
Ayse Gül Ünlü ◽  
Florian Menzel
Keyword(s):  
Chemical Cues ◽  
Harmonia Axyridis ◽  
Species Recognition ◽  
Lady Beetle ◽  
Lasius Niger ◽  
Beetle Species ◽  
Beetle Elytra ◽  
Lady Beetles ◽  
Ant Aggression

AbstractThe predator-predator naïveté hypothesis suggests that non-native predators benefit from being unknown to native predators, resulting in reduced intraguild interference with native predators. This novelty advantage should depend on the ability of native predators to recognize cues of non-native predators. Here, we compared ant aggression and lady beetle reaction in four native and the invasive lady beetle species Harmonia axyridis. In addition, we tested whether lady beetle cuticular hydrocarbons (CHCs) are involved in species recognition, which might explain naïveté if the invasive species has a specific CHC profile. To this end, we conducted behavioral assays confronting two native ant species with both living lady beetles and lady beetle elytra bearing or lacking CHCs of different lady beetle species. Finally, we characterized CHC profiles of the lady beetles using GC–MS. In general, the aggression of Lasius niger was more frequent than that of Myrmica rubra and L. niger aggression was more frequent towards most native lady beetle species compared to H. axyridis. The removal of CHCs from lady beetle elytra reduced aggression of both ant species. If CHCs of respective lady beetle species were added on cue-free elytra, natural strength of L. niger aggression could be restored. CHC analyses revealed a distinct cue composition for each lady beetle species. Our experiments demonstrate that the presence of chemical cues on the surface of lady beetles contribute to the strength of ant aggression against lady beetles. Reduced aggression of L. niger towards H. axyridis and reduced avoidance behavior in H. axyridis compared to the equally voracious C. septempunctata might improve the invasive lady beetle’s access to ant-tended aphids.

scholarly journals Past and future trends of Egypt’s water consumption and its sources

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Catherine A. Nikiel ◽  
Elfatih A. B. Eltahir
Keyword(s):  
Economic Growth ◽  
Virtual Water ◽  
Comprehensive Analysis ◽  
Future Trends ◽  
Nile Water ◽  
The Gift ◽  
Per Capita ◽  
The 1960S

AbstractFor millennia the Nile supplied Egypt with more water than needed. As the population grew and the economy expanded, demand on water increased accordingly. Here, we present a comprehensive analysis to reconstruct how total demand on water outstripped supply of the Nile water in the late 1970s, starting from a surplus of about 20 km3 per year in the 1960s leading to a deficit of about 40 km3 per year by the late 2010s. The gap is satisfied by import of virtual water. The role of economic growth in driving per capita demand on water is quantified based on detailed analysis of water use by agriculture and other sectors. We develop and test an empirical model of water demand in Egypt that relates demand on water to growth rates in the economy and population. Looking forward, we project that within this decade of the 2020 s, under nominal scenarios of population and economic growth, Egypt is likely to import more virtual water than the water supplied by the Nile, bringing into question the historical characterization of Egypt as “the gift of the Nile”.

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