Produção de sons em Doradídeos e Auchenopterídeos (Siluriformes, Pisces)

This paper is concerned with sound production of Doradides and Auchenopterides (Siluriformes, Pisces). Field observations (hydrofone recordings) near Manaus, Amazonas and electrophysiological investigations in INPA, Manaus have been made. 1. The drumming apparatus of the Doradides Doras, Megalodoras (Bacu) and Oxydoras (Cuiú-Cuiú) consists of the ramus Mülleri (the elastic spring of the so-called "Springfederapparat), the drumming muscles and the exomembrane. A special quality of the drumming apparatus of these genera is the fact that the elastic spring and the exomembrane are firmly connected by a strong ligament. Thus they build up a compound oscillating system. 2. Acanthodoras (Rabeca) and Trachycorystes (Kangati) have no such ligaments between the elastic spring and the exomembrane. 3. The dramming sounds of Doras and Oxydoras show a pulse repetition rate of 60-90 Hz. This rate corresponds to the frequency of the myogram responses of the dramming muscles during the stimulus-induced grunts. A drumming sound generally lasts about 40-70 msec. 4. The drumming sounds of Acanthodoras (Rabeca) show a fundamental frequency which may range over 250 Hz. In the electrophysiological experiments the frequency of myograms did not exceed 170 Hz during stimulus-induced grunts. The duration of the grunts produced under hand-held-conditions corresponds very well to the duration of the stimulus-induced grunts (100-200 msec). 5. The dramming sounds of Trachycorystes (Kangati) show a fundamental frequency of about 120 Hz. They may last several seconds.Este trabalho apresenta os diferentes modos da produção de sons em Doradidae e Auchenopteridae (Siluriformes, Pisces). Isso está estreitamente relacionado aos resultados das observações no campo e das investigações eletrofisiológicas realizadas no INPA, Manaus (agosto 1975 - fevereiro 1976). 1 O aparelho tamborilador nos DoradideosDoras, Megalodoras (Bacu) e Oxydoras (Cuiú-Cuiú) consiste em uma mola óssea (Ramus Mülleri ou Springfeder), dos músculos tamboriladores e da exomembrana. Um ponto interessante destes gêneros é o fato da mola óssea e a exomembrana estarem firmemente ligados por um tendão muito forte Estas partes formam um sistema oscilatório composto. 2. Acanthodoras (Rabeca) e Trachycorystes (Cangati) não têm estes tendões entre a mola óssea e a exomembrana. 3. Os sons tamborilados de Doras e Oxydoras têm a freqüência fundamental de 60-90 Hz. Esta cota corresponde com a freqüência dos miogramas dos músculos tamboriladores durante a estimulação elétrica Um som tamborilado geralmente dura ca. 40-70 mseg 4. Os sons tamborilados de Acanthodoras (Rabeca) têm uma freqüência fundamental que pode exceder 250 Hz. Nas experiências eletrofisiológicas a freqüência dos miogramas não excede 170 Hz durante a estimulação elétrica. As durações dos sons tamborilados (ao serem segurados pela mão) correspondem às durações dos sons tamborilados causados sob estimulação elétrica da medula (100-200 mseg). 5 Os sons tamborilados de Trachycorystes (Cangati) têm a freqüência fundamental de mais ou menos 120 Hz que podem durar alguns segundos

Social waves in giant honeybees (Apis dorsata) elicit nest vibrations

Giant honeybees (Apis dorsata) nest in the open and have developed a wide array of strategies for colony defence, including the Mexican wave-like shimmering behaviour. In this collective response, the colony members perform upward flipping of their abdomens in coordinated cascades across the nest surface. The time–space properties of these emergent waves are response patterns which have become of adaptive significance for repelling enemies in the visual domain. We report for the first time that the mechanical impulse patterns provoked by these social waves and measured by laser Doppler vibrometry generate vibrations at the central comb of the nest at the basic (=‘natural’) frequency of 2.156 ± 0.042 Hz which is more than double the average repetition rate of the driving shimmering waves. Analysis of the Fourier spectra of the comb vibrations under quiescence and arousal conditions provoked by mass flight activity and shimmering waves gives rise to the proposal of two possible models for the compound physical system of the bee nest: According to the elastic oscillatory plate model, the comb vibrations deliver supra-threshold cues preferentially to those colony members positioned close to the comb. The mechanical pendulum model predicts that the comb vibrations are sensed by the members of the bee curtain in general, enabling mechanoreceptive signalling across the nest, also through the comb itself. The findings show that weak and stochastic forces, such as general quiescence or diffuse mass flight activity, cause a harmonic frequency spectrum of the comb, driving the comb as an elastic plate. However, shimmering waves provide sufficiently strong forces to move the nest as a mechanical pendulum. This vibratory behaviour may support the colony-intrinsic information hypothesis herein that the mechanical vibrations of the comb provoked by shimmering do have the potential to facilitate immediate communication of the momentary defensive state of the honeybee nest to the majority of its members. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00114-013-1056-z) contains supplementary material, which is available to authorized users

Stereoscopic motion analysis in densely packed clusters: 3D analysis of the shimmering behaviour in Giant honey bees

<p>Abstract</p> <p>Background</p> <p>The detailed interpretation of mass phenomena such as human escape panic or swarm behaviour in birds, fish and insects requires detailed analysis of the 3D movements of individual participants. Here, we describe the adaptation of a 3D stereoscopic imaging method to measure the positional coordinates of individual agents in densely packed clusters. The method was applied to study behavioural aspects of shimmering in Giant honeybees, a collective defence behaviour that deters predatory wasps by visual cues, whereby individual bees flip their abdomen upwards in a split second, producing Mexican wave-like patterns.</p> <p>Results</p> <p>Stereoscopic imaging provided non-invasive, automated, simultaneous, <it>in-situ </it>3D measurements of hundreds of bees on the nest surface regarding their thoracic position and orientation of the body length axis. <it>Segmentation </it>was the basis for the <it>stereo matching</it>, which defined correspondences of individual bees in pairs of stereo images. Stereo-matched "agent bees" were re-identified in subsequent frames by the <it>tracking </it>procedure and <it>triangulated </it>into real-world coordinates. These algorithms were required to calculate the three spatial motion components (dx: horizontal, dy: vertical and dz: towards and from the comb) of individual bees over time.</p> <p>Conclusions</p> <p>The method enables the assessment of the 3D positions of individual Giant honeybees, which is not possible with single-view cameras. The method can be applied to distinguish at the individual bee level active movements of the thoraces produced by abdominal flipping from passive motions generated by the moving bee curtain. The data provide evidence that the z-deflections of thoraces are potential cues for colony-intrinsic communication. The method helps to understand the phenomenon of collective decision-making through mechanoceptive synchronization and to associate shimmering with the principles of wave propagation. With further, minor modifications, the method could be used to study aspects of other mass phenomena that involve active and passive movements of individual agents in densely packed clusters.</p

‘Special agents’ trigger social waves in giant honeybees (Apis dorsata)

Giant honeybees (Apis dorsata) nest in the open and have therefore evolved a variety of defence strategies. Against predatory wasps, they produce highly coordinated Mexican wavelike cascades termed ‘shimmering’, whereby hundreds of bees flip their abdomens upwards. Although it is well known that shimmering commences at distinct spots on the nest surface, it is still unclear how shimmering is generated. In this study, colonies were exposed to living tethered wasps that were moved in front of the experimental nest. Temporal and spatial patterns of shimmering were investigated in and after the presence of the wasp. The numbers and locations of bees that participated in the shimmering were assessed, and those bees that triggered the waves were identified. The findings reveal that the position of identified trigger cohorts did not reflect the experimental path of the tethered wasp. Instead, the trigger centres were primarily arranged in the close periphery of the mouth zone of the nest, around those parts where the main locomotory activity occurs. This favours the ‘special-agents’ hypothesis that suggest that groups of specialized bees initiate the shimmering

How to Join a Wave: Decision-Making Processes in Shimmering Behavior of Giant Honeybees (Apis dorsata)

Shimmering is a collective defence behaviour in Giant honeybees (Apis dorsata) whereby individual bees flip their abdomen upwards, producing Mexican wave-like patterns on the nest surface. Bucket bridging has been used to explain the spread of information in a chain of members including three testable concepts: first, linearity assumes that individual “agent bees” that participate in the wave will be affected preferentially from the side of wave origin. The directed-trigger hypothesis addresses the coincidence of the individual property of trigger direction with the collective property of wave direction. Second, continuity describes the transfer of information without being stopped, delayed or re-routed. The active-neighbours hypothesis assumes coincidence between the direction of the majority of shimmering-active neighbours and the trigger direction of the agents. Third, the graduality hypothesis refers to the interaction between an agent and her active neighbours, assuming a proportional relationship in the strength of abdomen flipping of the agent and her previously active neighbours. Shimmering waves provoked by dummy wasps were recorded with high-resolution video cameras. Individual bees were identified by 3D-image analysis, and their strength of abdominal flipping was assessed by pixel-based luminance changes in sequential frames. For each agent, the directedness of wave propagation was based on wave direction, trigger direction, and the direction of the majority of shimmering-active neighbours. The data supported the bucket bridging hypothesis, but only for a small proportion of agents: linearity was confirmed for 2.5%, continuity for 11.3% and graduality for 0.4% of surface bees (but in 2.6% of those agents with high wave-strength levels). The complimentary part of 90% of surface bees did not conform to bucket bridging. This fuzziness is discussed in terms of self-organisation and evolutionary adaptedness in Giant honeybee colonies to respond to rapidly changing threats such as predatory wasps scanning in front of the nest

Social Waves in Giant Honeybees Repel Hornets

Giant honeybees (Apis dorsata) nest in the open and have evolved a plethora of defence behaviors. Against predatory wasps, including hornets, they display highly coordinated Mexican wave-like cascades termed ‘shimmering’. Shimmering starts at distinct spots on the nest surface and then spreads across the nest within a split second whereby hundreds of individual bees flip their abdomens upwards. However, so far it is not known whether prey and predator interact and if shimmering has anti-predatory significance. This article reports on the complex spatial and temporal patterns of interaction between Giant honeybee and hornet exemplified in 450 filmed episodes of two A. dorsata colonies and hornets (Vespa sp.). Detailed frame-by-frame analysis showed that shimmering elicits an avoidance response from the hornets showing a strong temporal correlation with the time course of shimmering. In turn, the strength and the rate of the bees' shimmering are modulated by the hornets' flight speed and proximity. The findings suggest that shimmering creates a ‘shelter zone’ of around 50 cm that prevents predatory wasps from foraging bees directly from the nest surface. Thus shimmering appears to be a key defence strategy that supports the Giant honeybees' open-nesting life-style

Automatic detection of spatio-temporal signaling patterns in cell collectives.

Increasing experimental evidence points to the physiological importance of space-time correlations in signaling of cell collectives. From wound healing to epithelial homeostasis to morphogenesis, coordinated activation of biomolecules between cells allows the collectives to perform more complex tasks and to better tackle environmental challenges. To capture this information exchange and to advance new theories of emergent phenomena, we created ARCOS, a computational method to detect and quantify collective signaling. We demonstrate ARCOS on cell and organism collectives with space-time correlations on different scales in 2D and 3D. We made a new observation that oncogenic mutations in the MAPK/ERK and PIK3CA/Akt pathways of MCF10A epithelial cells hyperstimulate intercellular ERK activity waves that are largely dependent on matrix metalloproteinase intercellular signaling. ARCOS is open-source and available as R and Python packages. It also includes a plugin for the napari image viewer to interactively quantify collective phenomena without prior programming experience

The predator-prey interaction between blue-bearded bee eaters (Nyctyornis athertoni Jardine and Selby 1830) and giant honeybees (Apis dorsata Fabricius 1798)

We investigated the interaction between raiding blue-bearded bee eaters (Nyctyornis athertoni) and counter-attacking bees in an aggregation of 50 giant honeybee (Apis dorsata) colonies on a bee tree in Assam, India. We filmed two scenarios with an Arriflex camera at 150 frames per second: first, the bee eater passed parallel to a nest, threatening only the sunny side of the colony, and second, the bird passed a nest laterally in a perpendicular direction, eliciting release of a great number of guard bees from both sides of the colony. In the first scenario, we assessed more than 700 bees in the mass release, comprising 2-3 per cent of colony members. We found the first evidence for intercolonial group defence in Apis dorsata, which means that colonies or parts of them, which were not directly threatened, joined the defence action of the threatened colony. We discuss how unthreatened nests or parts of them can be challenged for mass release of guard bees